Cerclage for sonographic short cervix in singleton gestations without prior spontaneous preterm birth: systematic review and meta-analysis of randomized controlled trials using individual patient-level data

Development and validation of a cost-effective DIY simulation model for McDonald cerclage training

PURPOSE

The prevention of preterm birth is a challenging task for obstetricians. Cervical cerclage, used as both a primary and secondary prevention method for spontaneous preterm birth, is a crucial surgical intervention. It is essential that obstetricians can learn this procedure in a simulated environment before performing the stitches on high-risk patients. This study aimed to develop a simulator based on 3D printing and evaluate its validity for clinical training.

METHODS

The objectives of this study were (1) to design and construct a cost-effective simulator for McDonald cerclage with two different cervix models-a closed cervix and a cervix with bulging membranes-using common material from a DIY store and 3D printing technology and (2) to validate its effectiveness through feedback from learners and experts in cervical cerclage. The self-made simulator was evaluated by obstetricians using a questionnaire with Likert scale.

RESULTS

Obstetricians and gynecologists assessed the simulator and found it useful for learning and practicing cervical cerclage. The simulator was deemed valuable for skill training.

CONCLUSION

Cervical cerclage is a complex procedure that should be mastered through simulation rather than initial practice on real patients. Our simulator is a cost-effective model suitable for various clinical settings. It has been validated by obstetricians for both preventive and therapeutic cerclage, demonstrating its efficacy for training in cerclage techniques. Future research should focus on less skilled obstetricians and gynecologists and investigate how repeated use of the simulator can enhance their performance in cerclage stitching.

Cerclage in singleton pregnancies with no prior spontaneous preterm birth and short cervix: a randomized controlled trial

BACKGROUND

Preterm birth remains a leading cause of neonatal morbidity and mortality. Cerclage for short cervical length ≤25 mm in patients with singleton pregnancies with a history of spontaneous preterm birth is associated with decreased neonatal morbidity/mortality. Both vaginal progesterone and cerclage individually have level 1 evidence supporting benefit in the prevention of preterm birth in pregnancies complicated by short cervical length. However, there is a paucity of level 1 evidence regarding the potential benefit of cerclage with progesterone relative to progesterone alone for short cervical length ≤25 mm in patients with singleton pregnancies without a history of spontaneous preterm birth.

OBJECTIVE

This study aimed to conduct a pragmatic randomized controlled trial to evaluate the additional benefit of cerclage with vaginal progesterone relative to vaginal progesterone alone in patients with singleton pregnancies without prior spontaneous preterm birth and with a current midtrimester transvaginal ultrasound cervical length ≤25 mm.

STUDY DESIGN

This was a multicenter international randomized controlled trial conducted from September 2017 to September 2023, involving 4 sites in the United States and Italy. Patients with singleton pregnancies without prior spontaneous preterm birth received transvaginal ultrasound cervical length (universal) screening during the midtrimester anatomy ultrasound examination as part of routine care. Inclusion criteria included transvaginal ultrasound cervical length ≤25 mm at 18 0/7 to 23 6/7 weeks. Exclusion criteria included current or planned cerclage, cervical dilation, symptoms of labor, infection, bleeding, and rupture of membranes at screening. Participants were randomized in a 1:1 ratio to cerclage with vaginal progesterone (200-mg vaginal progesterone daily) or vaginal progesterone alone. Randomization was stratified by study site and transvaginal ultrasound cervical length ≤15 mm. The primary outcome was preterm birth <35 weeks, assessed using intention-to-treat analysis. Secondary outcomes included preterm birth <37, 32, 28, and 24 weeks, gestational age at delivery, latency to delivery, and neonatal outcomes. Categorical variables were compared using the Pearson chi-square test and relative risk estimates with 95% confidence intervals. Continuous variables were compared using the Mann-Whitney U test. Latency to delivery and gestational age at delivery were also compared using Kaplan-Meier survival curves. Planned enrollment was set at N=206 on the basis of an estimated 0.54 relative risk with cerclage and a 34% incidence of preterm birth with standard care. The trial was registered on ClinicalTrials.gov (NCT03251729) on June 22, 2017.

RESULTS

Enrollment ran from September 22, 2017 to October 31, 2023, and was halted early because of lagging enrollment. A total of 93 participants were randomized; 3 were excluded because of withdrawal (n=1) and loss to follow-up (n=2). Of the 90 participants included in the intention-to-treat analysis, 43 were assigned to cerclage and progesterone and 47 to progesterone alone. Overall, 40 participants (40.4%) had a transvaginal ultrasound cervical length ≤15 mm. There was no significant difference in the primary outcome of preterm birth <35 weeks between those randomized to cerclage with progesterone vs progesterone alone (16.3% vs 23.4%; relative risk, 0.70 [0.30-1.63]). Those randomized to cerclage with progesterone had significantly increased latency from randomization to delivery (median difference, 13 [5-20] days; P=.01) and a significantly later gestational age at delivery (median difference, 1.0 [0.2-1.7] weeks; P=.035). A Kaplan-Meier survival curve also demonstrated increased latency to delivery and gestational age at delivery for cerclage with progesterone compared with progesterone alone (Mantel-Cox log-rank P<.001 and P=.003, respectively). These findings persisted within both subgroups of cervical length ≤15 mm and 16 to 25 mm.

CONCLUSION

In singleton gestations without a prior spontaneous preterm birth and a transvaginal ultrasound cervical length ≤25 mm before 24 weeks, cerclage with progesterone was not found to significantly reduce the preterm birth rate compared with progesterone alone. However, cerclage and progesterone did result in a significantly longer latency from randomization to delivery and a significantly later gestational age at delivery, compared to progesterone alone. These results suggest the potential benefit of cerclage and progesterone relative to progesterone alone in patients with singleton pregnancies without a prior spontaneous preterm birth and a short cervical length ≤25 mm before 24 weeks. This trial was halted early, and these findings should be confirmed in a larger trial or meta-analysis. El resumen está disponible en Español al final del artículo.

[Primary and secondary cerclage in high-risk pregnant women: Influence on prolongation of pregnancy and preterm birth]

INTRODUCTION

The aim of the study was to evaluate the effectiveness of cerclage in women with previous late miscarriages or premature births. The primary aim was to prolong pregnancy and achieve a term delivery. Secondarily, it was investigated whether an intervention after an early pathological 75-g-oGTT result influences these endpoints.

METHODS

A total of 133 cases were analyzed retrospectively. 80 women underwent primary cerclage between the 14th and 16th week of pregnancy; 53 women underwent secondary cerclage after cervical shortening of less than 25 mm. This group was further subdivided into therapeutic and emergency cerclage groups. Women with early pathologic 75-g-oGTT were treated diabetologically.

RESULTS

Primary cerclage prolonged pregnancy by 20.6 weeks and led to a term delivery in 51 women (63.8%). In the group with secondary cerclage, 25 women (47.2%) had a term delivery with a prolongation of 20.1 weeks. For amniotic sac prolapse, the prolongation was 7.9 weeks. Pathological 75-g-oGTT results were found in 63 women. Early intervention had no significant effect on prolongation and term delivery.

CONCLUSION

Primary cerclage was more effective in achieving term delivery. Women with therapeutic cerclage without amniotic sac prolapse also benefited. With cervical shortening without prolapse, the prolongation was the same in both groups. The worst outcome was observed in emergency cerclage with amniotic sac prolapse. An early 75-g-oGTT is important in order to recognize and treat gestational diabetes in time.

How MRI imaging for an ovarian cyst led to diagnosis of short cervix

BACKGROUND

Magnetic resonance imaging (MRI) during pregnancy is a growing diagnostic modality for a variety of different indications including fetal anomalies and maternal masses. A literature search did not find any case reports diagnosing a short cervix on MRI before 20 weeks gestation.

CASE PRESENTATION

A 34-year-old female underwent magnetic resonance imaging for further evaluation of a known ovarian cyst which demonstrated a multiseptated cystic mass measuring 15.5 × 9.9 × 18.5 cm in the right adnexa at 19 weeks gestation. An incidental finding on MRI of "bulging of membranes into the cervical canal to the level of the external os" was noted. The patient had 3 prior full-term cesarean deliveries with no history of short cervix. Ultrasound confirmed dilated cervix with no measurable cervix. The patient underwent a rescue cerclage.

CONCLUSION

This case describes an unmeasurable cervix diagnosed incidentally during an MRI to characterize a large adnexal mass. In pregnancy, MRI can be a useful imaging modality to evaluate fetal anatomy, placental position and implantation, and abdominal and pelvic structures. In this case, evaluation of the uterus and cervix during imaging for an adnexal mass allowed for detection of an unmeasurable cervix and intervention with a rescue cerclage.

Ultrasound-indicated and physical examination-indicated cervical cerclage in twin versus singleton gestations

AIM

To compare the safety and efficacy of ultrasound- and physical examination-indicated cervical cerclage in twin versus singleton gestations.

METHODS

A retrospective cohort study of all ultrasound-indicated (cervical length ≤ 25 mm) and physical examination-indicated cerclage cases performed over a 9-year period. The primary outcome was the time interval from cerclage placement to delivery.

RESULTS

The study cohort included 94 singleton and 16 twin pregnancies. The time interval from cerclage placement to delivery was comparable in singleton and twin gestations (14.77 vs. 12.07 weeks, p = 0.11), as were the rates of preterm births before 28 and 32 weeks. The rate of alive newborns >24 weeks was lower in the twin group (71.9% vs. 88.3%, p = 0.028). Regression analysis identified that cervical dilation, but not twin gestation, was the only factor independently associated with an increased risk for birth before 32 weeks.

CONCLUSION

Ultrasound-indicated and physical examination-indicated cerclage had comparable efficacy in prolonging pregnancy in twin and singleton gestations, though live birth rates were lower in twins.

Efficacy of ultrasound-indicated cerclage without prior preterm birth

AIM

Our study aimed to evaluate the effectiveness of ultrasound-indicated cerclage in singleton pregnancies with cervical shortening (<25 mm), excluding those with a history of preterm birth (PTB) and infection/inflammation.

MATERIALS AND METHODS

Among the 1556 women admitted for a cervix measuring <25 mm via transvaginal ultrasound at Juntendo University Urayasu Hospital between January 2001 and December 2023, our study focused on 47 singleton patients with no prior history of PTB. After receiving information on both risks and benefits, 25 patients opted for ultrasound-indicated cerclage (cerclage group), while 22 chose expectant management (expectant management group). All participants underwent screening for infection/inflammation of the lower genital tract. The primary outcome, the rate of PTB (<37 weeks', <34 weeks', and <28 weeks' gestation), was assessed in both groups.

RESULTS

The cerclage group demonstrated a significantly lower rate of PTB before 37 and 34 weeks' gestation. Although there was no statistically significant difference, the cerclage group exhibited a delay of 3.6 weeks in the average week of gestation compared to the expectant management group. Notably, the hospitalization period in the cerclage group was significantly reduced by 42 days.

CONCLUSION

Performing an ultrasound-indicated cerclage in cases of a short cervical length <25 mm without a prior history of PTB and infection/inflammation reduces the rates of PTB (<37 and <34 weeks' gestation) and hospitalization period.

Racial and Ethnic Disparities in Cervical Insufficiency, Cervical Cerclage, and Preterm Birth

Background: The frequency of cervical insufficiency differs among the major racial and ethnic groups, with limited data specific to Asian American and Native Hawaiian/Pacific Islander (AANHPI) subpopulations. We assessed cervical insufficiency diagnoses and related outcomes across 10 racial and ethnic groups, including disaggregated AANHPI subgroups, in a large population-based cohort. Study Design: We performed a retrospective cohort study of all singleton births between 20-42 weeks' gestation in California from 2007 to 2018. Logistic regression models were performed to estimate the odds of cervical insufficiency and, among people with cervical insufficiency, the odds of cerclage and preterm birth according to self-reported race and ethnicity. Results: Among 5,114,470 births, 38,605 (0.8%) had a diagnosis code for cervical insufficiency. Compared with non-Hispanic White people, non-Hispanic Black people had the highest odds of cervical insufficiency (adjusted odds ratio [aOR] 3.07; 95% confidence interval [CI], 2.97, 3.18), for cerclage placement and higher odds for preterm birth. Disaggregating AANHPI subgroups showed that Indian people had the highest odds (aOR 1.94; 95% CI, 1.82, 2.07) of cervical insufficiency and had significantly higher odds of cerclage without increased odds of preterm birth; Southeast Asian people had the highest odds of preterm birth. Conclusion: Within a large, diverse population-based cohort, non-Hispanic Black people experienced the highest rates of cervical insufficiency, and among those with cervical insufficiency, had among the highest rates of cerclage and preterm birth. Among AANHPI subgroups specifically, Indian people had the highest rates of cervical insufficiency and cerclage placement, without increased rates of preterm birth; Southeast Asian people had the highest rates of preterm birth, without increased rates of cerclage. Disaggregating AANHPI subgroups identifies important differences in obstetric risk factors and outcomes.

Cervical cerclage vs cervical pessary in women with cervical insufficiency: A multicentric, open-label, randomised, controlled pilot trial [the CEPEIC trial]

Objective

Cervical insufficiency accounts for 8 % of preterm births. Pessary and cerclage are considered preventive approaches for preterm birth. These interventions were compared in terms of reducing the prematurity rate in women with previous preterm birth, due to cervical insufficiency or due to having a short cervix in their current pregnancy.

Methods

This was a prospective, multicentric, open-label, randomised, pilot, controlled trial. Participants were women with singleton pregnancies who had previous preterm birth caused by cervical insufficiency or previous preterm birth and a short cervix [≤ 25 mm] in their current pregnancy. Women were randomised [1:1] to either cerclage or pessary. The primary outcome was to assess the feasibility of a trial on cervical pessary vs. cerclage to prevent preterm birth before 34 weeks in women with cervical insufficiency. As a secondary outcome, we studied the morbidity rate of the pessary versus the cerclage in women with cervical insufficiency and assessed the financial impact of using both devices in these women. The sample size was calculated based on the estimated population that we could potentially recruit: 60 women, 30 for each group, to ascertain whether the rate of preterm birth < 34 weeks of gestation may be reduced from 34 % to at least 27 % in the pessary group, as in the results obtained with the cerclage.

Results

No significant differences in preterm birth < 34 weeks of gestation were observed in our study, although it was underpowered to detect these differences [the relative risk [RR] of PB < 34 weeks of gestation was 0.8 [95 % CI: 0.31-2.09, p = 0.888]. The rates of obstetric and perinatal complications were similar for both devices [15 cases in both groups, 50 % of cases [RR; 0.6-1.68; p = 1]. Cervical pessary had fewer secondary effects than the cerclage [less bleeding at insertion in the pessary group compared with cerclage, 1 case vs 14 cases, p < 0.001; less pain at removal in the pessary group compared with cerclage, 14 vs 22 cases. p = 0.042 and less bleeding, 2 cases vs. 10 cases, p = 0.027].

Conclusions

Pessary does not seem less effective than cerclage, although these findings need to be confirmed in a larger randomised controlled trial. Pessary had fewer secondary effects than cerclage both at insertion and removal.

Sinopsis

Cervical pessary does not seem to be less effective than cerclage. Cervical pessary had fewer secondary effects than cerclage.

Predictors of preterm birth following emergency and ultrasound-indicated cervical cerclage: A retrospective study on 136 singleton pregnancies

OBJECTIVE

We aimed to retrospectively evaluate obstetric and neonatal outcomes in patients who underwent ultrasound-indicated and rescue cervical cerclage and to identify predictors for cerclage failure and consequent preterm birth (PTB).

MATERIALS AND METHODS

We conducted a retrospective analysis on singleton pregnancies between 16 and 27 weeks of gestation who presented with a transvaginal sonographic cervical length (TVS-CL) <25 mm and a previous PTB/second-trimester miscarriage or prolapsed amniotic membranes and/or a TVS-CL <15 mm and underwent cervical cerclage at Mangiagalli Center, Milan, between September 2011 and December 2021. Univariate and multivariate logistic regression analyses were used to identify possible predictive factors of cerclage failure.

RESULTS

During the study period, a total of 136 singletons met the inclusion criteria. Overall, 3 % of pregnancies did not reach fetal viability, mostly due to post-cerclage preterm premature rupture of membranes and/or chorioamnionitis. The mean gestational age at delivery was 35.9 ± 4.5 weeks. Neonates were delivered beyond 37 weeks in 63.2 % of cases, between 28 and 37 weeks in 26.5 %, and less than 28 gestational weeks in 10.3 %. At the multivariate analysis, independent risk factors for miscarriage or PTB were cervical length <10 mm (odds ratio, OR 3.44), advanced cervical dilatation (OR 4.76), and in vitro fertilization (OR 4.66). A history of previous miscarriage, premature delivery, and uterine malformations did not increase the risk of post-cerclage delivery before 37 weeks. In the preterm delivery group, 14 % of patients experienced preterm premature rupture of membranes (pPROM) and 10 % had chorioamnionitis, while no case was registered in the term delivery group. A positive vaginal swab at the time of cervical cerclage was not significantly associated with PTB at the multivariate analysis but it emerged as a significant risk factor for both chorioamnionitis (OR 11.03) and pPROM (OR 5.28).

CONCLUSIONS

Ultrasound-indicated and rescue cervical cerclage were effective in prolonging pregnancy, even when placed beyond 24 weeks of gestation. Preoperative cervical length of less than 10 mm, advanced dilatation, and in vitro fertilization are associated with an increased risk of cerclage failure. A positive vaginal swab before cerclage is associated with increased rates of intrauterine infectious-inflammatory processes.

Rate of preterm delivery and latency period in asymptomatic patients undergoing cerclage for very short cervix ≤10.0 mm

BACKGROUND

In asymptomatic women with cervical length ≤10 mm, vaginal progesterone has a limited effect in reducing the rate of preterm delivery.

OBJECTIVE

This study aimed to estimate the rate of preterm delivery and mean latency period to delivery in asymptomatic women with no history of preterm delivery and a cervical length of ≤10.0 mm undergoing or not undergoing cerclage and who were not treated with vaginal progesterone.

STUDY DESIGN

This was a retrospective analysis of asymptomatic patients with singleton pregnancies and no history of preterm delivery with an incidental finding of a cervical length of ≤10.0 mm measured by transvaginal ultrasound during midtrimester scan. Of note, 56 patients (63.6%) underwent cerclage placement and 32 patients (36.4%) did not, none of them received vaginal progesterone. Patients with evidence of advanced dilation, prolapsing membranes, ruptured membranes, or positive signs of infection were not candidates for cerclage placement and were excluded from the analysis. Differences in the prevalence of preterm delivery, mean gestational age at delivery, and mean latency from very short cervix identification to delivery between the 2 groups were calculated. Associations between cerclage and preterm delivery adjusted for maternal characteristics and fetal weight were estimated.

RESULTS

The median gestational ages at the time of cervical length measurement were 20 6/7 weeks (interquartile range, 17 5/7 to 23 3/7) in the cerclage group and 21 5/7 weeks (interquartile range, 17 6/7 to 23 6/7) in the no-cerclage group (P=.02). No difference in cervical length was observed between patients who had a cerclage (5.9±3.1 mm) and those who did not have a cerclage (6.5±3.2 mm) (P=.4). The prevalence of preterm delivery in women with cerclage vs women without cerclage was as follows: PTD at <37 weeks of gestation (31/56 [55.3%] in the cerclage group vs 28/32 [87.5%] in the no-cerclage group; adjusted odds ratio, 0.17; 95% confidence interval, 0.05-0.62; P=.008), PTD at ≤34 weeks of gestation (27/56 [48.2%] in the cerclage group vs 24/32 [75.0%] in the no-cerclage group; adjusted odds ratio, 0.16; 95% confidence interval, 0.05-0.55; P=.02), and PTD at ≤28 weeks of gestation (19/56 [33.9%] in the cerclage group vs 22/32 [68.7%] in the no-cerclage group; adjusted odds ratio, 0.15; 95% confidence interval, 0.05-0.51; P=.002). The median gestational ages at delivery were 32 6/7 weeks (interquartile range, 19 1/7 to 40 1/7) in the cerclage group and 28 1/7 weeks (interquartile range, 20 1/7 to 40 2/7) in the no-cerclage group (P=.001). The median latencies from the time of cervical length measurement to delivery were 84 days (interquartile range, 8-144) in the cerclage group and 43 days (interquartile range, 1-146) in the no-cerclage group (P=.003).

CONCLUSION

Among low-risk asymptomatic women with a very short cervix (≤10.0 mm) in the midtrimester of pregnancy, women treated with cerclage have an increased latency to delivery and a lower prevalence of preterm delivery than those treated with expectant management.

Changing Indications for Cervical Cerclage Following the Introduction of Routine Ultrasound Surveillance of Cervical Length for Prediction and Prevention of Preterm Birth

Background

Preterm birth (PTB) is associated with significant neonatal mortality and morbidity. Universal measurement of cervical length has been proposed as a screening tool to direct intervention to prevent PTB.

Aim

To assess the impact of the introduction of sonographic mid-trimester cervical length screening on the use of cervical cerclage and PTB.

Material and Methods

A retrospective cohort study reviewed two groups of women who underwent cervical cerclage before and after the introduction of universal sonographic cervical length screening. Demographics and outcomes were compared using Student's t test, Fisher's Exact test and Kaplan-Meier analysis.

Results

Following introduction of universal cervical length screening, the overall rate of cerclage increased from 2.5/1000 births to 6.0/1000 births (p < 0.01). There was a reduction in the proportion of sutures placed purely based on maternal history (50.0% to 30.4%; p < 0.001), while the proportion of sutures placed following ultrasound assessment increased in both high- (21.7 to 36.6%) and low-risk (11.7% to 30.4%) women (p < 0.001). The overall rate of PTB <37 weeks in women has a cerclage was 25.7% and was highest in women undergoing rescue cerclage (64.3%; p < 0.01). There was no difference in the rate of PTB between high- and low-risk women undergoing history- or ultrasound-indicated cerclage. Mean pregnancy length was most prolonged in low-risk women undergoing ultrasound-indicated cerclage, extending gestation from 33.9 to 38.3 weeks (p < 0.01).

Conclusion

Universal cervical length screening results in an increase in the use of cerclage, specifically on the basis of the ultrasound findings. Women who were at low risk but then underwent ultrasound-indicated cerclage experienced most prolongation of pregnancy. Women who were at high risk but had a suture on the basis of ultrasound findings-indicated cerclage represent an alternative method of management with no significant difference in the gestational age of delivery.

Antenatal reproductive screening for pregnant people including preconception: Provides the best reproductive opportunity for informed consent, quality, and safety

INTRODUCTION

This antenatal screening review will include reproductive screening evidence and approaches for pre-conception and post-conception, using first to third trimester screening opportunities.

METHODS

Focused antenatal screening peer-reviewed publications were evaluated and summarized.

RESULTS

Evidenced-based reproductive antenatal screening elements should be offered and discussed, with the pregnancy planning or pregnant person, during Preconception (genetic carrier screening for reproductive partners, personal and family (including reproductive partner) history review for increased genetic and pregnancy morbidity risks); First Trimester (fetal dating with ultrasound; fetal aneuploidy screening plus consideration for expanded fetal morbidity criteria, if appropriate; pregnant person preeclampsia screening; early fetal anatomy screening; early fetal cardiac screening); Second Trimester for standard fetal anatomy screening (18-22 weeks) including cardiac; pregnant person placental and cord pathology screening; pregnant person preterm birth screening with cervical length measurement); Third Trimester (fetal growth surveillance; continued preterm birth risk surveillance).

CONCLUSION

Antenatal reproductive screening has multiple elements, is complex, is time-consuming, and requires the use of pre- and post-testing counselling for most screening elements. The use of preconception and trimesters 'one to three' requires clear patient understanding and buy-in. Informed consent and knowledge transfer is a main goal for antenatal reproductive screening approaches.

Cerclage Plus Adjuvant Vaginal Progesterone for Preterm Birth Prevention in Patients with a Short or Dilated Cervix without Prior Preterm Birth

OBJECTIVE

 The primary objective was to determine if vaginal progesterone following cerclage for cervical length <10 mm or cervical dilation in patients without a history of spontaneous preterm birth (sPTB) decreased the risk of preterm birth at <34 weeks' gestation compared with cerclage alone. Secondary objectives were to determine if vaginal progesterone following cerclage (1) decreased the risk of preterm birth at <24, <28, and <37 weeks' gestation and (2) increased the latency period from cerclage placement to delivery compared with treatment with cerclage alone.

STUDY DESIGN

 Multicenter retrospective cohort study from 2015 to 2020 of singleton pregnancies, without prior sPTB, who had cerclage placement <24 weeks' gestation for cervical length <10 mm or cervical dilation. Exposure defined as cerclage plus vaginal progesterone postoperatively (dual therapy) and unexposed as cerclage alone (monotherapy), based on surgeon preference.

RESULTS

 We included 122 patients, 78 (64%) treated with dual therapy and 44 (36%) treated with monotherapy. In the crude analysis, dual therapy was associated with a lower risk of delivery at <28 weeks' gestation (13%) compared with monotherapy (34%; crude risk ratio: 0.38 [95% confidence interval (CI): 0.19-0.75]). When adjusted for preoperative vaginal progesterone, results were attenuated (adjusted risk ratio: 0.45 [95% CI: 0.20-1.01]). In both the crude and adjusted analyses, the risk of sPTB was not statistically different at <24, <34 or <37 weeks' gestation. Dual therapy was associated with a greater pregnancy latency from cerclage to delivery (16.3 vs. 14.4 weeks; p = 0.04), and greater gestational age at delivery (37.3 vs. 35.8 weeks' gestation; p = 0.02) compared with monotherapy.

CONCLUSION

 While not statistically significant, the risk of sPTB was lower at all gestational ages studied in patients treated with dual therapy compared with monotherapy. Dual therapy was associated with longer pregnancy latency and greater gestational age at delivery compared with monotherapy.

KEY POINTS

· Dual therapy did not decrease preterm birth risk compared with monotherapy.. · Dual therapy prolonged pregnancy compared with monotherapy.. · Dual therapy can be considered but further studies are needed..

The Effect of Maternal Parity on Preterm Birth Risk in Women with Short Mid-Trimester Cervical Length: A Retrospective Cohort Study

Objectives: To evaluate the effect of maternal parity on the association between mid-trimester cervical length and preterm birth to elucidate the potential intricacies of this relationship. Methods: A retrospective cohort study using Electronic Medical Records (EMR) data. The study population included pregnant women with a singleton fetus and a short mid-trimester cervical length, recorded in the EMR system at a large health maintenance organization. Women were categorized by parity in the current pregnancy, and a statistical analysis was conducted to examine the relationship between parity and premature delivery. Results: Data were collected from 1144 records of cervical length measurements of 738 pregnancies obtained from the HMO database. The study population consisted of 259 nulliparous women (35.1%), 451 multiparous women (61.1%), and 28 grand multiparous women (3.8%). The results from the multivariate analysis of the primary outcome showed that nulliparity was significantly associated with an increased risk of premature delivery, with a risk of 1.557 for nulliparous women compared to parous women. Conclusions: In this study, a statistically significant association was found between nulliparity and preterm birth among women with a short mid-trimester cervical length. Nulliparous women were found to have a higher risk of preterm birth in the current pregnancy compared to parous women. Further research is needed to understand the underlying mechanisms and to develop targeted interventions to reduce the risk of premature birth in this population. These findings highlight the need to consider nulliparity as a potential risk factor in the management of pregnancies with a shortened cervix.

SMFM Consult Series #70: Management of short cervix in individuals without a history of spontaneous preterm birth

Most deliveries before 34 weeks of gestation occur in individuals with no previous history of preterm birth. Midtrimester cervical length assessment using transvaginal ultrasound is one of the best clinical predictors of spontaneous preterm birth. This Consult provides guidance for the diagnosis and management of a short cervix in an individual without a history of preterm birth. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend that all cervical length measurements used to guide therapeutic recommendations be performed using a transvaginal approach and in accordance with standardized procedures as described by organizations such as the Perinatal Quality Foundation or the Fetal Medicine Foundation (GRADE 1C); (2) we recommend using a midtrimester cervical length of ≤25 mm to diagnose a short cervix in individuals with a singleton gestation and no previous history of spontaneous preterm birth (GRADE 1C); (3) we recommend that asymptomatic individuals with a singleton gestation and a transvaginal cervical length of ≤20 mm diagnosed before 24 weeks of gestation be prescribed vaginal progesterone to reduce the risk of preterm birth (GRADE 1A); (4) we recommend that treatment with vaginal progesterone be considered at a cervical length of 21 to 25 mm based on shared decision-making (GRADE 1B); (5) we recommend that 17-alpha hydroxyprogesterone caproate, including compounded formulations, not be prescribed for the treatment of a short cervix (GRADE 1B); (6) in individuals without a history of preterm birth who have a sonographic short cervix (10-25 mm), we recommend against cerclage placement in the absence of cervical dilation (GRADE 1B); (7) we recommend that cervical pessary not be placed for the prevention of preterm birth in individuals with a singleton gestation and a short cervix (GRADE 1B); and (8) we recommend against routine use of progesterone, pessary, or cerclage for the treatment of cervical shortening in twin gestations outside the context of a clinical trial (GRADE 1B).

Preterm birth in low-middle income Countries

Preterm birth (PTB), remains a major cause of significant morbidity and mortality world-wide with about 12-15million preterm births occurring every year. Although the overall trend is decreasing, this is mainly in high-income countries (HIC). The rate remains high in low-and middle-income countries (LMIC) varying on average between 10 and 12% compared to 9% in HIC. The pathogenesis of PTB is complex and multifactorial. Attempts to reduce rates that have focused on PTB as a single condition have in general been unsuccessful. However, more recent attempts to phenotype PTB have resulted in targeted preventative approaches which are yielding better results. Prevention (primary or secondary) is the only approach that has been shown to make a difference to rates of PTB. These include identifying risk factors pre-pregnancy and during pregnancy and instituting appropriate measures to address these. In LMIC, although some approaches that have been shown to be effective in some HIC are adaptable, there is a need to involve stakeholders at all levels in utilizing evidence preferrably generated in LMIC to implement strategies that are likely to reduce the rate of PTB. In this review, we focus on prevention and how to involve policy makers in the process of applying evidence into policy that would reduce PTB in LMIC.

Risk factors of early spontaneous preterm birth despite carrying a cervical pessary in singleton pregnancies with a short cervix: Development of a risk prediction model

Introduction

We aimed to identify the incidence and risk factors of spontaneous preterm birth in pessary carriers with singleton pregnancies and a short cervix in the mid-trimester of pregnancy.

Material and Methods

Patient data were obtained from the PECEP Trial. We analyzed singleton pregnancies in pessary carriers with a short cervix (≤25 mm) between 18 and 22 gestational weeks. Demographics and obstetric history were compared to identify risk factors for spontaneous preterm birth < 34 gestational weeks. Each demographic and obstetric variable was compared between spontaneous preterm birth < 34 and ≥ 34 weeks of gestation.Regression analysis was used to identify risk factors. A risk score model was generated using the odds ratio for significant factors. The risk score model and spontaneous preterm birth risk were assessed using the receiver operating characteristic curve. Perinatal outcomes were compared by risk score.

Results

Among 190 pregnant individuals, 12 (6.3%) had spontaneous preterm birth < 34 gestational weeks. In the bivariate analysis, statistically significant differences between those with and without spontaneous preterm birth were only observed for mean cervical length at diagnosis and mean cervical length after pessary placement. By multiple logistic regression analysis, maternal age (OR 0.818; 95% CI 0.69-0.97; P 0.020), cervical length at diagnosis (OR 0.560; 95% CI 0.43-0.73; P < 0.001) and smoking status (OR 7.276; 95% CI 1.02-51.80; P 0.048) remained significantly associated with spontaneous preterm birth.The ROC curve from the multiple logistic regression analysis, including cervical length, maternal age and smoking status, had an area under the curve (AUC) of 0.952 (P < 0.001). The ROC curve for the risk score model incorporating all three variables had an AUC of 0.864 (95% CI 0.77-0.96; P < 0.001). A high-risk score was predictive of spontaneous preterm birth with a sensitivity of 75%, specificity of 84%, positive predictive value of 24%, and negative predictive value of 98%.Women with a high-risk score had a significantly reduced latency to delivery and poorer neonatal outcomes than those with a low-risk score.

Conclusions

Patients at a high risk for spontaneous preterm birth despite pessary therapy may be identified using cervical length at diagnosis added to maternal age and smoking status.

Use and Impact of Pessary, Cerclage, and Progesterone for the Secondary Prevention of Preterm Birth: Data from the German Neonatal Network

BACKGROUND

To evaluate the use and effect of cervical stitch cerclage, pessary, and progesterone on pregnancy outcome in mothers of very low birth weight infants (VLBWI) born<32 weeks of gestation in the German Neonatal Network (GNN).

METHODS

The GNN is a population-based cohort study enrolling VLBWI since 2009. We included 575 neonates from 424 mothers into our analysis, who were born between 2015 and 2019, after prenatal intervention with cerclage, pessary, progesterone or a combination between 20/0 to 25/0 weeks of gestation to prevent preterm birth. Median intervention-to-birth interval was the primary endpoint.

RESULTS

231 of 424 pregnant women had a cerclage only (54.5%), 76 women a pessary only (17.9%), and 27 were prescribed progesterone only (15.3%). The most common combination treatment (>1 intervention group) was cerclage plus progesterone (n=27), followed by cerclage plus pessary (n=13). The median intervention-to-birth interval for the whole cohort was 24 days (IQR 19.0 days). The earlier the intervention was started, the longer the intervention-to-birth interval lasted: When started at 20 weeks, the interval was 34 days in contrast to 11.5 days, when started at 25 weeks. The >1 group was born at a significantly higher median GA with 27.0 weeks (IQR 2.9 weeks) and a higher median birth weight of 980 g (IQR 394 g) accordingly.

CONCLUSION

We propose that the earliest possible start of intervention leads to the most efficient pregnancy prolongation.

Universal cervical length screening and risk of spontaneous preterm birth: a systematic review and meta-analysis

OBJECTIVE

To evaluate the risk of spontaneous preterm birth with or without universal transvaginal ultrasound cervical length screening at the time of midtrimester scan.

DATA SOURCES

Medline, Embase, ClinicalTrials.gov, and Web of Science were systematically searched from the inception of the databases to November 12, 2023, using combinations of the relevant medical subject heading terms, key words, and word variants that were considered suitable for the topic.

STUDY ELIGIBILITY CRITERIA

Studies including individuals with singleton gestations at 16-25 weeks of gestation screened or not screened with universal transvaginal ultrasound cervical length screening were considered eligible. Primary outcome was spontaneous preterm birth <37 weeks; secondary outcomes were spontaneous preterm birth <34 and <32 weeks.

METHODS

Random effect head-to-head analyses were used to directly compare each outcome, expressing the results as summary odds ratio and relative 95% confidence interval. The quality of the included studies was independently assessed by 2 reviewers, using the Newcastle-Ottawa scale for cohort studies and the Cochrane risk-of-bias tool for randomized controlled studies. The study was registered on the prospective register of systematic reviews database (PROSPERO) (registration number: CRD42022385325).

RESULTS

Eight studies, including 447,864 pregnancies, were included in the meta-analysis (213,064 screened with transvaginal ultrasound cervical length and 234,800 unscreened). In the overall analysis, universal transvaginal ultrasound cervical length did not significantly decrease the spontaneous preterm birth rates <37 weeks (odds ratio, 0.92 [95% confidence interval, 0.84-1.01], P=.07) and <34 weeks (odds ratio, 0.87 [95% confidence interval, 0.73-1.04], P=.12), but was significantly associated with a lower risk of spontaneous preterm birth <32 weeks (odds ratio, 0.84 [95% confidence interval, 0.76-0.94], P=.002). Individuals without a prior spontaneous preterm birth had a significantly lower risk of spontaneous preterm birth <37 weeks (odds ratio, 0.88 [95% confidence interval, 0.79-0.97], P=.01) and a lower trend of spontaneous preterm birth <32 weeks (odds ratio, 0.82 [95% confidence interval, 0.66-1.01], P=.06) when screened with transvaginal ultrasound cervical length, compared with no screening.

CONCLUSION

Universal transvaginal ultrasound cervical length screening usually <24 weeks in singletons without a prior spontaneous preterm birth, is associated with a significant reduction in spontaneous preterm birth <37 weeks, compared with no screening.

Cerclage prevents ascending intrauterine infection in pregnant mice

BACKGROUND

The treatment for cervical insufficiency is cerclage surgery. Although cerclage is a common therapy for prevention of preterm birth, there is no consensus about its mechanism of efficacy. Previous investigators have hypothesized that cerclage prevents preterm birth by improving the cervical barrier to ascending infection. However, this hypothesis is difficult to study in human pregnancy.

OBJECTIVE

In a mouse model of ascending infection, we hypothesized that a cerclage improves the cervical barrier leading to decreased ascending intrauterine infection and inflammation. An abdominal cerclage was studied because a vaginal cerclage is not feasible in mice.

STUDY DESIGN

To perform an abdominal cerclage, laparotomy was performed on timed, pregnant C57BL/6 mice on gestational day 10 (E10). A 6-0 silk suture was placed around the cervix just below the junction of the 2 uterine horns. Sham controls received the same surgery, but no cerclage was placed. To track ascending infection nonpathogenic E coli K12 was genetically modified to express bioluminescence. On E15, bioluminescent E coli K12 (20 μL of 1×109 bacteria) was inoculated into the vagina. Whole-body bioluminescence imaging was performed 0.5 hours and 24 hours after inoculation. To assess intrauterine inflammation, pathogenic E coli K1 was used. On E15, bacterial inoculums of E coli K1 (20 μL of 1×104 bacteria) were vaginally administered. Samples of uterus, placenta, and fetal membranes were collected 24 hours after inoculation. Gene expression of inflammation-related proteins was compared between 3 groups: (1) sham control surgery + inoculation of phosphate-buffered saline (PBS), (2) sham control surgery + inoculation of E coli K1, and (3) cerclage surgery + inoculation of E coli K1.

RESULTS

Abdominal cerclage was well tolerated. No cases of preterm birth were seen following abdominal cerclage. Whole-body bioluminescent imaging performed 0.5 hours post inoculation showed a strong luminescence signal in the vaginal region of mice in both control and experimental groups indicating successful bacteria inoculation. Twenty-four hours after inoculation, bioluminescent signal was seen ascending into the uterine horns in all control mice. However, in mice with abdominal cerclages, no bioluminescent signal was seen after 24 hours. When the reproductive tissues were imaged separately in control mice, strong bioluminescence signal was detected in the placenta, fetal membranes, and uterus. Gene expression studies showed that cerclage significantly decreased the expression of inflammatory proteins induced by E coli K1 in the uterus, placenta, and fetal membranes.

CONCLUSION

In this mouse model of ascending intrauterine infection, abdominal cerclage prevented ascending infection of E coli. In addition, abdominal cerclage prevented expression of inflammatory cytokines in the uterus, placenta, and membranes of mice. The study provides evidence for a potential mechanism of cerclage success in human pregnancy.

Validating staging criteria for sonographic and physical examination for cervical changes at <24 weeks' gestation to predict preterm birth

BACKGROUND

Preterm birth represents a significant clinical challenge, and the ability to predict it effectively is a priority in obstetrics. The cervix undergoes specific changes during pregnancy, and staging these changes may offer a valuable predictive model for preterm birth, particularly among women with a midtrimester short cervical length.

OBJECTIVE

The study aimed to validate a proposed staging model for asymptomatic women with midtrimester short cervical length and to evaluate its potential for predicting preterm birth. The integration of cervical examination and inspection with cervical length measurement was a novel approach to be assessed.

STUDY DESIGN

This was a multicenter, retrospective cohort study that included 925 pregnant women with a singleton fetus and a midtrimester cervical length measurement of ≤25 mm. Cervical conditions were assessed using ultrasonography, a speculum, and a physical examination and were classified into 1 of 5 cervical stages to correlate with the likelihood of preterm birth. Statistical analyses included Kaplan-Meier survival analysis to illustrate the time-to-event characteristics across the 5 stages and density plot evaluation to visualize the distribution of the gestational ages within the stages.

RESULTS

The staging model included 5 stages based on cervical length, appearance, and dilatation. Among the 925 participants, 649 were classified as being stage 1, 245 as stage 2, 18 as stage 3, 10 as stage 4, and 3 as stage 5. The observed rates of preterm birth before 37 weeks for individuals classified in stages 1, 2, 3, 4, and 5 were 22.3%, 26.5%, 44.4%, 60%, and 66.7%, respectively (P=.005). The overall observed rates of preterm birth before 28, 32, 34, and 37 weeks' gestation were 5.5%, 9.9%, 12.2%, and 24.1%, respectively (P=.005).

CONCLUSION

This study validated the proposed staging criteria as an effective predictor of preterm birth caused by cervical insufficiency. The results demonstrate a significant increase in the preterm birth rate with advancing stage classification, indicating that the staging effectively stratified women based on their risk for preterm birth and highlighting the potential use for targeted interventions. Implementing these staging criteria can potentially improve the counseling and management of pregnant women at risk for preterm birth.

Reduction in cervical length after vaginal progesterone in women with short cervix is significantly associated with preterm delivery at ≤ 34 weeks and < 37 weeks of gestation

OBJECTIVE

To evaluate the association between changes in cervical length (CL) after vaginal progesterone treatment and preterm delivery (PTD).

METHODS

This was a retrospective cohort study that included 197 singleton pregnancies without (n = 178) and with (n = 19) a history of PTD which were found to have a short cervix (≤ 25 mm) between 18 + 0 and 23 + 6 weeks' gestation with a follow-up transvaginal CL measurement taken at least 1 week after vaginal progesterone treatment started. Receiver-operating-characteristics (ROC)-curve analysis was performed and three CL shortening patterns were evaluated: (1) ≥ 10% reduction; (2) ≥ 20% reduction; and (3) ≥ 5 mm reduction relative to the first CL measurement. The predictive performance of each CL reduction cut-off and its association with PTD ≤ 34 weeks and PTD < 37 weeks were evaluated.

RESULTS

Overall, the rate of PTD ≤ 34 weeks was 16.8% (33/197) and that of PTD < 37 weeks was 36.5% (72/197). The area under the ROC curve of cervical shortening expressed in % for predicting PTD ≤ 34 weeks and PTD < 37 weeks was 0.703 and 0.608, respectively. Cervical shortening was observed in 60/197 (30.5%) patients, with 49/60 (81.7%) women showing ≥ 10% reduction, 32/60 (53.3%) ≥ 20% reduction and 27/60 (45.0%) ≥ 5 mm reduction in CL. Sensitivity and specificity for PTD ≤ 34 weeks were, respectively, 48.5% and 79.9% for ≥ 10% reduction; 36.4% and 87.8% for ≥ 20% reduction; and 27.3% and 89.0% for ≥ 5 mm reduction in CL. For PTD < 37 weeks, sensitivity and specificity were, respectively, 36.1% and 81.6% for ≥ 10% reduction; 27.8% and 90.4% for ≥ 20% reduction; and 20.8% and 90.4% for ≥ 5 mm reduction in CL. The highest positive likelihood ratios for PTD ≤ 34 and < 37 weeks were for ≥ 20% CL reduction (2.98 (95% CI, 1.62-5.49) and 2.89 (95% CI, 1.52-5.57), respectively). Despite significant differences in sensitivity among the different cut-offs for cervical shortening, favoring the ≥ 10% reduction cut-off, a reduction of ≥ 20% in CL showed the strongest association with PTD ≤ 34 weeks (odds ratio (OR), 4.11 (95% CI, 1.75-9.62)) and < 37 weeks (OR, 3.62 (95% CI, 1.65-7.96)), as compared with a less pronounced reduction in CL.

CONCLUSIONS

In women with a short cervix treated with vaginal progesterone, a reduction in CL on a subsequent ultrasound scan can predict PTD ≤ 34 and < 37 weeks. A ≥ 20% reduction in CL had the highest positive likelihood ratio and strongest association with PTD ≤ 34 and < 37 weeks compared with ≥ 10% or ≥ 5 mm reduction. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Randomized trial of screening for preterm birth in low-risk women - the preterm birth screening study

BACKGROUND

Preterm birth is a major cause of perinatal morbidity and mortality. It is unclear whether the introduction of a universal transvaginal ultrasound cervical length screening program in women at low risk for preterm delivery is associated with a reduction in the frequency of preterm birth.

OBJECTIVE

To test the hypothesis that the introduction of a midtrimester universal transvaginal ultrasound cervical length screening program in asymptomatic singleton pregnancies without prior preterm delivery would reduce the rate of preterm birth at <37 weeks of gestation.

STUDY DESIGN

This study was a multicenter nonblinded randomized trial of screening of asymptomatic singleton pregnancies without prior spontaneous preterm birth, who were randomized to either cervical length screening program (ie, intervention group) or no screening (ie, control group). Participants were randomized at the time of their routine anatomy scan between 18 0/7 and 23 6/7 weeks of gestation. Women randomized in the screening group received cervical length measurement. Those who were found to have cervical length ≤25 mm were offered 200 mg vaginal progesterone daily along with cervical pessary. The primary outcome was preterm birth at <37 weeks. The risk of primary outcome was quantified by the relative risk with 95% confidence interval, and was based on the intention-to-screen principle.

RESULTS

A total of 1334 asymptomatic women with singleton pregnancies and without prior preterm birth, were included in the trial. Out of the 675 women randomized in the transvaginal ultrasound cervical length screening group, 13 (1.9%) were found to have transvaginal ultrasound cervical length ≤25 mm during the screening. Preterm birth at <37 weeks of gestation occurred in 48 women in the transvaginal ultrasound cervical length screening group (7.5%), and 54 women in the control group (8.7%) (relative risk, 0.86; 95% confidence interval, 0.59-1.25). Women randomized in the transvaginal ultrasound cervical length screening group had no significant differences in the incidence of preterm birth at less than 34, 32, 30, 28, and 24 weeks of gestation.

CONCLUSION

The introduction of a universal transvaginal ultrasound cervical length screening program at 18 0/6 to 23 6/7 weeks of gestation in singleton pregnancies without prior spontaneous preterm birth, with treatment for those with cervical length ≤25 mm, did not result in significant lower incidence of preterm delivery than the incidence without the screening program.

Prevention of spontaneous preterm delivery – an update on where we are today

Spontaneous preterm birth (delivery before 37 completed weeks) is the single most important cause of perinatal morbidity and mortality. The rate is increasing world-wide with a great disparity between low, middle and high income countries. It has been estimated that the cost of neonatal care for preterm babies is more than 4 times that of a term neonate admitted into the neonatal care. Furthermore, there are high costs associated with long-term morbidity in those who survive the neonatal period. Interventions to stop delivery once preterm labor starts are largely ineffective hence the best approach to reducing the rate and consequences is prevention. This is either primary (reducing or minimizing factors associated with preterm birth prior to and during pregnancy) or secondary - identification and amelioration (if possible) of factors in pregnancy that are associated with preterm labor. In the first category are optimizing maternal weight, promoting healthy nutrition, smoking cessation, birth spacing, avoidance of adolescent pregnancies and screening for and controlling various medical disorders as well as infections prior to pregnancy. Strategies in pregnancy, include early booking for prenatal care, screening and managing medical disorders and their complications, and identifying predisposing factors to preterm labor such as shortening of the cervix and timely instituting progesterone prophylaxis or cervical cerclage where appropriate. The use of biomarkers such as oncofetal fibronectin, placental alpha-macroglobulin-1 and IGFBP-1 where cervical screening is not available or to diagnosis PPROM would identify those that require close monitoring and allow the institution of antibiotics especially where infection is considered a predisposing factor. Irrespective of the approach to prevention, timing the administration of corticosteroids and where necessary tocolysis and magnesium sulfate are associated with an improved outcome. The role of genetics, infections and probiotics and how these emerging dimensions help in the diagnosis of preterm birth and consequently prevention are exciting and hopefully may identify sub-populations for targeted strategies.

Factors Associated with Spontaneous Preterm Birth after Ultrasound-Indicated Cerclage

Ultrasound-indicated cerclage (UIC) is recommended to prevent spontaneous preterm birth (sPTB) in women with a short cervix at mid-trimester and a history of PTB. We assessed the factors related to sPTB after UIC and determined the corresponding risks. This retrospective cohort study was conducted at a university hospital. UIC was performed between 15 and 26 weeks of gestation in women with a cervical length of <2.5 cm. Univariate and multivariate analyses were used to examine factors associated with sPTB after UIC. An earlier gestational age and shorter cervical length at UIC were associated with sPTB after UIC. While PTB history was not associated with an increased risk of sPTB, it did increase the risk of repeat cerclage after UIC. Higher levels of preoperative serum inflammatory markers and obesity significantly increased the risk of sPTB after UIC. These findings provide helpful guidance for patient counseling and management in predicting the delivery timing after UIC in women with a short cervix in the mid-trimester.

Cervical Cerclage vs. Pessary in Women with a Short Cervix on Ultrasound

PURPOSE

In the present study we sought to compare the efficacy of cervical pessary to that of cerclage in terms of reducing preterm birth rates among women with a short (<25 mm) or ultra-short (<15 and <10 mm) cervix during the ultrasonographic second-trimester assessment.

METHOD

We retrospectively searched the hospital records for singleton pregnancies diagnosed with cervical insufficiency during the second trimester of pregnancy. The McDonald cerclage using a 5mm Mersilene tape was used in all women. An Arabin pessary was used uniformly. In all cases 80 mg of vaginal progesterone gel were administered daily until 37 weeks of gestation.

RESULTS

Overall, 294 women (124 (42.2%) with a McDonald cerclage and 170 (57.8%) with placement of an Arabin pessary) were selected for analysis. Preterm birth rates <37 weeks were similar in both groups (C: 30/122 vs. P: 35:165, p=.581) as well as PTB <34 weeks (C: 16/122 vs. 15/150, p=.278). Admission to the NICU and need for CPAP were more prevalent in the cerclage group (p<.001). Analysis of cases with a cervix <15 mm and <10 mm indicated that preterm birth rates remained equal among the groups, while an increased risk of NICU admission was seen in cases with a cervical length <10 mm that were treated with cerclage.

DISCUSSION AND CONCLUSION

Cervical pessary may be an alternative to cervical cerclage for women with second-trimester cervical shortening and its effect may persist even among cases with an ultra-short cervix. Future randomized trials are needed to ascertain these findings.

Bioengineering and the cervix: The past, current, and future for addressing preterm birth

The uterine cervix plays two important but opposing roles during pregnancy - as a mechanical barrier that maintains the fetus for nine months and as a compliant structure that dilates to allow for the delivery of a baby. In some pregnancies, however, the cervix softens and dilates prematurely, leading to preterm birth. Bioengineers have addressed and continue to address the lack of reduction in preterm birth rates by developing novel technologies to diagnose, prevent, and understand premature cervical remodeling. This article highlights these existing and emerging technologies and concludes with open areas of research related to the cervix and preterm birth that bioengineers are currently well-positioned to address.

Reassessing Preterm Birth Prevention After the Withdrawal of 17-α Hydroxyprogesterone Caproate

The U.S. Food and Drug Administration has recently withdrawn approval for 17-α hydroxyprogesterone caproate for prevention of recurrent preterm birth, and recent studies have called into question benefits of the pessary in the setting of a short cervix. Obstetric health care professionals are once again left with limited remaining options for preterm birth prevention. This narrative review summarizes the best current evidence on the use of vaginal progesterone, low-dose aspirin, and cerclage for the prevention of preterm birth; attempts to distill possible lessons learned from studies of progesterone and pessary, as well as their implementation into practice; and highlights areas where inroads into preterm birth prevention may be possible outside of the progesterone-aspirin-cerclage paradigm.

Addition of cervical elastosonography to cervical length to predict preterm birth in pregnancy women with prior preterm birth: A preliminary prospective study

OBJECTIVES

To investigate the characteristics of cervical elastosonography in pregnancies and establish an ultrasound-based combing predictor for improving the prediction in pregnant women with prior-preterm birth who might ultimately undergo preterm birth (PTB).

MATERIALS AND METHODS

169 singleton pregnancies with prior-preterm birth were examined by cervical elastography from January to November of 2021. According to the ultrasound image and result of the following-up, the patients were separated into preterm groups and full-term groups with or without cerclage. There were five elastographic parameters: Elasticity Contrast Index (ECI), Cervical hard tissue Elasticity Ratio (CHR), External Cervical os Strain rate (ES), Closed Internal Cervical os Strain rate (CIS), CIS/ES ratio and CLmin. Multivariable logistic regression was used to screen out the most significant predictors. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the ability of prediction.

RESULTS

The PTB group without cerclage showed significantly softer cervix stiffness, while those with cerclage showed significantly harder. CHRmin with P < 0.05 in the univariate logistic regression analysis was screened as a more valuable cervical elastosonography parameter than other ones. The combination of CLmin and CHRmin in un-cerclage and integrating CHRmin, maternal age and pre-pregnancy BMI in cerclage presented good predictive value. The results of AUC were higher than CLmin, respectively (0.775 vs 0.734, 0.729 vs 0.548).

CONCLUSIONS

The addition of cervical elastography parameters (such as CHRmin) might improve the ability to predict preterm birth in pregnant women with previous preterm delivery, which was better than using CL alone.

How to screen the cervix and reduce the risk of spontaneous preterm birth in asymptomatic women without a prior preterm birth

Preterm birth (PTB) is a leading cause of perinatal morbidity and mortality globally. PTB rates have increased in South Korea despite reduction in birth rates. A history of PTB is a strong predictor of subsequent PTB and screening of cervical length between 16 0/7 weeks and 24 0/7 weeks of gestation is recommended in women with a singleton pregnancy and a prior spontaneous PTB. However, the prediction and prevention of spontaneous PTBs in women without a prior PTB remain a matter of debate. The scope of this review article comprises cervical screening and prevention strategies for PTB in asymptomatic women without a prior PTB, based on recent evidence and guidelines.

Cervical Cerclage: A Comprehensive Review of Major Guidelines

Importance

Cervical cerclage (CC) represents one of the few effective measures currently available for the prevention of preterm delivery caused by cervical insufficiency, thus contributing in the reduction of neonatal morbidity and mortality rates.

Objective

The aim of this study was to review and compare the most recently published major guidelines on the indications, contraindications, techniques, and timing of placing and removal of CC.

Evidence Acquisition

A descriptive review of guidelines from the American College of Obstetricians and Gynecologists (ACOG), the Royal College of Obstetricians and Gynaecologists (RCOG), the Society of Obstetricians and Gynaecologists of Canada (SOGC), and the International Federation of Gynecology and Obstetrics (FIGO) on CC was carried out.

Results

There is a consensus among the reviewed guidelines regarding the recommended techniques, the indications for rescue CC, the contraindications, as well as the optimal timing of CC placement and removal. All medical societies also agree that ultrasound-indicated CC is justified in women with history of prior spontaneous PTD or mid-trimester miscarriage and a short cervical length detected on ultrasound. In addition, after CC, serial sonographic measurement of the cervical length, bed rest, and routine use of antibiotics, tocolysis, and progesterone are unanimously discouraged. In case of established preterm labor, CC should be removed, according to ACOG, RCOG, and SOGC. Furthermore, RCOG and SOGC agree on the prerequisites that should be met before attempting CC. These 2 guidelines along with FIGO recommend history-indicated CC for women with 3 or more previous preterm deliveries and/or second trimester pregnancy miscarriages, whereas the ACOG suggests the use of CC in singleton pregnancies with 1 or more previous second trimester miscarriages related to painless cervical dilation or prior CC due to painless cervical dilation in the second trimester. The role of amniocentesis in ruling out intra-amniotic infection before rescue CC remains a matter of debate.

Conclusions

Cervical cerclage is an obstetric intervention used to prevent miscarriage and preterm delivery in women considered as high-risk for these common pregnancy complications. The development of universal international practice protocols for the placement of CC seems of paramount importance and will hopefully improve the outcomes of such pregnancies.

Preeclampsia and the Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is characterized by venous or arterial thrombosis and/or adverse pregnancy outcome in the presence of persistent laboratory evidence of antiphospholipid antibodies (aPLs). Preeclampsia complicates about 10-17% of pregnancies with APS. However, only early onset preeclampsia (<34 weeks of gestation) belongs to the clinical criteria of APS. The similarities in the pathophysiology of early onset preeclampsia and APS emphasize an association of these two syndromes. Overall, both are the result of a defective trophoblast invasion and decidual transformation at early gestation. Women with APS are at increased risk for prematurity; the reasons are mostly iatrogenic due to placental dysfunction, such as preeclampsia or FGR. Interestingly, women with APS have also an increased risk for preterm delivery, even in the absence of FGR and preeclampsia, and therefore it is not indicated but spontaneous. The basic treatment of APS in pregnancy is low-dose aspirin and low-molecular-weight heparin. Nevertheless, up to 20-30% of women develop complications at early and late gestation, despite basic treatment. Several additional treatment options have been proposed, with hydroxychloroquine (HCQ) being one of the most efficient. Additionally, nutritional interventions, such as intake of vitamin D, have shown promising beneficial effects. Curcumin, due to its antioxidant and anti-inflammatory properties, might be considered as an additional intervention as well.

Cervical cerclage for prevention of preterm birth and adverse perinatal outcome in twin pregnancies with short cervical length or cervical dilatation: A systematic review and meta-analysis

BACKGROUND

The optimal approach to prevent preterm birth (PTB) in twins has not been fully established yet. Recent evidence suggests that placement of cervical cerclage in twin pregnancies with short cervical length at ultrasound or cervical dilatation at physical examination might be associated with a reduced risk of PTB. However, such evidence is based mainly on small studies thus questioning the robustness of these findings. The aim of this systematic review was to determine the role of cervical cerclage in preventing PTB and adverse maternal or perinatal outcomes in twin pregnancies.

METHODS AND FINDINGS

Key databases searched and date of last search: MEDLINE, Embase, and CINAHL were searched electronically on 20 April 2023. Eligibility criteria: Inclusion criteria were observational studies assessing the risk of PTB among twin pregnancies undergoing cerclage versus no cerclage and randomized trials in which twin pregnancies were allocated to cerclage for the prevention of PTB or to a control group (e.g., placebo or treatment as usual). The primary outcome was PTB <34 weeks of gestation. The secondary outcomes were PTB <37, 32, 28, 24 weeks of gestation, gestational age at birth, the interval between diagnosis and birth, preterm prelabor rupture of the membranes (pPROM), chorioamnionitis, perinatal loss, and perinatal morbidity. Subgroup analyses according to the indication for cerclage (short cervical length or cervical dilatation) were also performed. Risk of bias assessment: The risk of bias of the included randomized controlled trials (RCTs) was assessed using the Revised Cochrane risk-of-bias tool for randomized trials, while that of the observational studies using the Newcastle-Ottawa scale (NOS). Statistical analysis: Summary risk ratios (RRs) of the likelihood of detecting each categorical outcome in exposed versus unexposed women, and (b) summary mean differences (MDs) between exposed and unexposed women (for each continuous outcome), with their 95% confidence intervals (CIs) were computed using head-to-head meta-analyses. Synthesis of the results: Eighteen studies (1,465 twin pregnancies) were included. Placement of cervical cerclage in women with a twin pregnancy with a short cervix at ultrasound or cervical dilatation at physical examination was associated with a reduced risk of PTB <34 weeks of gestation (RR: 0.73, 95% CI [0.59, 0.91], p = 0.005 corresponding to a 16% difference in the absolute risk, AR), <32 (RR: 0.69, 95% CI [0.57, 0.84], p < 0.001; AR: 16.92%), <28 (RR: 0.54, 95% [CI 0.43, 0.67], 0.001; AR: 18.29%), and <24 (RR: 0.48, 95% CI [0.23, 0.97], p = 0.04; AR: 15.57%) weeks of gestation and a prolonged gestational age at birth (MD: 2.32 weeks, 95% [CI 0.99, 3.66], p < 0.001). Cerclage in twin pregnancy with short cervical length or cervical dilatation was also associated with a reduced risk of perinatal loss (RR: 0.38, 95% CI [0.25, 0.60], p < 0.001; AR: 19.62%) and composite adverse outcome (RR: 0.69, 95% CI [0.53, 0.90], p = 0.007; AR: 11.75%). Cervical cerclage was associated with a reduced risk of PTB <34 weeks both in women with cervical length <15 mm (RR: 0.74, 95% CI [0.58, 0.95], p = 0.02; AR: 29.17%) and in those with cervical dilatation (RR: 0.68, 95% CI [0.57, 0.80], p < 0.001; AR: 35.02%). The association between cerclage and prevention of PTB and adverse perinatal outcomes was exclusively due to the inclusion of observational studies. The quality of retrieved evidence at GRADE assessment was low.

CONCLUSIONS

Emergency cerclage for cervical dilation or short cervical length <15 mm may be potentially associated with a reduction in PTB and improved perinatal outcomes. However, these findings are mainly based upon observational studies and require confirmation in large and adequately powered RCTs.

Delayed interval delivery in a quadruplet pregnancy: a case report and literature review

BACKGROUND

As the rate of multiple pregnancies increases, delayed interval delivery (DID) is increasingly being implemented to improve perinatal outcomes. But there are no international guidelines for DID in multiple pregnancies. We report a case of DID in a quadruplet pregnancy and review the relevant literature to summarize the management of DID in multiple pregnancies.

CASE PRESENTATION

A 22-year-old woman, 22 2/7 weeks' gestation, with quadruplets, was admitted to the hospital for a first cervical cerclage due to cervical dilation. Twenty-five days later, it was found that the cervix was dilated again, so after removing the cervical cerclage, the first quadruplet was delivered vaginally (25 6/7 weeks), and a second cervical cerclage was performed. Four days later, due to re-dilation of the cervix, after removal of the cervical cerclage, the second quadruplet was delivered vaginally (26 3/7 weeks), followed by a third cervical cerclage. Six days later, the pregnancy was terminated by cesarean section due to fetal distress, and the third and fourth quadruplets were delivered (27 2/7 weeks). The patient had no postoperative complications, and all four infants were treated in the neonatal intensive care unit and discharged successfully.

CONCLUSION

This case emphasizes that comprehensive management of delayed interval delivery can improve perinatal outcomes in multiple pregnancies, including anti-infection, tocolytic therapy, practice to promote fetal lung, and cervical cerclage.

Incidentally Found Midtrimester Shortened Cervical Length: Practice Patterns among American Maternal-Fetal Medicine Specialists

OBJECTIVE

The management of incidentally found short cervical length (CL) without prior spontaneous preterm birth (PTB) can vary. While most agree on starting vaginal progesterone, management after CL shortens <10 mm varies. The purpose of this study was to elucidate current practice patterns amongst maternal-fetal medicine (MFM) specialists.

STUDY DESIGN

We conducted an online survey of MFM attending physicians and fellows in the United States from May 2019 to April 2020. The primary outcome was management of varying CL based on gestational age. Variations in management were assessed descriptively.

RESULTS

There were 236 respondents out of 400 eligible surveyed, with a response rate of 59.2%. Universal CL screening was reported by 93.6% (49.6% abdominal and 44.1% transvaginal). Management of short CL varied based on CL measurement, rather than gestational age at presentation. At CL <10 mm, management included cerclage (17.4-18.7%), vaginal progesterone (41.3-41.7%), or cerclage plus vaginal progesterone (43.4%). Between CL of 10 to 20 mm, the majority (77.4-91.9%) would start vaginal progesterone. At CL 21 to 25 mm, management varied between expectant management (45.5-48.5%) or vaginal progesterone (51.1-52.8%). Suture material used was ethylene terephthalate (47.4%) or polypropelene (31.2). Preoperative antibiotic use was reported by 22.3%, while 45.5% used them only if the amniotic membranes were exposed, and 32.2% reported no antibiotic use. Postoperative tocolytic use varied with 19.3% reporting no use, 32.6% using it always, 8.2% only after significant cervical manipulation, 22.7% after the patient is experiencing symptoms, and 17.6% using it only if the cervix is dilated on exam. After cerclage placement, 44.5% continued CL surveillance.

CONCLUSION

Substantial differences of opinion exist among MFM physicians regarding management of incidentally found short CL in patients without history of PTB. The differences in responses obtained highlight the need for evidence-based guidelines for managing this clinical scenario.

KEY POINTS

· There is lack of consensus on the management of incidentally found shortened CL.. · The purpose of this study was to elucidate current trends in CL screening and management.. · Substantial differences of opinion exist regarding management of incidentally found short CL..

Preterm labor with and without chorioamnionitis is associated with activation of myometrial inflammatory networks: a comprehensive transcriptomic analysis

BACKGROUND

The onset of preterm labor is associated with inflammation. Previous studies suggested that this is distinct from the inflammation observed during term labor. Our previous work on 44 genes differentially expressed in myometria in term labor demonstrated a different pattern of gene expression from that observed in preterm laboring and nonlaboring myometria. We found increased expression of inflammatory genes in preterm labor associated with chorioamnionitis, but in the absence of chorioamnionitis observed no difference in gene expression in preterm myometria regardless of laboring status, suggesting that preterm labor is associated with different myometrial genes or signals originating from outside the myometrium. Given that a small subset of genes were assessed, this study aimed to use RNA sequencing and bioinformatics to assess the myometrial transcriptome during preterm labor in the presence and absence of chorioamnionitis.

OBJECTIVE

This study aimed to comprehensively determine protein-coding transcriptomic differences between preterm nonlaboring and preterm laboring myometria with and without chorioamnionitis.

STUDY DESIGN

Myometria were collected at cesarean delivery from preterm patients not in labor (n=16) and preterm patients in labor with chorioamnionitis (n=8) or without chorioamnionitis (n=6). Extracted RNA from myometrial tissue was prepared and sequenced using Illumina NovaSeq. Gene expression was quantified by mapping the sequence reads to the human reference genome (hg38). Differential gene expression analysis, gene set enrichment analysis, and weighted gene coexpression network analysis were used to comprehensively interrogate transcriptomic differences and their associated biology.

RESULTS

Differential gene expression analysis comparing preterm patients in labor with chorioamnionitis with preterm patients not in labor identified 931 differentially expressed genes, whereas comparing preterm patients in labor without chorioamnionitis with preterm patients not in labor identified no statistically significant gene expression changes. In contrast, gene set enrichment analysis and weighted gene coexpression network analysis demonstrated that preterm labor with and without chorioamnionitis was associated with enrichment of pathways involved in activation of the innate immune system and inflammation, and activation of G protein-coupled receptors. Key genes identified included chemotactic CYP4F3, CXCL8, DOCK2, and IRF1 in preterm labor with chorioamnionitis and CYP4F3, FCAR, CHUK, and IL13RA2 in preterm labor without chorioamnionitis. There was marked overlap in the pathways enriched in both preterm labor subtypes.

CONCLUSION

Differential gene expression analysis demonstrated that myometria from preterm patients in labor without chorioamnionitis and preterm patients not in labor were transcriptionally similar, whereas the presence of chorioamnionitis was associated with marked gene changes. In contrast, comprehensive bioinformatic analysis indicated that preterm labor with or without chorioamnionitis was associated with innate immune activation. All causes of preterm labor were associated with activation of the innate immune system, but this was more marked in the presence of chorioamnionitis. These data suggest that anti-inflammatory therapy may be relevant in managing preterm labor of all etiologies.

Progesterone, cerclage, pessary, or acetylsalicylic acid for prevention of preterm birth in singleton and multifetal pregnancies - A systematic review and meta-analyses

Background

Preterm birth is the leading cause of childhood mortality and morbidity. We aimed to provide a comprehensive systematic review on randomized controlled trials (RCTs) on progesterone, cerclage, pessary, and acetylsalicylic acid (ASA) to prevent preterm birth in asymptomatic women with singleton pregnancies defined as risk of preterm birth and multifetal pregnancies.

Methods

Six databases (including PubMed, Embase, Medline, the Cochrane Library) were searched up to February 2022. RCTs published in English or Scandinavian languages were included through a consensus process. Abstracts and duplicates were excluded. The trials were critically appraised by pairs of reviewers. The Cochrane risk-of-bias tool was used for risk of bias assessment. Predefined outcomes including preterm birth, perinatal/neonatal/maternal mortality and morbidity, were pooled in meta-analyses using RevMan 5.4, stratified for high and low risk of bias trials. The certainty of evidence was assessed using the GRADE approach. The systematic review followed the PRISMA guideline.

Results

The search identified 2,309 articles, of which 87 were included in the assessment: 71 original RCTs and 16 secondary publications with 23,886 women and 32,893 offspring. Conclusions were based solely on trials with low risk of bias (n = 50).Singleton pregnancies: Progesterone compared with placebo, reduced the risk of preterm birth <37 gestational weeks: 26.8% vs. 30.2% (Risk Ratio [RR] 0.82 [95% Confidence Interval [CI] 0.71 to 0.95]) (high certainty of evidence, 14 trials) thereby reducing neonatal mortality and respiratory distress syndrome. Cerclage probably reduced the risk of preterm birth <37 gestational weeks: 29.0% vs. 37.6% (RR 0.78 [95% CI 0.69 to 0.88]) (moderate certainty of evidence, four open trials). In addition, perinatal mortality may be reduced by cerclage. Pessary did not demonstrate any overall effect. ASA did not affect any outcome, but evidence was based on one underpowered study.Multifetal pregnancies: The effect of progesterone, cerclage, or pessary was minimal, if any. No study supported improved long-term outcome of the children.

Conclusion

Progesterone and probably also cerclage have a protective effect against preterm birth in asymptomatic women with a singleton pregnancy at risk of preterm birth. Further trials of ASA are needed. Prevention of preterm birth requires screening programs to identify women at risk of preterm birth.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021234946].

GRADE Use in Evidence Syntheses Published in High-Impact-Factor Gynecology and Obstetrics Journals: A Methodological Survey

Objective: To identify and describe the certainty of evidence of gynecology and obstetrics systematic reviews (SRs) using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Method: Database searches of SRs using GRADE, published between 1 January 2016 to 31 December 2020, in the 10 "gynecology and obstetrics" journals with the highest impact factor, according to the Journal Citation Report 2019. Selected studies included those SRs using the GRADE approach, used to determine the certainty of evidence. Results: Out of 952 SRs, ninety-six SRs of randomized control trials (RCTs) and/or nonrandomized studies (NRSs) used GRADE. Sixty-seven SRs (7.04%) rated the certainty of evidence for specific outcomes. In total, we identified 946 certainty of evidence outcome ratings (n = 614 RCT ratings), ranging from very-low (42.28%) to low (28.44%), moderate (17.65%), and high (11.63%). High and very low certainty of evidence ratings accounted for 2.16% and 71.60% in the SRs of NRSs, respectively, compared with 16.78% and 26.55% in the SRs of RCTs. In the SRs of RCTs and NRSs, certainty of evidence was mainly downgraded due to imprecision and bias risks. Conclusions: More attention needs to be paid to strengthening GRADE acceptance and building knowledge of GRADE methods in gynecology and obstetrics evidence synthesis.

Prevention of Preterm Birth by Cervical Pessary Combined with Vaginal Progesterone: a Systematic Review and Meta-analysis with Trial Sequential Analysis

This study was to assess the effectiveness of cervical pessary combined with vaginal progesterone for the prevention of preterm birth (PTB). Ten studies about singleton [five randomized controlled trials (RCTs), vs vaginal progesterone; four cohorts, vs vaginal progesterone; two cohorts, vs cervical cerclage + vaginal progesterone] and two cohort studies about multiple pregnancies (vs vaginal progesterone) were included after searching electronic databases. For singleton pregnancies, the meta-analysis of three non-RCTs [relative risk (RR) = 0.41, p = 0.001] or total trials in non-Asian country (RR = 0.56, p = 0.03) revealed that compared with vaginal progesterone alone, cervical pessary + vaginal progesterone treatment had significant effectiveness on preventing PTB < 34 weeks, but not for five RCTs; meta-analysis of two trials showed that cervical pessary + vaginal progesterone had no significant prevention effects of PTB compared with cervical cerclage + vaginal progesterone. For multiple pregnancies, meta-analysis of two trials showed that compared with vaginal progesterone, cervical pessary + vaginal progesterone treatment increased neonatal birth weight (standardized mean difference = 0.50, p = 0.01). Trial sequential analysis implied additional studies were required. Four studies vs other controls (pessary, three-combined, tocolysis, conservative or no treatment; one study, each) were selected for systematic review. In conclusion, cervical pessary combined with vaginal progesterone may be safe and effective to prevent PTB in singleton pregnancies and increase neonatal birth weight in the multiple pregnancies compared with vaginal progesterone alone.

Proposed staging criteria for sonographic and physical exam for cervical changes at <24 weeks gestation to predict preterm birth

Asymptomatic cervical changes, such as cervical length shortening and dilation, which often occur before spontaneous preterm birth, have been described well in singleton pregnancies with or without history of preterm birth. The current screening strategies available to identify patients at increased risk of spontaneous preterm birth include use of transvaginal ultrasound for cervical length assessment and for detection of a short cervical length (≤25 mm) before 24 weeks of gestation. Whether an additional evaluation of the cervix (ie, via speculum or manual exam) is indicated is often pondered by clinicians and may depend on how short the cervical length is and if there is a history of preterm birth. Based on expert opinion, we developed a novel staging system of asymptomatic cervical changes including the following: cervical length measurement, cervical and membrane appearance on speculum exam, and cervical dilation by manual exam. This staging system, if proven accurate, may aid in standardizing definitions for purposes of patient prognosis, evaluation of intervention efficacy, and clinical management.

Relationship of Amniotic Fluid Sludge and Short Cervix With a High Rate of Preterm Birth in Women After Cervical Cerclage

OBJECTIVE

We aims to determine the relationship of amniotic fluid sludge (AFS) and/or short cervical length (CL, ≤25 mm) with a high rate of preterm birth in women after cervical cerclage.

METHODS

A retrospective cohort study was conducted among singleton pregnancies after cervical cerclage between January 2018 and December 2021. A total of 296 patients who underwent transvaginal ultrasound to evaluate CL and the presence of AFS within 2 weeks after cerclage were included. Pregnancy outcome after cerclage was analyzed in accordance with the presence of AFS and CL ≤25 mm.

RESULTS

In patients with cerclage, AFS was an independent risk factor for preterm birth at <28 and <36 weeks but not for preterm birth at <32 weeks, and CL ≤25 mm was an independent risk factor for preterm birth at <28, <32, and <36 weeks. The Kaplan-Meier analysis showed that the association between the presence of AFS and short gestational age at delivery was statistically significant in women with CL ≤25 mm (log rank test, P = .000). The Cox regression analysis showed that these results remained significant after adjusting for confounding factors (P = .000). The negative linear relationships between AFS and CL (R = -0.454, P < .001) also explained the outcome.

CONCLUSIONS

AFS and short cervix have a direct effect on pregnancies after cerclage. Mid-trimester AFS can become a supplementary ultrasound index for detecting preterm birth after cerclage in pregnant women with a short cervix.

Identification of risk factors for incident cervical insufficiency in nulliparous and parous women: a population-based case-control study

BACKGROUND

Cervical insufficiency is one of the underlying causes of late miscarriage and preterm birth. Although many risk factors have been identified, the relative magnitude of their association with risk in nulliparous versus parous women has not been well demonstrated, especially for incident cervical insufficiency (ICI). The aim of this study was to investigate and compare the magnitude of the association of ICI with predictive factors in nulliparous and parous women, and to further investigate various aspects of obstetric history for parous women.

METHODS

Pregnant women with a first diagnosis of cervical insufficiency were compared to a random sample of control pregnancies from women with no diagnosis by using Swedish national health registers. Demographic, reproductive, and pregnancy-specific factors were compared in case and control pregnancies, and relative risks presented as odds ratios (OR), stratified by nulliparous/parous. Independent associations with ICI were estimated from multivariable logistic regression. Associations with obstetric history were further estimated for multiparous women.

RESULTS

A total of 759 nulliparous ICI cases and 1498 parous cases were identified during the study period. Multifetal gestation had a strong positive association with ICI in both groups, but of much larger magnitude for nulliparous women. The number of previous miscarriages was also a much stronger predictor of risk in nulliparous women, especially for multifetal pregnancies. History of preterm delivery (<37 weeks' gestation) was an independent predictor for parous women, and for those whose most recent delivery was preterm, the association with ICI increased with each additional week of prematurity. A previous delivery with prolonged second stage of labor or delivery of a very large infant were both inversely associated with risk of ICI in the current pregnancy.

CONCLUSIONS

The differences in importance of predictive risk factors for incident cervical insufficiency in nulliparous and parous women can help resolve some of the inconsistencies in the literature to date regarding factors that are useful for risk prediction. Stratifying on parity can inform more targeted surveillance of at-risk pregnancies, enable the two groups of women to be better informed of their risks, and eventually inform screening and intervention efforts.

Cervical cerclage for prevention of preterm birth: the results from A 20-year cohort

Cerclages can be used to prevent preterm birth, although their effectiveness and safety is disputed. We aimed to describe obstetric outcomes after cerclage procedures. We included 156 singleton pregnancies and six multiple pregnancies. In singleton pregnancies with history-indicated, short cervix-indicated and emergency cerclages, respectively 84.6, 76.5 and 43.8% resulted in late preterm or term deliveries. In singletons, the following complications were reported: excessive bleeding in one emergency cerclage procedure and three re-cerclage procedures in the history-indicated cerclage group. No perioperative rupture of membranes occurred in singletons. When comparing results of experienced and less-experienced gynaecologists, a remarkably smaller take home child rate was observed for singletons treated by less-experienced gynaecologists: 90.7% and 94.4% for the two experienced gynaecologist as compared to 85.0% for the group of less-experienced gynaecologists. In conclusion, cerclages in singletons result in few cerclage-associated complications and a high take home child rate, when performed by experienced gynaecologists. Impact statementWhat is already known on this subject? Prematurity is the leading cause of perinatal and neonatal mortality and morbidity worldwide. Cervical cerclages can be used to prevent preterm birth, although their effectiveness and safety is disputed.What the results of this study add? In our cohort study, singleton pregnancies with cerclages seem to have satisfactory obstetric outcomes. We found a very low prevalence of cerclage-associated complications in singleton pregnancies, for both history-indicated, short cervix-indicated and emergency cerclages. Additionally, take home child rates in singleton pregnancies were remarkably higher when cerclage procedures were performed by experienced gynaecologists, compared to less experienced gynaecologists.What the implications are of these findings for clinical practice and/or further research? Based on the observed difference in take home child rates, we advise all cerclage procedures to be performed by experienced gynaecologists only. This may mean that women with an indication for cerclage will be referred to a more experienced colleague, either in the same, or in another hospital. To ensure treatment by an experienced gynaecologist, simulation-based training could also provide a solution.

Outcomes following Placement and Removal of Transvaginal Cerclage in at Risk Pregnancies: A Single Center Experience

Objective

The objective of this study was to estimate the time between removal of cerclage and delivery, stratified by indication for cerclage placement (elective or non-elective). Additionally, delivery within 72 hours after cerclage removal was compared between elective and non-elective cerclage placement, as well as between ultrasound-indicated and physical examination-indicated cerclage placement.

Design

A single-center retrospective cohort study. Participants/Materials, Setting, and Methods. Clinical information of 72 pregnant women who underwent transvaginal cerclage over a 4-year period was obtained. Comparisons were made between elective (history-indicated) and non-elective (ultrasound or physical examination-indicated) cerclage placement. Comparisons were also made between physical examination-indicated and ultrasound-indicated cerclage.

Results

Compared to those who had a non-elective cerclage, women undergoing elective cerclage were more likely to have history of cervical treatment (44% vs. 15%, p = 0.02), and spontaneous preterm delivery (92% vs. 61%, p = 0.003). There was no difference in the rate of delivery ≤72 hours following cerclage removal between women who had elective cerclage and those who had non-elective cerclage (46% vs. 58%, p = 0.47). Women who had an elective cerclage were more likely to have elective cerclage removal ≥36 weeks (71.8% vs. 39.4%, p = 0.01), compared to those who had undergone non-elective cerclage. The rate of delivery ≤72 hours following removal of cerclage was greater in women who had a physical examination-indicated cerclage compared to women who had ultrasound-indicated cerclage (80% vs. 39%, p = 0.04). Among women who had an elective cerclage, there was no difference in the rate of delivery at ≤72 hours between those who had elective cerclage removal at 36 weeks compared to those electively removed at 37 weeks (31% vs. 58%, p = 0.30). No complications such as fetal demise, iatrogenic amniotic membrane rupture, hemorrhage, or cervical laceration were reported within this cohort.

Conclusion

Cerclage indication should be considered prior to scheduling elective cerclage removal. Women who had an elective cerclage are most likely to get it electively removed at 36 weeks compared to their counterparts who had a non-elective cerclage. Furthermore, women who had a physical examination-indicated cerclage are most likely to deliver within 72 hours of cerclage removal.

The amniotic fluid proteome predicts imminent preterm delivery in asymptomatic women with a short cervix

Preterm birth, the leading cause of perinatal morbidity and mortality, is associated with increased risk of short- and long-term adverse outcomes. For women identified as at risk for preterm birth attributable to a sonographic short cervix, the determination of imminent delivery is crucial for patient management. The current study aimed to identify amniotic fluid (AF) proteins that could predict imminent delivery in asymptomatic patients with a short cervix. This retrospective cohort study included women enrolled between May 2002 and September 2015 who were diagnosed with a sonographic short cervix (< 25 mm) at 16-32 weeks of gestation. Amniocenteses were performed to exclude intra-amniotic infection; none of the women included had clinical signs of infection or labor at the time of amniocentesis. An aptamer-based multiplex platform was used to profile 1310 AF proteins, and the differential protein abundance between women who delivered within two weeks from amniocentesis, and those who did not, was determined. The analysis included adjustment for quantitative cervical length and control of the false-positive rate at 10%. The area under the receiver operating characteristic curve was calculated to determine whether protein abundance in combination with cervical length improved the prediction of imminent preterm delivery as compared to cervical length alone. Of the 1,310 proteins profiled in AF, 17 were differentially abundant in women destined to deliver within two weeks of amniocentesis independently of the cervical length (adjusted p-value < 0.10). The decreased abundance of SNAP25 and the increased abundance of GPI, PTPN11, OLR1, ENO1, GAPDH, CHI3L1, RETN, CSF3, LCN2, CXCL1, CXCL8, PGLYRP1, LDHB, IL6, MMP8, and PRTN3 were associated with an increased risk of imminent delivery (odds ratio > 1.5 for each). The sensitivity at a 10% false-positive rate for the prediction of imminent delivery by a quantitative cervical length alone was 38%, yet it increased to 79% when combined with the abundance of four AF proteins (CXCL8, SNAP25, PTPN11, and MMP8). Neutrophil-mediated immunity, neutrophil activation, granulocyte activation, myeloid leukocyte activation, and myeloid leukocyte-mediated immunity were biological processes impacted by protein dysregulation in women destined to deliver within two weeks of diagnosis. The combination of AF protein abundance and quantitative cervical length improves prediction of the timing of delivery compared to cervical length alone, among women with a sonographic short cervix.

Abnormal vaginal flora and spontaneous preterm birth in high-risk singleton pregnancies with cervical cerclage

OBJECTIVE

To investigate abnormal vaginal and suture-based bacterial flora for associations with spontaneous preterm birth in high-risk singleton pregnancies with an ultrasound-indicated or emergency cervical cerclage.

MATERIALS AND METHODS

A retrospective study of 196 singleton pregnancies with an ultrasound-indicated or emergency cerclage at the Royal Women's Hospital, Australia, from 2004 to 2018. High vaginal swabs were collected regularly between 14 and 26 weeks' gestation, including pre- and post-cerclage insertion, and sent for microscopy and culture. Cervical suture was cultured upon removal. Primary outcomes were spontaneous preterm birth <37, <34 and <30 weeks.

RESULTS

43.4% (85/196) of women delivered preterm. The acquisition and persistence of vaginal Escherichia coli following cerclage insertion were independently associated with spontaneous preterm birth <37 weeks (p = .0225, p = .0477). Escherichia coli growth from the cervical suture upon removal was associated with spontaneous preterm birth <34 weeks (p = .0458). The acquisition of vaginal mixed anaerobes post-cerclage was independently associated with spontaneous preterm birth <34 weeks (p = .0480).

CONCLUSION

For singleton pregnancies with an ultrasound-indicated or emergency cerclage, the presence of vaginal or suture-based Escherichia coli following cerclage insertion yields increased risk of cerclage failure and spontaneous preterm birth.

Interventions for the prevention of spontaneous preterm birth: a scoping review of systematic reviews

BACKGROUND

Globally, 11% of babies are born preterm each year. Preterm birth (PTB) is a leading cause of neonatal death and under-five mortality and morbidity, with lifelong sequelae in those who survive. PTB disproportionately impacts low/middle-income countries (LMICs) where the burden is highest.

OBJECTIVES

This scoping review sought to the evidence for interventions that reduce the risk of PTB, focusing on the evidence from LMICs and describing how context is considered in evidence synthesis.

DESIGN

We conducted a scoping review, to describe this wide topic area. We searched five electronic databases (2009-2020) and contacted experts to identify relevant systematic reviews of interventions to reduce the risk of PTB. We included published systematic reviews that examined the effectiveness of interventions and their effect on reducing the risk of PTB. Data were extracted and is described narratively.

RESULTS

139 published systematic reviews were included in the review. Interventions were categorised as primary or secondary. The interventions where the results showed a greater effect size and consistency across review findings included treatment of syphilis and vaginal candidiasis, vitamin D supplementation and cervical cerclage. Included in the 139 reviews were 1372 unique primary source studies. 28% primary studies were undertaken in LMIC contexts and only 4.5% undertaken in a low-income country (LIC) Only 10.8% of the reviews sought to explore the impact of context on findings, and 19.4% reviews did not report the settings or the primary studies.

CONCLUSION

This scoping review highlights the lack of research evidence derived from contexts where the burden of PTB globally is greatest. The lack of rigour in addressing contextual applicability within systematic review methods is also highlighted. This presents a risk of inappropriate and unsafe recommendations for practice within these contexts. It also highlights a need for primary research, developing and testing interventions in LIC settings.