Evaluation of effectiveness of prophylactic cerclage of a short cervix according to interleukin-8 in cervical mucus

Emergency cerclage outcomes for bulging fetal membranes: a single-center retrospective study

PURPOSE

This study aimed to investigate the usefulness of emergency cerclage for pregnant women with bulging fetal membranes, as indicated by our original noninvasive clinical scoring system.

METHODS

This was a retrospective study of pregnant women who underwent emergency cerclage for bulging fetal membranes within 28 weeks. The primary outcome was the continuation of pregnancy at 34 gestational weeks in singleton pregnancies and 32 gestational weeks in twin pregnancies. The secondary outcomes were the interval from cerclage to delivery, neonatal mortality, and morbidity. To determine surgical indication, we used the original clinical scoring system comprising cervical shortening or dilation degree and uterine contraction levels.

RESULTS

128 women were included in this study (112 singleton pregnancies and 16 twin pregnancies). The continuation of pregnancy rate as the primary outcome (Cerclage Success group) was 78.6% in singleton pregnancies and 75% in twin pregnancies. The median interval between cerclage and delivery was 94 days in singleton pregnancies and 78 days in twin pregnancies. Approximately 85% of the babies weighed ≥ 1500 g at birth. Neonatal mortality occurred in only one case, and nine singletons in the Cerclage Failure group had severe neonatal morbidities. According to multivariate analysis of prognostic factors in the Cerclage Failure group, only the serum C-reactive protein level at 1 week postoperatively was an independent prognostic factor (odds ratio: 9.75; 95% confidence interval: 2.99-31.8; p < 0.01).

CONCLUSION

Emergency cerclage, performed under the indications of our original noninvasive clinical scoring system, led to favorable outcomes.

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.

The potential presence of infection may be indicated through non-invasive prediction of procalcitonin and C-reactive protein levels within the initial three days after cervical cerclage: a retrospective case-control study

PURPOSE

To identify which non-invasive infection indicators could better predict post-cervical cerclage (CC) infections, and on which days after CC infection indicators should be closely monitored.

METHODS

The retrospective, single-center study included 619 single-pregnancy patients from January 2021 to December 2022. Patients were categorized into infected and uninfected groups based on physicians' judgments of post-CC infections. Registered information included patient characteristics, cervical insufficiency history, gestational age at CC, surgical method (McDonald/Shirodkar), purpose of CC, mid-pregnancy miscarriage/preterm birth, infection history or risk factors, and infection indices on days 1, 3, 5, and 7 after CC. Propensity score matching (PSM) was applied to reduce patient characteristic bias. Statistical analysis of C-reactive protein (CRP), white blood cell (WBC), neutrophil count (NEU), percentage of neutrophil count (NEU_P), interleukin-6 (IL-6), and procalcitonin (PCT) in the infected group compared with the uninfected group was performed using chi-square tests and t-tests. Receiver operating characteristic (ROC) curves were used to further assess the diagnostic value of CRP, PCT, and CRP-PCT in combination.

RESULTS

Among the 619 included patients, 206 patients were matched using PSM and subsequently assessed. PCT values on day 1 and day 3 after CC exhibited significant differences between the two groups in two statistical ways (P < 0.01, P < 0.05). The CRP levels on day 1 were significantly higher in the infected group compared to the uninfected group in two statistical ways (P < 0.05). On day 3, the mean CRP value was significantly elevated in the infected group compared to the uninfected group (P < 0.05). Analyses of IL-6, WBC, NEU, and NEU_P did not yield clinically significant results. The area under the ROC curves for CRP, PCT, and CRP-PCT on day 1 and day 3 were all below 0.7. In the preventive CC group, the AUC values of CRP and CRP-PCT obtained on d1 were found to be higher than 0.7, indicating moderate diagnostic accuracy.

CONCLUSION

For women after CC surgery, especially of preventive aim, increased serum CRP and PCT levels from post-CC day 1 to day 3 may signal a potential postoperative infection, warranting close monitoring.

Prophylactic Cervical Cerclage in Cases Following Cervical Conization at a Japanese Perinatal Center

The objective of this study was to re-examine the effect of cerclage on the possible factors associated with preterm delivery in women who had cervical conization. This was a retrospective cohort study comparing the obstetric outcomes of women with or without prophylactic cervical cerclage in pregnancy following a prior conization and managed at our institute between 2004 and 2023. In this study, there were 75% of pregnant women with a history of cervical conization. In 13 women of these (17%), prophylactic cervical cerclage was performed at 12-17 weeks' gestation. The incidence of preterm delivery was 15 (9/62) and 31% (4/13, p = 0.38) in cases with and without cervical cerclage, respectively. The prevalence of histological chorioamnionitis (CAM) in cases of preterm delivery following cervical cerclage was 100%. Prophylactic cervical cerclage in the cases following conization did not contribute to the prevention of preterm delivery associated with the development of CAM.

Changes in preterm and extremely preterm birth rates in Japan after the introduction of obstetrical practice guidelines in 2008

AIM

Obstetrical guidelines were established in Japan in 2008, and obstetrical diagnoses and treatments were subsequently standardized nationally. We examined changes in the preterm birth rate (PTBR) and extremely preterm birth rate (EPTBR) following the introduction of such guidelines.

METHODS

Information on 50 706 432 live births in Japan between 1979 and 2021, including Japanese reproductive medicine, the childbearing age of pregnant women, and the employment status of reproductive-age women between 2007 and 2020, were obtained from the Japanese government and academic societies. Regression analysis was used to compare chronological changes nationally and those of eight Japanese regions. Regional and national average PTBRs and EPTBRs from 2007 to 2020 were compared by using a repeated measures analysis of variance.

RESULTS

From 1979 to 2007, PTBRs and EPTBRs in Japan increased significantly. However, from 2008, the national PTBR and EPTBR decreased until 2020 (p < 0.001) and 2019 (p = 0.02), respectively. From 2007 to 2020, overall PTBR and EPTBR were 5.68% and 0.255%, respectively. A significant difference in the PTBR and EPTBR existed between the eight Japanese regions. During this period, the number of pregnancies using assisted reproductive technology increased from 19 595 to 60 381, pregnant women became older, the employment rate of those of reproductive age increased, and nonregular employment was 54%, which was 2.5 times higher than for men.

CONCLUSIONS

In Japan, after obstetrical guidelines were enacted in 2008, PTRBs decreased significantly even under the pressure of increasing preterm births. Countermeasures may be necessary for regions showing high PTBRs.

Pre-Cerclage cervical length predicts long-term pregnancy sustenance: A case-control study

Background

This study aimed to assess a predictor of long-term pregnancy sustenance post cervical cerclage in women with or without a medical history of cervical insufficiency.

Materials and methods

We included pregnant women who underwent cerclage at 12–25 weeks gestation in four perinatal medical centers between January 2009 and December 2010. We classified the cerclage modality as ultrasound-indicated cervical cerclage if the pre-cerclage CL was <25 mm because the prophylactic and therapeutic cerclage definitions varied among institutions. The procedure was deemed successful if the pregnancy continued for more than 13 weeks post cerclage. We compared the outcomes of women who underwent successful and unsuccessful cerclage and investigated whether the pre-cerclage CL could predict pregnancy outcomes in women who underwent successful cerclage using receiver-operating characteristic curves.

Results

We screened 114 pregnant women; 91 met the inclusion criteria. Pre-cerclage CL was a moderately accurate predictor of long-term pregnancy sustenance in the successful group (optimal cut-off value: 17 mm; area under the curve: 0.76; P = 0.0016). Approximately 87% of patients with a pre-cerclage CL ≥ 17 mm sustained their pregnancies for more than 13 weeks post cerclage; however, 64% of patients with a pre-cerclage CL < 17 mm did not.

Conclusion

We speculate that the use of other treatment options in addition to cerclage in women with a pre-cerclage CL < 17 mm may result in a successful pregnancy.

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Cervical cerclage encompasses many indications and specific techniques.

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Pre-cerclage cervical length (CL) predicts long-term pregnancy sustenance.

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87% women (pre-cerclage, CL ≥ 17 mm) sustained their pregnancy for >13 weeks.

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64% women (pre-cerclage, CL < 17 mm) did not sustain their pregnancy for >13 weeks.

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Cerclage can be considered in women with a pre-cerclage CL < 17 mm.

Elevated midtrimester maternal plasma cytokines and preterm birth in patients with cerclage

BACKGROUND

Cerclage is used for the prevention of spontaneous preterm birth; however, many patients at high risk of spontaneous preterm birth who have a cerclage in place eventually deliver before term. Although inflammation, measured by biomarkers (eg, cytokines), is a known risk factor for preterm delivery, evaluation of inflammation to determine pregnancy outcomes among patients with cerclage is poorly understood.

OBJECTIVE

We sought to examine levels of maternal plasma inflammatory cytokines in the midtrimester among asymptomatic patients with a cervical cerclage (placed for any indication, including history, ultrasound, and examination indications) to evaluate the association between cytokine levels and preterm birth.

STUDY DESIGN

This was a prospective cohort study of singleton, nonanomalous pregnancies who had a cerclage placed at <24 weeks of gestation from 2015 to 2018 at a single tertiary institution. Maternal plasma was collected perioperatively whenever possible. A custom magnetic bead Luminex cytokine assay was used to measure plasma inflammatory cytokine levels from these stored samples. The primary outcome was preterm birth at <37 weeks of gestation. A statistical cut point was calculated for each cytokine level to assess its optimal sensitivity and specificity for spontaneous preterm birth prediction. Patients were classified as having a "high" or "low" result for each cytokine based on this cut point. Receiver operating characteristic curve analysis was performed to estimate sensitivity, specificity, and positive and negative predictive values for spontaneous preterm birth prediction. Cox proportional-hazards regression modeled the association between the number of "high" inflammatory cytokines and gestational age at delivery, adjusting for confounders. Additional analyses were performed on the subgroup of patients with history-indicated cerclage and those with an ultrasound- or examination-indicated cerclage.

RESULTS

A total of 43 patients participated in this study: 20 (46.5%) had spontaneous preterm birth (median, 30.9 weeks of gestation; interquartile range, 28.4-35.0). Plasma samples were collected at a median of 0 (interquartile range, -2 to 17) days concerning cerclage placement and a median of 18 (interquartile range, 13-21) weeks of gestation. Based on the statistical cut point for each cytokine level, 7% of patients had zero, 20.9% had 1, 18.6% had 2, 20.9% had 3, and 32.6% had ≥4 "high" cytokine results. Each additional "high" cytokine level was associated with earlier delivery (hazard ratio, 1.51; 95% confidence interval, 1.25-1.81) even after controlling for ultrasound- or examination-indication for cerclage (hazard ratio, 1.73; 95% confidence interval, 0.95-3.15). The presence of ≥4 "high" cytokine levels was 70% sensitive and 74% specific for predicting spontaneous preterm birth (area under the curve, 0.846; 95% confidence interval, 0.728-0.964; positive predictive value, 70%; negative predictive value, 73.9%).

CONCLUSION

Among patients with a cervical cerclage, elevated midtrimester maternal plasma cytokine profiles were associated with subsequent preterm birth and can estimate the probability of preterm birth. Confirmation and refinement of this noninvasive panel may provide insight into improved selection of individuals who may benefit from cerclage placement and investigation of therapeutic strategies to mitigate midpregnancy inflammation.

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.

Effects of vaginal microecology and immunity on the pregnancy outcome of cervical cerclage

Objective

To investigate the effects of vaginal microecology and immune status on the pregnancy outcome of cervical cerclage.

Methods

The clinical data of 125 patients with cervical incompetence who underwent transvaginal cervical cerclage in our hospital from January 2018 to January 2021 were collected, based on which the associations of vaginal microecology and related immune cytokines (IL-1β, IL-6, IL-8 and TNF-α) with the cervical cerclage outcome were explored.

Results

All of the 125 patients had singleton pregnancies, who were aged 20–43 years, with a mean of (32.34 ± 5.17) years. The surgery was successful in 104 patients (full-term delivery or survival of premature infants), while unsuccessful in 21 patients (late miscarriage or death of premature infants), revealing a success rate of 83.20%. There were 70 full-term deliveries, 34 premature deliveries (28 survived while 6 died), and 15 late miscarriages. Univariate analysis revealed statistically significant differences in the timing of surgery, gestational age of cerclage, preoperative cervical canal length, genital tract infections and preoperative invasive procedures between the successful and unsuccessful groups (P < 0.05). Insignificant differences were found in the pre-pregnancy body mass index (BMI) (P > 0.05). According to the multivariate analysis results, cerclage timing and genital tract infections were independent risk factors for postoperative pregnancy failure (P < 0.05). The pathogen detection rates in the two groups of pregnant women were analyzed, finding significantly higher incidence of bacterial vaginosis (BV) in the unsuccessful group than in the successful group (P < 0.05). Inter-group comparison revealed that the positive rates for vaginal microenvironmental factors (LE, NAG, SNA, H₂O₂ and pH) were all significantly higher in the unsuccessful group than in the successful group (P < 0.05). Besides, the immune cytokine levels in the cervicovaginal secretions were also all significantly higher in the unsuccessful group than in the successful group (P < 0.05).

Conclusion

The pregnancy outcome of patients undergoing cervical cerclage is associated with the imbalance of vaginal microecology and the levels of IL-1β, IL-6, IL-8 and TNF-α in cervicovaginal secretions.

Growth-profile configuration for specific deformations of tubular organs: A study of growth-induced thinning and dilation of the human cervix

Growth is a significant factor that results in deformations of tubular organs, and particular deformations associated with growth enable tubular organs to perform certain physiological functions. Configuring growth profiles that achieve particular deformation patterns is critical for analyzing potential pathological conditions and for developing corresponding clinical treatments for tubular organ dysfunctions. However, deformation-targeted growth is rarely studied. In this article, the human cervix during pregnancy is studied as an example to show how cervical thinning and dilation are generated by growth. An advanced hyperelasticity theory called morphoelasticity is employed to model the deformations, and a growth tensor is used to represent growth in three principle directions. The computational results demonstrate that both negative radial growth and positive circumferential growth facilitate thinning and dilation. Modeling such mixed growth represents an advancement beyond commonly used uniform growth inside tissues to study tubular deformations. The results reveal that complex growth may occur inside tissues to achieve certain tubular deformations. Integration of further biochemical and cellular activities that initiate and mediate such complex growth remains to be explored.

A new rapid bedside test to diagnose and monitor intraamniotic inflammation in preterm PROM using transcervically collected fluid

BACKGROUND

Microbial invasion of the amniotic cavity, a clinical condition present in approximately 50% of patients with preterm prelabor rupture of membranes, is often associated with intraamniotic inflammation, a risk factor for a short admission-to-delivery interval, early preterm delivery, and neonatal complications. We previously developed a transcervical amniotic fluid collector, the device that allows the collection of fluid noninvasively from the cervical canal when membrane rupture occurs.

OBJECTIVE

This study was designed to determine whether rapid analysis of an interleukin-8 concentration in fluid obtained noninvasively by the transcervical amniotic fluid collector can be used to assess the risk of intraamniotic inflammation. We also compared the diagnostic performance of this point-of-care test for interleukin-8 in transcervically obtained fluid to that of a white blood cell count determined in amniotic fluid retrieved by transabdominal amniocentesis.

STUDY DESIGN

This prospective cohort study was conducted between October 2011 and April 2017. Fluid was retrieved through both transabdominal amniocentesis and the use of a transcervical amniotic fluid collector within 24 hours of amniocentesis in patients with a singleton pregnancy and preterm prelabor rupture of the membranes (16-35 weeks of gestation). Amniotic fluid obtained via amniocentesis was cultured for aerobic and anaerobic bacteria and genital mycoplasmas; a white blood cell count was also measured in amniotic fluid. Intraamniotic infection was diagnosed when microorganisms were identified by the cultivation of amniotic fluid. Intraamniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL) assayed by enzyme-linked immunosorbent assay. Interleukin-8 in cervical fluid obtained by the collector was measured by the point-of-care test that used a test strip and scanner based on the fluorescence immunochromatographic analysis in 2019. The diagnostic indices, predictive values, and likelihood ratios of the 2 different tests were calculated.

RESULTS

First, interleukin-8 concentration ≥9.5 ng/mL in cervical fluid, determined by the point-of-care test, was at the knee of the receiver operating characteristic curve analysis and had a sensitivity of 98% (56/57; 95% confidence interval, 91-99.96%), specificity of 74% (40/54; 95% confidence interval, 60-85%), positive predictive value of 80% (56/70; 95% confidence interval, 72-86%), negative predictive value of 98% (40/41; 95% confidence interval, 85-99.6%), positive likelihood ratio of 3.79 (95% confidence interval, 2.41-5.96), and negative likelihood ratio of 0.02 (95% confidence interval, 0.003-0.17) in the identification of intraamniotic inflammation; a concentration of matrix metalloproteinase-8 >23 ng/mL by enzyme-linked immunosorbent assay had a prevalence of 51% (57/111). Second, a cervical fluid interleukin-8 concentration ≥9.5 ng/mL had significantly higher sensitivity than a transabdominally obtained amniotic fluid white blood cell count (≥19 cells/mm³) in the identification of intraamniotic inflammation (sensitivity: 98% [95% confidence interval, 91-99.96%] vs 84% [95% confidence interval, 72-93%]; P<.05; specificity: 74% [95% confidence interval, 60-85%] vs 76% [95% confidence interval, 62-87%); positive and negative predictive values: 80% [95% confidence interval, 72-86%] and 98% [95% confidence interval, 85-99.6%] vs 79% [95% confidence interval, 69-86%] and 82% [95% confidence interval, 71-89%]) and in the identification of intraamniotic inflammation/infection (gold standard: positive culture for bacteria or a matrix metalloproteinase-8 >23 ng/mL; sensitivity: 91% [95% confidence interval, 82-97%] vs 75% [95% confidence interval, 63-85%]; P<.05).

CONCLUSION

The point-of-care test was predictive of intraamniotic inflammation, based on the determination of interleukin-8 in fluid retrieved by a transcervical amniotic fluid collector. Therefore, the analysis of cervically obtained fluid by such point-of-care test may be used to noninvasively monitor intraamniotic inflammation in patients with preterm prelabor rupture of membranes.

Factors associated with preterm birth in women undergoing cervical cerclage

OBJECTIVES

Cervical cerclage is used to manage women at high risk of late miscarriage (LM) and spontaneous preterm birth (PTB) due to factors such as history of cervical insufficiency (CI), uterine anomaly, cervical surgery and ultrasound (US) diagnosed cervical shortening. Urinary tract infection (UTI) and subsequent pyelonephritis, and bacterial infection are associated with PTB, but their role in PTB after cervical cerclage is unknown. We examined the relationship between UTI and bacterial vaginosis (BV), fetal fibronectin (fFN) test and PTB in women undergoing elective- or US-indicated cervical cerclage. We also investigated whether fetal fibronectin (fFN) test were useful to predict PTB.

STUDY DESIGN

This is a single center, retrospective study of singleton pregnant women at PTB clinic, University College London Hospital (UCLH, 2005-2015) who underwent elective or US-indicated cervical cerclage. Women were tested for UTI and BV before cerclage placement and received mid-gestation fFN testing. Patient data were extracted from the PTB clinic database and electronic records. Statistical analyses used Pearson's chi-square and Mann-Whitney U tests. P values were corrected by Bonferroni method as required.

RESULTS

267 singleton pregnant women attended our clinic with completed birth outcome. Of those, 32.2% (86/267) delivered prematurely. All women with UTI or BV received antibiotic treatment. Women with a UTI before cerclage placement were more likely to deliver preterm when compared to those with negative MSU culture (OR 3.39, 95%CI 1.24-9.27, p = 0.04). Their gestational age at delivery were also lower than those with negative MSU result (36⁺⁶, IQR 31⁺⁴-38⁺²week vs 38⁺¹, IQR 36⁺¹-39⁺⁵-week, p = 0.05). However, UTI after cerclage placement or BV either before or after cerclage placement were not associated with PTB. Women who had a positive fFN result were more likely to deliver preterm (OR 3.85, 95% CI 1.81-8.41, p = 0.0007).

CONCLUSIONS

The presence of a UTI before cervical cerclage is associated with a higher rate of PTB in women who receive a cervical cerclage, even when treated. We did not find an association between pre or post-cerclage BV or post-cerclage UTI and PTB. Further research is needed to elucidate the link between UTI and PTB in women undergoing cervical cerclage.

Predictive value of cervical cytokine, antimicrobial and microflora levels for pre-term birth in high-risk women

Spontaneous preterm birth (sPTB, delivery <37 weeks gestation), accounts for approximately 10% of births worldwide; the aetiology is multifactorial with intra-amniotic infection being one contributing factor. This study aimed to determine whether asymptomatic women with a history of sPTB or cervical surgery have altered levels of inflammatory/antimicrobial mediators and/or microflora within cervical fluid at 22-24 weeks gestation. External cervical fluid was collected from women with history of previous sPTB and/or cervical surgery at 22-24 weeks gestation (n = 135). Cytokine and antimicrobial peptides were measured on a multiplex platform or by ELISA. qPCR was performed for detection of 7 potentially pathogenic bacterial species. IL-8 and IL-1β levels were lower in women who delivered preterm compared to those who delivered at term (IL-8 P = 0.02; IL-1β P = 0.04). There were no differences in elafin or human beta defensin-1 protein levels between the two groups. Multiple bacterial species were detected in a higher proportion of women who delivered preterm than in those who delivered at term (P = 0.005). Cervical fluid IL-8 and IL-1β and microflora have the potential to be used as biomarkers to predict sPTB in high risk women.

Neutrophil elastase in cervical fluid in women with short cervical length

OBJECTIVE

The aim of the study was to determine the relationships between short cervical length (CL) and levels of cervical fluid neutrophil elastase (NE), secretory leukocyte protease inhibitor (SLPI), and interleukin 8 (IL-8) in the second trimester of pregnancy of women who underwent ultrasound-indicated cervical cerclage.

MATERIALS AND METHODS

CL of <25 mm or cervical funneling were included in the short CL group (n = 26) and the normal CL group (n = 22) included women who had CL of ≥25 mm and had no cervical funneling in women between 17 + 0 and 24 + 6 weeks of gestation. Levels of NE, SLPI, and IL-8 were measured by using enzyme-linked immunosorbent assay kits. Mann-Whitney U tests and Spearman's correlation analysis were used for statistical analyses.

RESULTS

Compared with the normal CL group, the short CL group had significantly higher median NE levels (P < 0.001) and higher, though not significant, median IL-8 levels by approximately three times (2107.0 vs. 798.3 pg/mL, P = 0.132). The median SLPI levels in cervical fluid was similar between the two groups (107.6 vs. 103.2 ng/mL, P = 0.499). Short CL had a significant correlations with cervical fluid NE levels (r = -0.475, P = 0.001).

CONCLUSION

Increased cervical fluid NE associated with cervical shortening in second trimester of pregnancy, whereas cervical fluid SLPI had constant levels.

Randomized trial of the efficacy of intravaginal ulinastatin administration for the prevention of preterm birth in women with a singleton pregnancy and both cervical shortening and inflammation of lower genital tract

AIM

To assess the preventive effect on preterm birth of intravaginal ulinastatin (urinary trypsin inhibitor; UTI) administration during the mid-trimester in women with singleton pregnancy and both cervical shortening and lower genital infections.

METHODS

Pregnant women with a short cervical length < 25 mm between 16 and 26 weeks of gestation and who had been diagnosed with a lower genital infection were randomly assigned for intravaginal UTI administration or placebo. All of the women were screened for infection or inflammation of the lower genital tract, and women with negative results were excluded.

RESULTS

Of the 92 patients with a short cervical length who were assessed for eligibility for this study, 86 singleton patients were enrolled. All patients were randomized to one of two treatment groups: patients administered UTI (n = 35) and placebo (n = 35). There were no differences between the two groups in the incidence of preterm delivery before 28, 30, 32, 34 and 37 weeks of gestation and in perinatal outcomes.

CONCLUSION

For women diagnosed with a short cervical length < 25 mm) between 16 and 26 weeks of gestation and lower genital infection, who were at risk of preterm birth, administration of transvaginal UTI with vaginal irrigation showed no apparent benefit. Future research on the efficacy of UTI should evaluate modified modes of UTI application.

Cerclage is associated with the increased risk of preterm birth in women who had cervical conization

Background

The aim of this study was to determine the effect of cerclage in women who underwent cervical conization.

Methods

Study data were collected from the Korea National Health Insurance Claims Database of the Health Insurance Review and Assessment Service for 2009–2013. Women who had a conization in 2009 and a subsequent first delivery between 2009 and 2013 in Korea were enrolled.

Results

Among the women who had conization in 2009, 1075 women had their first delivery between 2009 and 2013. A cerclage was placed in 161 of the women who were treated by conization. The rate of preterm birth was higher in the women who were treated with cerclage following a conization compared with those without cerclage (10.56 vs 4.27, p < 0.01, respectively). The multivariate regression analysis revealed that the women who were treated cerclage following a conization had an increased risk of preterm delivery compared with women without cerclage (odds ratio (OR), 2.6, 95% confidence interval (CI), 1.4–4.9).

Conclusion

Our study showed that cerclage associated with an increased risk of preterm birth and preterm premature rupture of membranes in women who underwent conization. Further studies are required to clarify the mechanism by which cerclage affects the risk of preterm birth.

Cervical cerclage placement decreases local levels of proinflammatory cytokines in patients with cervical insufficiency

BACKGROUND

Cervical insufficiency is characterized by premature, progressive dilation and shortening of the cervix during pregnancy. If left unattended, this can lead to the prolapse and rupture of the amniotic membrane, which usually results in midtrimester pregnancy loss or preterm birth. Previous studies have shown that proinflammatory cytokines such as interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor alpha are up-regulated in normal parturition but are also associated with preterm birth. Studies evaluating such markers in patients with cervical insufficiency have evaluated only their diagnostic potential. Even fewer studies have studied them within the context of cerclage surgery.

OBJECTIVES(S)

The objective of the study was to evaluate the impact of local and systemic inflammatory markers on the pathogenesis of cervical insufficiency and the effect of cerclage surgery on the local immune microenvironment of women with cervical insufficiency.

STUDY DESIGN

We recruited 28 pregnant women (12-20 weeks' gestation) diagnosed with insufficiency and referred for cerclage surgery and 19 gestational age-matched normal pregnant women as controls. Serum and cervicovaginal fluid samples were collected before and after cerclage surgery and during a routine checkup for normal women and analyzed using a targeted 13-plex proinflammatory cytokine assay.

RESULTS

Before surgery, patients with cervical insufficiency had higher levels of interleukin-1β, interleukin-6, interleukin-12, monocyte chemoattractant protein-1 and tumor necrosis factor alpha in cervicovaginal fluid compared to controls, but after surgery, these differences disappeared. No differences were found in serum of insufficiency versus control women. In patients with insufficiency, the levels of interleukin-1β, interleukin-6, interleukin-8, monocyte chemoattractant protein-1, and interferon gamma in cervicovaginal fluid declined significantly after cerclage compared with before intervention, but these changes were not detected in serum.

CONCLUSION

Compared with normal women, patients with cervical insufficiency have elevated levels of proinflammatory cytokines in cervicovaginal fluid but not in serum, suggesting a dysregulation of the local immune environment. Cerclage intervention led to a significant decline in these proinflammatory cytokines, suggesting that cerclage may help reduce local inflammation in cervical insufficiency.

The role of predictive vaginal biomarkers in women with cervical cerclage

Cervical cerclage is currently one of the primary methods of treatment for cervical insufficiency (CI). Identifying methods in order to selectively apply cerclage may allow us to further limit unnecessary procedures. In this regard, a limited number of inflammatory and extracellular matrix biomarkers measurable non-invasively at the level of the cervix have been examined. In this review we summarize the current research on the use of cervical biomarkers in predicting cerclage failure and propose potential objectives for future research.

Maternal Characteristics, Short Mid-Trimester Cervical Length, and Preterm Delivery

We aimed to determine the maternal characteristics (demographics, an obstetric history, and prior cervical excisional procedure) associated with a short mid-trimester cervical length (CL, defined as a CL of ≤ 25 mm) and whether having a short cervix explains the association between these maternal characteristics and spontaneous preterm delivery (SPTD, defined as a delivery before 34 weeks). This is a single-center retrospective cohort study of 3,296 consecutive women with a singleton pregnancy who underwent routine CL measurement between 20 and 24 weeks. Data were collected on maternal age, weight, height, parity, obstetric history (nulliparity; a history of at least 1 SPTD; and at least 1 term birth and no preterm birth [low-risk history group]), and prior cervical excisional procedure. In the multivariate regression analysis, an obstetric history, prior cervical excisional procedure, and gestational age at measurement were the variables significantly associated with short CL. In contrast, maternal weight, height, age, and parity were not significantly associated with short CL. By using the likelihood of SPTD as an outcome variable, logistic regression indicated that short CL and obstetric history, but not prior cervical excisional procedure, were significantly associated with SPTD after adjustment for potential confounders. A history of SPTD and prior cervical excisional procedure were associated with an increased risk of a short mid-trimester CL. A history of SPTD, but not prior cervical excisional procedure, is associated with an increased risk of SPTD, independent of a short CL.

Can the optimal cervical length for placing ultrasound-indicated cerclage be identified?

OBJECTIVE

To assess a continuum of cervical length (CL) cut-offs for the efficacy of ultrasound-indicated cerclage in women with previous spontaneous preterm birth (PTB).

METHODS

This was a planned secondary analysis of a multicenter randomized clinical trial of ultrasound-indicated cerclage for the prevention of PTB in high-risk women. The efficacy of cerclage for preventing recurrent PTB < 35, < 32 and < 24 weeks' gestation was assessed using multivariable logistic regression analysis. Odds ratios (ORs) and CIs were estimated for a range of CL cut-offs using bootstrap regression. The 2.5(th) and 97.5(th) percentiles of bootstrapped ORs determined the CIs. Results were illustrated using smoothed curves superimposed on estimated ORs by CL cut-off.

RESULTS

Of 301 women with a CL < 25 mm, 142 underwent ultrasound-indicated cerclage and 159 did not have cerclage placement. The few cases with CL < 10 mm limited the evaluation to CL cut-offs between < 10 mm and < 25 mm. For PTB < 35 weeks, ORs in women with a cerclage and CL < 25 mm were statistically significantly lower than in those without cerclage, and efficacy was maintained at smaller CL cut-offs. Results were similar for PTB < 32 weeks. For PTB < 24 weeks, results differed, with ORs increasing toward unity (no benefit), with wide CIs, for CL cut-offs between < 10 mm and < 15 mm, attributed to the small number of births < 24 weeks.

CONCLUSIONS

The efficacy of ultrasound-indicated cerclage in women with previous spontaneous PTB varies by action point CL cut-off and by PTB gestational age of interest. Cerclage significantly reduces the risk of PTB < 35 and < 32 weeks, at CL cut-offs between < 10 mm and < 25 mm, with the greatest reduction at shorter CL, affirming that women with prior spontaneous PTB and a short CL are appropriate candidates for ultrasound-indicated cerclage. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Biophysical and Biochemical Screening for the Risk of Preterm Labor: An Update

The heterogeneous causes of spontaneous preterm birth make prediction and prevention difficult. Recently developed biochemical and biophysical tests add significantly to clinicians' ability to evaluate and treat women at risk for spontaneous preterm birth. The primary importance of transvaginal cervical sonography and cervicovaginal fetal fibronectin lies in the high negative predictive values of the tests for preterm delivery risk. Cervical length may be useful in identifying women who are candidates for cervical cerclage or progesterone therapy for preterm birth prevention. Together, cervical length and fibronectin can be used in the triaging of women symptomatic for preterm labor.

Preoperative and postoperative serum C-reactive protein levels to predict the outcome of ultrasound-indicated cerclage

Objective

To assess the role of preoperative and postoperative serum C-reactive protein (CRP) level on the prediction of pregnancy outcomes following ultrasound-indicated cerclage (UIC).

Methods

We retrospectively reviewed the medical records 44 women who underwent UIC between January 2011 and December 2011. UIC was performed between 14 and 24 weeks of gestation in women with short cervix. We divided UIC patients into two groups according to the gestational age at delivery (34 weeks) and compared the two groups. Group A was defined as patients who delivered ≥34 weeks of gestation, and group B as patients delivered <34 weeks. Correlation and receiver-operating characteristic curves were also analyzed for the prediction of preterm birth after UIC.

Results

Thirty women delivered ≥34 weeks (group A) and 14 women delivered <34 weeks (group B). Pre- and post-cerclage CRP were significantly lower in group A (pre-cerclage CRP, 1.1±1.0 vs. 11.4±6.2 mg/dL, P<0.001; post-cerclage CRP, 0.6±0.5 vs. 7.4±7.2 mg/dL, P<0.001). The mean gestational age at delivery in group A was 37.7±1.8 weeks and that in group B was 26.9±4.3 weeks (P<0.001). There were significant negative correlations between pre- and post-cerclage CRP and latency from UIC to delivery (r=-0.82, P<0.001; r=-0.70, P<0.001, respectively).

Conclusion

Both pre- and post-cerclage CRP were useful in predicting the preterm birth following UIC.

Prediction of spontaneous preterm birth in women with cervical insufficiency: Comprehensive analysis of multiple proteins in amniotic fluid

AIM

The purpose of this study is to determine whether proinflammatory cytokines and matrix metalloproteinases (MMPs) in amniotic fluid (AF), alone or in combination with clinical risk factors, can predict spontaneous preterm delivery (SPTD) at < 34 weeks in women with cervical insufficiency.

METHODS

This retrospective cohort study included 57 consecutive singleton pregnant women (17-28 gestational weeks) with cervical insufficiency who underwent amniocentesis. AF was assayed for five cytokines (interleukin [IL]-6, IL-8, monocyte chemotactic protein-1, macrophage inflammatory protein [MIP]-1α, and MIP-1β) and five MMPs (MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9) using multiplex immunoassay kits. The primary outcome measure was SPTD at < 34 weeks.

RESULTS

The AF concentrations of MMP-1, MMP-3, MMP-8, MMP-9, IL-6, IL-8, MIP-1α and MIP-1β were significantly higher in women with SPTD at < 34 weeks. Women who had SPTD at < 34 weeks were younger, had significantly more advanced cervical dilatation at presentation and a higher rate of positive AF cultures. Using stepwise regression analysis, a combined prediction model was developed that included maternal age, cervical dilatation at presentation, AF MMP-1 and AF MMP-8 (area under the curve [AUC] 0.951). The AUC for this model was significantly greater than for any single protein alone in AF or for each of the clinical risk factors alone.

CONCLUSION

A model combining proteins in AF and clinical factors can improve the accuracy of risk prediction for preterm birth and this combination is more accurate than each of the biomarkers alone in women with cervical insufficiency.

Comparative Analysis of Midtrimester Amniotic Fluid Cytokine Levels to Predict Spontaneous Very Pre-term Birth in Patients with Cervical Insufficiency

PROBLEM

Few studies have investigated the roles of cytokines and chemokines in women with cervical insufficiency, and those that have done so evaluated only a limited number of cytokines in amniotic fluid.

METHOD OF STUDY

A retrospective cohort study enrolled 71 patients undergoing physical examination-indicated cerclage to determine whether expanded amniotic fluid cytokine levels predict spontaneous very pre-term birth (≤32 weeks of gestation) in patients with cervical insufficiency. Analysis of multiple cytokines and chemokines was performed with the multiplex immunoassay.

RESULTS

Sixty-seven amniotic fluid samples were available for analysis and assayed for 15 cytokines. Thirty-eight (56.7%) patients delivered pre-term. Of these, 26 (38.8%) were spontaneous very pre-term births. Most cytokine levels were significantly increased in the amniotic fluid from the study group when compared with those from controls. The levels of interleukin-1β (IL-1β), IL- 6, IL- 7, IL-15, IL-17α, tumour necrosis factor-α (TNF-α), MIP-1α, and MIP-1β were higher in patients with a very pre-term delivery than in those with a late pre-term delivery. IL-1β, IL-6, IL-7, IL-17α, TNF-α, and cervical dilation were independently associated with a very pre-term birth.

CONCLUSION

Intra-amniotic inflammation may contribute to cervical insufficiency, and the severity of inflammation is associated with a very pre-term birth in women with cervical insufficiency.

Do the levels of tumor makers or proinflammatory cytokines in mid-trimester cervical fluid predict early-stage cervical shortening?

AIM

In the present study, we aimed to assess the biomarkers in mid-trimester cervical fluid that can predict early stage cervical shortening.

MATERIAL AND METHODS

We obtained cervical swab specimens from 96 gravidas, after which the cervical length was measured, at approximately 20 weeks of gestation. Cervical length was measured again at 4 weeks after the initial examination. Cervical shortening was noted in 20 women between 20 and 24 weeks of gestation (group A), whereas no cervical shortening was noted in 76 women (group B). We evaluated the use of the levels of tumor markers, proinflammatory cytokines, and matrix metalloproteinase-8 (MMP-8) as candidate biomarkers. CA-125 and carcinoembryonic antigen levels were determined by using an automatic immunoassay system in both groups. Furthermore, IL-1β, IL-8, tumor necrosis factor-α, and MMP-8 levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

The levels of inflammatory cytokines and MMP-8 did not differ between the two groups, and were not correlated with cervical length or the change in cervical length. Although CA-125 and carcinoembryonic antigen levels were higher in group A, they were not statistically significant (P = 0.304 and 0.092, respectively).

CONCLUSION

Early stage cervical shortening in mid-trimester was not associated with an increase in the levels of tumor markers or proinflammatory cytokines in cervical fluid.

[Cervical cerclage]

Cervical cerclage aims to strengthen not only the mechanical properties of the cervix, but also its immunological and anti-infectious functions. The demonstration of a strong interrelation between cervical insufficiency as well as decreased cervical length at endo-vaginal ultrasonography and infection has changed the indications cerclage. Actually we can distinguish three indications for cerclage: prophylactic, for obstetrical history; therapeutic, for shortened cervical length at ultrasonography in patients at risk and; emergency cerclage in case of threatening cervix at physical examination. The McDonald's technique is the most recommended. In case of failure, it is proposed to realize cerclage at a higher level on the cervix either by vaginal or abdominal route.

Detection of microbial invasion of the amniotic cavity by analysis of cervicovaginal proteins in women with preterm labor and intact membranes

OBJECTIVE

Microbial invasion of the amniotic cavity (MIAC) is common in early preterm labor and is associated with maternal and neonatal infectious morbidity. MIAC is usually occult and is reliably detected only with amniocentesis. We sought to develop a noninvasive test to predict MIAC based on protein biomarkers in cervicovaginal fluid (CVF) in a cohort of women with preterm labor (phase 1) and to validate the test in an independent cohort (phase 2).

STUDY DESIGN

This was a prospective study of women with preterm labor who had amniocentesis to screen for MIAC. MIAC was defined by positive culture and/or 16S ribosomal DNA results. Nine candidate CVF proteins were analyzed by enzyme-linked immunosorbent assay. Logistic regression was used to identify combinations of up to 3 proteins that could accurately classify the phase 1 cohort (N = 108) into those with or without MIAC. The best models, selected by area under the curve (AUC) of the receiver operating characteristic curve in phase 1, included various combinations of interleukin (IL)-6, chemokine (C-X-C motif) ligand 1 (CXCL1), alpha fetoprotein, and insulin-like growth factor binding protein-1. Model performance was then tested in the phase 2 cohort (N = 306).

RESULTS

MIAC was present in 15% of cases in phase 1 and 9% in phase 2. A 3-marker CVF model using IL-6 plus CXCL1 plus insulin-like growth factor binding protein-1 had AUC 0.87 in phase 1 and 0.78 in phase 2. Two-marker models using IL-6 plus CXCL1 or alpha fetoprotein plus CXCL1 performed similarly in phase 2 (AUC 0.78 and 0.75, respectively), but were not superior to CVF IL-6 alone (AUC 0.80). A cutoff value of CVF IL-6 ≥463 pg/mL (which had 81% sensitivity in phase 1) predicted MIAC in phase 2 with sensitivity 79%, specificity 78%, positive predictive value 38%, and negative predictive value 97%.

CONCLUSION

High levels of IL-6 in CVF are strongly associated with MIAC. If developed into a bedside test or rapid laboratory assay, cervicovaginal IL-6 might be useful in selecting patients in whom the probability of MIAC is high enough to warrant amniocentesis or transfer to a higher level of care. Such a test might also guide selection of potential subjects for treatment trials.

Rapid evaluation of the absence of inflammation after rupture of membranes

OBJECTIVES

The aim of this study was to validate the results of an immunochromatographic bedside test to detect IL6 and IL8 in vaginal secretions after rupture of membranes (ROM) with results obtained by ELISA tests.

METHODS

A prospective cohort of 60 women with ROM or preterm ROM (PROM) was recruited. An immunochromatographic bedside test was performed with vaginal secretions samplings at admission, every 48 hrs until labor and during labor. Remaining samples were frozen for ELISA analysis. The results of bedside tests were compared to those from ELISA analysis for 114 samples.

RESULTS

With all samples combined, the positive predictive values were 50% for IL6 and 86.8% for IL8 and the negative predictive values were 97.4% for IL6 and 53.3% for IL8. Kappa coefficients were 0.54 for IL6 and 0.41 for IL8.

CONCLUSION

Our findings show that a bedside test can detect the absence of IL6 in vaginal secretions. This result suggests that bedside test could be used for expectant management after premature PROM to inform the attending physician of the absence of inflammation in vaginal secretions.

Transvaginal cervical cerclage: evidence for perioperative management strategies

The objective was to review the evidence supporting various perioperative technical and management strategies for transvaginal cervical cerclage. We performed MEDLINE, PubMed, EMBASE, and COCHRANE searches with the terms, cerclage, cervical cerclage, cervical insufficiency, and randomized trials, plus each technical aspect (eg, suture, amniocentesis, etc) considered. The search spanned 1966 through September 2012 and was not restricted by language. Each retrieved manuscript was carefully evaluated, and any pertinent references from the reports were also obtained and reviewed. All randomized trials covering surgical and selected perioperative, nonsurgical aspects of cerclage were included in the review. The evidence was assessed separately for history-, ultrasound-, and physical examination-indicated cerclage. Evidence levels according to the new method outlined by the US Preventive Services Task Force were assigned based on the evidence. There are no grade A high-certainty recommendations regarding technical aspects of transvaginal cervical cerclage. Grade B moderate-certainty recommendations include performing a fetal ultrasound before cerclage to ensure fetal viability, confirm gestational age, and assess fetal anatomy to rule out clinically significant structural abnormalities; administering spinal, and not general, anesthesia; performing a McDonald cerclage, with 1 stitch, placed as high as possible; and outpatient setting. Unfortunately, no other recommendations can be made regarding the other technical aspects of cerclage.

Cervical mucus properties stratify risk for preterm birth

BACKGROUND

Ascending infection from the colonized vagina to the normally sterile intrauterine cavity is a well-documented cause of preterm birth. The primary physical barrier to microbial ascension is the cervical canal, which is filled with a dense and protective mucus plug. Despite its central role in separating the vaginal from the intrauterine tract, the barrier properties of cervical mucus have not been studied in preterm birth.

METHODS AND FINDINGS

To study the protective function of the cervical mucus in preterm birth we performed a pilot case-control study to measure the viscoelasticity and permeability properties of mucus obtained from pregnant women at high-risk and low-risk for preterm birth. Using extensional and shear rheology we found that cervical mucus from women at high-risk for preterm birth was more extensible and forms significantly weaker gels compared to cervical mucus from women at low-risk of preterm birth. Moreover, permeability measurements using fluorescent microbeads show that high-risk mucus was more permeable compared with low-risk mucus.

CONCLUSIONS

Our findings suggest that critical biophysical barrier properties of cervical mucus in women at high-risk for preterm birth are compromised compared to women with healthy pregnancy. We hypothesize that impaired barrier properties of cervical mucus could contribute to increased rates of intrauterine infection seen in women with preterm birth. We furthermore suggest that a robust association of spinnbarkeit and preterm birth could be an effectively exploited biomarker for preterm birth prediction.

[Management of patients with a history of late abortion or very premature delivery]

Patients have a very late abortion or premature delivery in 2-3 % of pregnancies. Management in a subsequent pregnancy should seek an infection, a fetal cause (aneuploidy, malformation syndrome, intrauterine death) or vascular pathology (preeclampsia, IUGR, intrauterine death). In women with a late abortion or very premature childbirth history, several preventive treatments of prematurity are now available. The main cause of prematurity is ascending infection from the vagina. Cerclage or pessary is designed to better isolate the uterine cavity. Their effectiveness has been validated in patients for whom the repeated measurement of cervical length by transvaginal ultrasound shows a cervical length <25mm. Early pregnancy vaginosis and treatment with Dalacin(®) seem to significantly reduce the risk of prematurity. Finally, the routine administration of intramuscular or vaginal progesterone at the beginning of the 2(nd) quarter also proved effective in several randomized studies.

Limited relationship between cervico-vaginal fluid cytokine profiles and cervical shortening in women at high risk of spontaneous preterm birth

Objective

To determine the relationship between high vaginal pro-inflammatory cytokines and cervical shortening in women at high risk of spontaneous preterm labor and to assess the influence of cervical cerclage and vaginal progesterone on this relationship.

Methods

This prospective longitudinal observational study assessed 112 women with at least one previous preterm delivery between 16 and 34 weeks’ gestation. Transvaginal cervical length was measured and cervico-vaginal fluid sampled every two weeks until 28 weeks. If the cervix shortened (<25 mm) before 24 weeks’ gestation, women (cases) were randomly assigned to cerclage or progesterone and sampled weekly. Cytokine concentrations were measured in a subset of cervico-vaginal fluid samples (n = 477 from 78 women) by 11-plex fluid-phase immunoassay.

Results

All 11 inflammatory cytokines investigated were detected in cervico-vaginal fluid from women at high risk of preterm birth, irrespective of later cervical shortening. At less than 24 weeks’ gestation and prior to intervention, women destined to develop a short cervix (n = 36) exhibited higher cervico-vaginal concentrations than controls (n = 42) of granulocyte-macrophage colony-stimulating factor [(GM-CSF) 16.2 fold increase, confidence interval (CI) 1.8–147; p = 0.01] and monocyte chemotactic protein-1 [(MCP-1) 4.8, CI 1.0–23.0; p = 0.05]. Other cytokines were similar between cases and controls. Progesterone treatment did not suppress cytokine concentrations. Interleukin (IL)-6, IL-8, granulocyte colony-stimulating factor (G-CSF), interferon (IFN)-γ and tumour necrosis factor (TNF)-α concentrations were higher following randomization to cerclage versus progesterone (p<0.05). Cerclage, but not progesterone treatment, was followed by a significant increase in cervical length [mean 11.4 mm, CI 5.0–17.7; p<0.001].

Conclusions

Although GM-CSF and MCP-1 cervico-vaginal fluid concentrations were raised, the majority of cervico-vaginal cytokines did not increase in association with cervical shortening. Progesterone treatment showed no significant anti-inflammation action on cytokine concentrations. Cerclage insertion was associated with an increase in the majority of inflammatory markers and cervical length.

Prevention of preterm labour via the modulation of inflammatory pathways

Pregnancy is characterized by a complex interplay of inflammatory events regulated by both the innate and acquired immune systems. Similarly, parturition can be viewed as the activation of "pro-labour" inflammatory pathways, which drive cervical ripening and myometrial activation. Premature activation of these pathways, for example, by infection, can lead to preterm labour and birth. Nuclear factor κβ is a key modulator of these pathways and functions by regulating the expression of prostaglandins, chemokines and pro-inflammatory cytokines involved in both term and preterm labour. Future design of therapeutics that target key mediators of inflammation and immune activation would therefore be a rational approach for preventing preterm labour and immune-mediated neonatal brain damage.

Prevention of preterm birth

Preterm birth (delivery before 37 completed weeks of gestation) is common and rates are increasing. In the past, medical efforts focused on ameliorating the consequences of prematurity rather than preventing its occurrence. This approach resulted in improved neonatal outcomes, but it remains costly in terms of both the suffering of infants and their families and the economic burden on society. Increased understanding of the pathophysiology of preterm labor has altered the approach to this problem, with increased focus on preventive strategies. Primary prevention is a limited strategy which involves public education, smoking cessation, improved nutritional status and avoidance of late preterm births. Secondary prevention focuses on recurrent preterm birth which is the most recognisable risk factor. Widely accepted strategies include cervical cerclage, progesterone and dedicated clinics. However, more research is needed to explore the role of antibiotics and anti-inflammatory treatments in the prevention of this complex problem.

Vaginal progesterone in women with an asymptomatic sonographic short cervix in the midtrimester decreases preterm delivery and neonatal morbidity: a systematic review and metaanalysis of individual patient data

OBJECTIVE

To determine whether the use of vaginal progesterone in asymptomatic women with a sonographic short cervix (≤ 25 mm) in the midtrimester reduces the risk of preterm birth and improves neonatal morbidity and mortality.

STUDY DESIGN

Individual patient data metaanalysis of randomized controlled trials.

RESULTS

Five trials of high quality were included with a total of 775 women and 827 infants. Treatment with vaginal progesterone was associated with a significant reduction in the rate of preterm birth <33 weeks (relative risk [RR], 0.58; 95% confidence interval [CI], 0.42-0.80), <35 weeks (RR, 0.69; 95% CI, 0.55-0.88), and <28 weeks (RR, 0.50; 95% CI, 0.30-0.81); respiratory distress syndrome (RR, 0.48; 95% CI, 0.30-0.76); composite neonatal morbidity and mortality (RR, 0.57; 95% CI, 0.40-0.81); birthweight <1500 g (RR, 0.55; 95% CI, 0.38-0.80); admission to neonatal intensive care unit (RR, 0.75; 95% CI, 0.59-0.94); and requirement for mechanical ventilation (RR, 0.66; 95% CI, 0.44-0.98). There were no significant differences between the vaginal progesterone and placebo groups in the rate of adverse maternal events or congenital anomalies.

CONCLUSION

Vaginal progesterone administration to asymptomatic women with a sonographic short cervix reduces the risk of preterm birth and neonatal morbidity and mortality.

Amniotic fluid inflammatory score is associated with pregnancy outcome in patients with mid trimester short cervix

OBJECTIVE

We propose a novel amniotic fluid inflammatory score from a comprehensive cytokine analysis of patients with mid-trimester short cervix.

STUDY DESIGN

Amniotic fluid from singleton gestations (n = 44) with a cervical length of ≤25 mm between 16-24 weeks was assayed for 25 inflammatory mediators. Patient data were stratified according to gestational age at delivery (<34 vs ≥34 weeks). Mediators that reached statistical significance were included in the amniotic fluid inflammatory score. Patients were assigned 1 point for each significant mediator if their level was in the upper quartile. The amniotic fluid inflammatory score was determined, and its relationship to other clinical characteristics was examined.

RESULTS

Fourteen mediators met the criteria. A score of ≥8 was predictive of delivery at <34 weeks' gestation (sensitivity, 87.0%; specificity, 100%; positive predictive value, 100%; negative predictive value, 87.5%). Twenty patients had a high inflammatory score (≥8); 24 patients had a low score. All patients with a high inflammatory score delivered at <30 weeks' gestation.

CONCLUSION

The amniotic fluid inflammatory score is related to delivery outcome and clinical characteristics.

Upregulated amniotic fluid cytokines and chemokines in emergency cerclage with protruding membranes

PROBLEM  To identify the prognostic factors for pregnancy outcome in women who received emergency cerclage for dilated cervix with protruding membranes. METHOD OF STUDY  A prospective cohort study was performed, and a total of 14 women who received emergency cerclage were included. Clinical features and laboratory findings including amniotic fluid cytokines and chemokines were compared between women who had successful pregnancy (survival group, n = 6) and those who had perinatal death (non-survival group, n = 8). Five healthy pregnant women served for normal controls for amniotic fluid study. RESULTS  The overall neonatal survival was 42.9% in women with emergency cerclage. Serum C-reactive protein levels on postoperative day 3 and 7 were significantly higher in non-survival group when compared with those in survival group (P = 0.002, P = 0.01). Amniotic fluid levels of interleukin (IL)-1α, IL-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α, and monocyte chemoattractant protein-1 levels of the patients were significantly higher than those of normal controls. Amniotic fluid levels of IL-1α, IL-1β, and IL-8 were significantly increased in the non-survival group when compared with those of the survival group. CONCLUSION  Systemic and local inflammatory markers including proinflammatory cytokines and chemokines may predict pregnancy outcome in women with emergency cerclage for dilated cervix with protruding membranes.

C-reactive protein levels at pre-/post-indicated cervical cerclage predict very preterm birth

AIMS

To investigate the relation between serum levels of C-reactive protein (CRP) at pre-/post-cerclage points and preterm birth at <33 weeks of gestation in women with indicated cervical cerclage (CC).

METHODS

Fifty-eight women with CC indicated for a short or soft cervix, but no visible or protruding fetal membranes into the vagina, between 17 and 26 weeks of gestation, were reviewed. Serum CRP levels were examined three times: just before cerclage, and on day 1 and day 2 post-cerclage.

RESULTS

Serum CRP levels on day 1 and day 2, but not just before cerclage, predicted the occurrence of very preterm birth. In women with cervical dilatation of <3.0 cm, serum CRP levels on post-cerclage day 1 were associated with the increase of very preterm birth [CRP ≥1.5 mg/dL vs. <1.5 mg/dL: 4/5 (80%) vs. 8/31 (26%), P=0.033]. In women with cervical dilatation of <3.0 cm, serum CRP ≥3.0 mg/dL on post-cerclage day 2 was also associated with the increase of very preterm birth.

CONCLUSION

In women with indicated CC between 17 and 26 weeks of gestation, increased levels of serum CRP on post-cerclage day 1 or 2 might be ominous signs for very preterm birth.

Management strategies for the prevention of preterm birth: Part II - Update on cervical cerclage

PURPOSE OF REVIEW

Cerclage was devised more than 50 years ago based on the hypothesis that for some women, weakness or malfunction of the cervix has a causative role in the pathway to preterm birth (PTB). There have been many theories around the concept of cervical insufficiency but not much in the way of convincing evidence. The purpose of this review was to follow the recent developments in risk identification and prognostication of PTB in connection with appropriately targeted prophylactic interventions.

RECENT FINDINGS

Sonographic cervical length measurement has emerged as an effective prognosticator for PTB in all populations studied so far, independently of obstetric history, consequently deriving a wider applicability than other predictors of PTB. However, the mechanisms leading to cervical shortening are poorly understood, and it cannot be assumed that all cases with a short cervix would benefit from cerclage. Specific conditions may actually reduce the efficacy and advisability of cerclage. For this reason, attempts have been made recently to further characterize the short cervix, leading to the conclusion that only women with a short cervix in the absence of infection/inflammation may be candidates for cerclage. Furthermore, two recent randomized trials of cerclage in women with short cervix on a second trimester ultrasound suggested a benefit with cerclage in PTB rate reduction only in those cases with a cervical length of less than 15 mm.

SUMMARY

The existent literature has treated PTB prevention focusing exclusively on either progesterone use or cerclage, leaving the practitioners without any guidance on when to proceed with medical or surgical prophylaxis. Understanding that high-risk populations are not homogeneous and no single-approach modality is likely to be generally applicable, we have combined the available evidence on both progesterone and cerclage to provide guidance on how to identify subgroups of women at significantly increased risk for PTB and how to preferentially consider progesterone versus cerclage.

17-alpha-hydroxyprogesterone caproate for the prevention of preterm birth in women with prior preterm birth and a short cervical length

OBJECTIVE

We sought to evaluate 17-alpha-hydroxyprogesterone caproate (17P) for prevention of preterm birth (PTB) in women with prior spontaneous PTB (SPTB) and cervical length (CL) <25 mm.

STUDY DESIGN

We conducted planned secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development-sponsored randomized trial evaluating cerclage for women with singleton gestations, prior SPTB (17-33 6/7 weeks), and CL <25 mm between 16-22 6/7 weeks. Women were stratified at randomization to intent to use or not use 17P. The effect of 17P was analyzed separately for cerclage and no-cerclage groups. Primary outcome was PTB <35 weeks.

RESULTS

In 300 women, 17P had no effect on PTB <35 weeks in either cerclage (P = .64) or no-cerclage (P = .51) groups. Only PTB <24 weeks (odds ratio, 0.08) and perinatal death (odds ratio, 0.14) were significantly lower for those with 17P in the no-cerclage group.

CONCLUSION

17P had no additional benefit for prevention of PTB in women who had prior SPTB and got ultrasound-indicated cerclage for CL <25 mm. In women who did not get cerclage, 17P reduced previable birth and perinatal mortality.

Prematurity prevention: the role of cerclage

PURPOSE OF REVIEW

To summarize the literature on the value of cervical cerclage for the prevention of preterm birth and present the recent advances in its clinical application.

RECENT FINDINGS

The diagnosis of cervical insufficiency is difficult as there are no objective diagnostic criteria. Although widely used, the value of cervical cerclage is still a matter of controversy. The current literature suggests that cerclage placement can prevent preterm delivery in women with a history of at least three second-trimester losses or at least three preterm births and in those with a history of prematurity who have a cervical length of less than 25 mm in the second trimester. It is also possible to improve the perinatal outcome in patients with cervical dilation in the mid-trimester. It is not indicated in multiple pregnancies, however. Further research is needed in methods of excluding inflammation in women with cervical changes on ultrasound prior to cerclage insertion. Transabdominal or laparoscopic cerclage seems to be a promising alternative in women with a history of transvaginal cerclage failure.

SUMMARY

Strict recommendations on the proper use of cerclage cannot be easily made. Data from randomized trials do not support what the current practice in many cases is.