A multi-centre, non-inferiority, randomised controlled trial to compare a cervical pessary with a cervical cerclage in the prevention of preterm delivery in women with short cervical length and a history of preterm birth - PC study

Vaginal microbiota and spontaneous preterm birth in pregnant women at high risk of recurrence

We describe vaginal microbiota, including Gardnerella species and sexually transmitted infections (STIs), during pregnancy and their associations with recurrent spontaneous preterm birth (sPTB). We performed a prospective cohort study in a tertiary referral centre in the Netherlands, among pregnant women with previous sPTB <34 weeks' gestation. Participants collected three vaginal swabs in the first and second trimester. Vaginal microbiota was profiled with 16S rDNA sequencing. Gardnerella species and STI's were tested with qPCR. Standard care was provided according to local protocol, including screening and treatment for bacterial vaginosis (BV), routine progesterone administration and screening for cervical length shortening. Of 154 participants, 26 (16.9 %) experienced recurrent sPTB <37 weeks' gestation. Microbiota composition was not associated with sPTB. During pregnancy, the share of Lactobacillus iners-dominated microbiota increased at the expense of diverse microbiota between the first and second trimester. This change coincided with treatment for BV, demonstrating a similar change in microbiota composition after treatment. In this cohort of high-risk women, we did not find an association between vaginal microbiota composition and recurrent sPTB. This should be interpreted with care, as these women were offered additional preventive therapies to reduce sPTB according to national guidelines including progesterone and BV treatment. The increase observed in L. iners dominated microbiota and the decrease in diverse microbiota mid-gestation was most likely mediated by BV treatment. Our findings suggest that in recurrent sPTB occurring despite several preventive therapies, the microbe-related etiologic contribution might be limited.

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations

BACKGROUND

Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies.

OBJECTIVES

To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeks' gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeks' gestation.

SEARCH METHODS

We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts & Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies.

SELECTION CRITERIA

Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeks' gestation, respectively. The reference standard was detection of anomalies at birth or postmortem.

DATA COLLECTION AND ANALYSIS

Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity.

MAIN RESULTS

Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons.

AUTHORS' CONCLUSIONS

A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeks' gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeks' gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeks' gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.

Cost-effectiveness of pessary therapy versus surgery for symptomatic pelvic organ prolapse: an economic evaluation alongside a randomised non-inferiority controlled trial

OBJECTIVE

To evaluate the cost-effectiveness of pessary therapy as an initial treatment option compared with surgery for moderate to severe pelvic organ prolapse (POP) symptoms in secondary care from a healthcare and a societal perspective.

DESIGN

Economic evaluation alongside a multicentre randomised controlled non-inferiority trial with a 24-month follow-up.

SETTING

21 hospitals in the Netherlands, recruitment conducted between 2015 and 2022.

PARTICIPANTS

1605 women referred to secondary care with symptomatic prolapse stage ≥2 were requested to participate. Of them, 440 women gave informed consent and were randomised to pessary therapy (n=218) or to surgery (n=222) in a 1:1 ratio stratified by hospital.

INTERVENTIONS

Pessary therapy and surgery.

PRIMARY AND SECONDARY OUTCOME MEASURES

The Patient Global Impression of Improvement (PGI-I), a 7-point scale dichotomised into successful versus unsuccessful, with a non-inferiority margin of -10%; quality-adjusted life-years (QALYs) measured by the EQ-5D-3L; healthcare and societal costs were based on medical records and the institute for Medical Technology Assessment questionnaires.

RESULTS

For the PGI-I, the mean difference between pessary therapy and surgery was -0.05 (95% CI -0.14; 0.03) and -0.03 (95% CI -0.07; 0.002) for QALYs. In total, 54.1% women randomised to pessary therapy crossed over to surgery, and 3.6% underwent recurrent surgery. Healthcare and societal costs were significantly lower in the pessary therapy (mean difference=-€1807, 95% CI -€2172; -€1446 and mean difference=-€1850, 95% CI -€2349; -€1341, respectively). The probability that pessary therapy is cost-effective compared with surgery was 1 at willingness-to-pay thresholds between €0 and €20 000/QALY gained from both perspectives.

CONCLUSIONS

Non-inferiority of pessary therapy regarding the PGI-I could not be shown and no statistically significant differences in QALYs between interventions were found. Due to significantly lower costs, pessary therapy is likely to be cost-effective compared with surgery as an initial treatment option for women with symptomatic POP treated in secondary care.

TRIAL REGISTRATION NUMBER

NTR4883.

A Comparison of Vaginal and Intramuscular Progesterone for the Prevention of Recurrent Preterm Birth

OBJECTIVE

This study aimed to examine whether vaginal progesterone is noninferior to 17-α hydroxyprogesterone caproate (17OHP-C) in the prevention of recurrent preterm birth (PTB).

STUDY DESIGN

This retrospective cohort study included singleton pregnancies among women with a history of spontaneous PTB who received prenatal care at a single tertiary center from 2011 to 2016. Pregnancies were excluded if progesterone was not initiated prior to 24 weeks or the fetus had a major congenital anomaly. The primary outcome was PTB <37 weeks. A priori, noninferiority was to be established if the upper bound of the adjusted two-sided 90% confidence interval (CI) for the difference in PTB fell below 9%. Inverse probability of treatment weighting (IPTW) was used to carefully control for confounding associated with choice of treatment and PTB. Adjusted differences in PTB proportions were estimated via IPTW regression, with standard errors adjustment for multiple pregnancies per woman. Secondary outcomes included PTB <34 and <28 weeks, spontaneous PTB, neonatal intensive care unit admission, and gestational age at delivery.

RESULTS

Among 858 pregnancies, 41% (n = 353) received vaginal progesterone and 59% (n = 505) were given 17OHP-C. Vaginal progesterone use was more common later in the study period, and among women who established prenatal care later, had prior PTBs at later gestational ages, and whose race/ethnicity was neither non-Hispanic white nor non-Hispanic Black. Vaginal progesterone did not meet noninferiority criteria compared with 17-OHPC in examining PTB <37 weeks, with an IPTW adjusted difference of 3.4% (90% CI: -3.5, 10.3). For secondary outcomes, IPTW adjusted differences between treatment groups were generally small and CIs were wide.

CONCLUSION

We could not conclude noninferiority of vaginal progesterone to 17OHP-C; however, women and providers may be willing to accept a larger difference (>9%) when considering the cost and availability of vaginal progesterone versus 17OHP-C. A well-designed randomized trial is needed.

KEY POINTS

· Vaginal progesterone is not noninferior to 17OHP-C.. · PTB risk may be 10% higher with vaginal progesterone.. · Associations did not differ based on obesity status..

Decrease in perinatal mortality after closure of obstetric services in a community hospital in Amsterdam, The Netherlands. A retrospective cohort study

OBJECTIVE

To assess differences in adverse maternal and neonatal outcomes before and after closure of a secondary obstetric care unit of a community hospital in an urban district.

STUDY DESIGN

Retrospective cohort study using aggregated data from National Perinatal Registry of the Netherlands (PERINED) in the very urban region of Amsterdam, consisting of data of five secondary and two tertiary hospitals. We assessed maternal and neonatal outcomes in singleton hospital births between 24⁺⁰ weeks of gestational age (GA) up to 42⁺⁶ weeks. Data of 78.613 births were stratified in two groups: before closure (years 2012-2015) and after closure (2016-2019).

RESULTS

Perinatal mortality decreased significantly from 0.84 % to 0.63 % (p = 0.0009). The adjusted odds ratio (aOR) of the closure on perinatal mortality was 0.73 (95 % CI 0.62-0.87). Both antepartum death (0.46 % vs 0.36 %, p = 0.02) and early neonatal death (0.38 % vs 0.28 %, p = 0.015) declined after closure of the hospital. The number of preterm births decreased significantly (8.7 % vs 8.1 %, p=<0.007) as well as number of neonates with congenital abnormalities (3.2 % vs2.2 %, p=<0.0001). APGAR < 7 after 5 min increased (2.3 % vs 2.5 %, p = 0.04). There was no significant difference in SGA or NICU admission. Postpartum hemorrhage increased significantly from 7.7 % to 8.2 % (p=<0.003). Perinatal mortality from 32 weeks onwards was not significantly different after closure 0.29 % to 0.27 %.

CONCLUSIONS

After closure of an obstetric unit in a community hospital in Amsterdam, there was a significant decrease in perinatal, intrapartum and early neonatal mortality in neonates born from 24⁺⁰ onwards. The mortality decrease coincides with a reduction of preterm deliveries. The increasing trend in asphyxia and postpartum hemorrhage is of concern.. Centralization of care and increasing birth volume per hospital may lead to improvement of quality of care. A broad integrated, multidisciplinary maternity healthcare system linked with the social domain can achieve health gains in maternity care for all women.

Cervical pessary for preventing preterm birth in singleton pregnancies

BACKGROUND

Preterm birth (PTB), defined as birth prior to 37 weeks of gestation, occurs in ten percent of all pregnancies. PTB is responsible for more than half of neonatal and infant mortalities and morbidities. Because cervical insufficiency is a common cause of PTB, one possible preventive strategy involves insertion of a cervical pessary to support the cervix. Several published studies have compared the use of pessary with different management options and obtained questionable results. This highlights the need for an up-to-date systematic review of the evidence.

OBJECTIVES

To evaluate the benefits and harms of cervical pessary for preventing preterm birth in women with singleton pregnancies and risk factors for cervical insufficiency compared to no treatment, vaginal progesterone, cervical cerclage or bedrest.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform to 22 September 2021. We also searched the reference lists of included studies for additional records.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials (RCTs) comparing cervical pessary with no treatment, vaginal progesterone, cervical cerclage or bedrest for preventing PTB. We excluded quasi-randomised trials. Our primary outcome was delivery before 34 weeks' gestation. Our secondary outcomes were 1. delivery before 37 weeks' gestation, 2. maternal mortality, 3. maternal infection or inflammation, 4. preterm prelabour rupture of membranes, 5. harm to woman from the intervention, 6. maternal medications, 7. discontinuation of the intervention, 8. maternal satisfaction, 9. neonatal/paediatric care unit admission, 10. fetal/infant mortality, 11. neonatal sepsis, 12. gestational age at birth, 13. harm to offspring from the intervention 14. birthweight, 15. early neurodevelopmental morbidity, 15. late neurodevelopmental morbidity, 16. gastrointestinal morbidity and 17. respiratory morbidity.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for eligibility and risk of bias, evaluated trustworthiness based on criteria developed by the Cochrane Pregnancy and Childbirth Review Group, extracted data, checked for accuracy and assessed certainty of evidence using the GRADE approach.

MAIN RESULTS

We included eight RCTs (2983 participants). We included five RCTs (1830 women) in the comparison cervical pessary versus no treatment, three RCTs (1126 pregnant women) in the comparison cervical pessary versus vaginal progesterone, and one study (13 participants) in the comparison cervical pessary versus cervical cerclage. Overall, the certainty of evidence was low to moderate due to inconsistency (statistical heterogeneity), imprecision (few events and wide 95% confidence intervals (CIs) consistent with possible benefit and harm), and risk of performance and detection bias. Cervical pessary versus no treatment Cervical pessary compared with no treatment may reduce the risk of delivery before 34 weeks (risk ratio (RR) 0.72, 95% CI 0.33 to 1.55; 5 studies, 1830 women; low-certainty evidence) or before 37 weeks (RR 0.68, 95% CI 0.44 to 1.05; 5 studies, 1830 women; low-certainty evidence). However, these results should be viewed with caution because the 95% CIs cross the line of no effect. Cervical pessary compared with no treatment probably has little or no effect on the risk of maternal infection or inflammation (RR 1.04, 95% CI 0.87 to 1.26; 2 studies, 1032 women; moderate-certainty evidence). It is unclear if cervical pessary compared with no treatment has an effect on neonatal/paediatric care unit admission (RR 0.96, 95% CI 0.58 to 1.59; 3 studies, 1332 infants; low-certainty evidence) or fetal/neonatal mortality (RR 0.93, 95% CI 0.58 to 1.48; 5 studies, 1830 infants; low-certainty evidence) because the 95% CIs are compatible with a wide range of effects that encompass both appreciable benefit and harm. Cervical pessary versus vaginal progesterone Cervical pessary may reduce the risk of delivery before 34 weeks (RR 0.72, 95% CI 0.52 to 1.02; 3 studies, 1126 women; moderate-certainty evidence) or before 37 weeks (RR 0.89, 95% CI 0.73 to 1.09; 3 studies, 1126 women; moderate-certainty evidence), but we are uncertain of the results because the 95% CI crosses the line of no effect. The intervention probably has little or no effect on maternal infection or inflammation (RR 0.95, 95% CI 0.81 to 1.12; 2 studies, 265 women; moderate-certainty evidence). It is unclear if cervical pessary compared with vaginal progesterone has an effect on the risk of neonatal/paediatric care unit admission (RR 0.98, 95% CI 0.49 to 1.98; low-certainty evidence) or fetal/neonatal mortality (RR 1.97, 95% CI 0.50 to 7.70; 2 studies; 265 infants; low-certainty evidence) because the 95% CIs are compatible with a wide range of effects that encompass both appreciable benefit and harm. Cervical pessary versus cervical cerclage Only one very small study of 13 pregnant women contributed data to this comparison; the results were unclear.

AUTHORS' CONCLUSIONS

In women with a singleton pregnancy, cervical pessary compared with no treatment or vaginal progesterone may reduce the risk of delivery before 34 weeks or 37 weeks, although these results should be viewed with caution due to uncertainty around the effect estimates. There is insufficient evidence with regard to the effect of cervical pessary compared with cervical cerclage on PTB. Due to low certainty-evidence in many of the prespecified outcomes and non-reporting of several other outcomes of interest for this review, there is a need for further robust RCTs that use standardised terminology for maternal and offspring outcomes. Future trials should take place in a range of settings to improve generalisability of the evidence. Further research should concentrate on comparisons of cervical pessary versus cervical cerclage and bed rest. Investigation of different phenotypes of PTB may be relevant.

FIGO good practice recommendations on cervical cerclage for prevention of preterm birth

Cervical cerclage is an intervention which when given to the right women can prevent preterm birth and second‐trimester fetal losses. A history‐indicated cerclage should be offered to women who have had three or more preterm deliveries and/or mid‐trimester losses. An ultrasound‐indicated cerclage should be offered to women with a cervical length <25 mm if they have had one or more spontaneous preterm birth and/or mid‐trimester loss. In high‐risk women who have not had a previous mid‐trimester loss or preterm birth, an ultrasound‐indicated cerclage does not have a clear benefit in women with a short cervix. However, for twins, the advantage seems more likely at shorter cervical lengths (<15 mm). In women who present with exposed membranes prolapsing through the cervical os, a rescue cerclage can be considered on an individual case basis, taking into account the high risk of infective morbidity to mother and baby. An abdominal cerclage can be offered in women who have had a failed cerclage (delivery before 28 weeks after a history or ultrasound‐indicated [but not rescue] cerclage). If preterm birth has not occurred, removal is considered at 36–37 weeks in women anticipating a vaginal delivery.

Cervical cerclage given to the right women can prevent preterm birth and second‐trimester fetal losses.

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low‐risk and unselected populations

This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:

The main objectives of this review are to assess the diagnostic accuracy of first‐ and second‐trimester fetal anomaly screening in low‐risk pregnant women, and to compare overall performance of single‐ and two‐stage screening approaches with regards to the number of cases detected before birth, as well as the proportion of false positive diagnoses.

Effect of adjunctive vaginal progesterone after McDonald cerclage on the rate of second-trimester abortion in singleton pregnancy: a randomized controlled trial

OBJECTIVE

To evaluate the effect of adjunctive use of vaginal progesterone after McDonald cerclage on the rate of second-trimester abortion in singleton pregnancy.

METHODS

A randomized controlled trial at Woman's Health Hospital, Assiut University, Egypt, between April 2017 and March 2019 enrolled women eligible for McDonald cerclage. After cerclage, participants were randomly assigned to receive progesterone (400 mg pessary) once daily until 37 weeks or no progesterone. The primary outcome was rate of abortion before 28 weeks. Secondary outcomes included gestational age at delivery, preterm delivery, mean birthweight, Apgar score, and admission to the neonatal intensive care unit (NICU).

RESULTS

The rate of spontaneous abortion was higher in the no-progesterone group (P=0.016). Mean gestational age and mean birthweight was higher in the progesterone group (P<0.001 and P=0.002, respectively). The frequency of preterm neonates, neonates with Apgar score less than 7, and admission to NICU was higher in the progesterone group than in the no-progesterone group (P=0.005, P=0.008, and P=0.044, respectively).

CONCLUSION

Adjunctive use of vaginal progesterone after McDonald cerclage was found to decrease the frequency of second-trimester abortion and to improve perinatal outcomes in singleton pregnancy. Clinicaltrials.gov: NCT02846909.

Cervical pessary for preventing preterm birth in singletons and twin pregnancies: an update systematic review and meta-analysis

Objectives: To evaluate the effectiveness of cervical pessary in preventing preterm birth (PTB) and improving perinatal outcomes among singleton and twin pregnancies.Methods: Electronic databases were systematically searched from their inception until 14 March 2019. Randomized clinical trials comparing the effectiveness of cervical pessary placement with expectant management were included. The primary outcome was the incidence of PTB <34 weeks.Results: Thirteen studies were included, involving eight studies about singleton and six studies about twin pregnancies. For singleton pregnancies with short cervical length, cervical pessary, comparing with expectant treatment, seemed have no effectiveness in preventing PTB <34 weeks (relative risk, 95% confidence interval, 0.73, 0.42-1.28), <37 weeks (0.69, 0.43-1.09), and <28 weeks (0.79, 0.42-1.48); while for twin pregnancies with short cervical length, cervical pessary also did not reduce the risk of PTB <34 weeks (0.81, 0.49-1.35), <37 weeks (0.93, 0.83-1.05), and <28 weeks (0.72, 0.38-1.38). However, cervical pessary seemed have the effectiveness of reducing the risk of spontaneous PTB <28 weeks (0.50, 0.25-0.99) and low birth weight (<1500 g) (0.68, 0.50-0.94) among twin pregnancies with short cervical length. In addition, cervical pessary increased the rate of vaginal discharge and did not improve perinatal outcomes among both singleton and twin pregnancies.Conclusions: Comparing with the expectant treatment, the effectiveness of cervical pessary for reducing the risk of PTB remains uncertain. Additional trials are warranted to further evaluate the effectiveness of cervical pessary.

Prevention of Prematurity: Advances and Opportunities

Preterm birth (PTB) rate varies widely and has significant racial and ethnic disparities. Although causal mechanisms are ill understood, socioenvironment, phenotype, and genotype provide insight into pathways for preventing PTB. Data suggest varied response to current medical interventions is explicable Approved by underlying pharmacogenomics. Currently, prevention focuses on minimizing iatrogenic PTB and risk reduction especially in those with prior PTB using proven medical and public health strategies. In the future, preventive approaches will be based on better understanding of sociodemography, nutrition, lifestyles, and underlying individual genetic and epigenetic variation. Statistical approaches and "big-data" models are critical in future study.