Cervical pessary versus vaginal progesterone in women with a singleton pregnancy, a short cervix, and no history of spontaneous preterm birth at less than 34 weeks' gestation: open label, multicentre, randomised, controlled trial

OBJECTIVE

To compare the effectiveness of cervical pessary and vaginal progesterone in the prevention of adverse perinatal outcomes and preterm birth in pregnant women of singletons with no prior spontaneous preterm birth at less than 34 weeks' gestation and who have a short cervix of 35 mm or less.

DESIGN

Open label, multicentre, randomised, controlled trial.

SETTING

20 hospitals and five obstetric ultrasound practices in the Netherlands.

PARTICIPANTS

Women with a healthy singleton pregnancy and an asymptomatic short cervix of 35 mm or less between 18 and 22 weeks' gestation were eligible. Exclusion criteria were prior spontaneous preterm birth at less than 34 weeks, a cerclage in situ, maternal age of younger than 18 years, major congenital abnormalities, prior participation in this trial, vaginal blood loss, contractions, cervical length of less than 2 mm or cervical dilatation of 3 cm or more. Sample size was set at 628 participants.

INTERVENTIONS

1:1 randomisation to an Arabin cervical pessary or vaginal progesterone 200 mg daily up to 36 weeks' of gestation or earlier in case of ruptured membranes, signs of infection, or preterm labour besides routine obstetric care.

MAIN OUTCOME MEASURES

Primary outcome was a composite adverse perinatal outcome. Secondary outcomes were rates of (spontaneous) preterm birth at less than 28, 32, 34, and 37 weeks. A predefined subgroup analysis was planned for cervical length of 25 mm or less.

RESULTS

From 1 July 2014 to 31 March 2022, 635 participants were randomly assigned to pessary (n=315) or to progesterone (n=320). 612 were included in the intention to treat analysis. The composite adverse perinatal outcome occurred in 19 (6%) of 303 participants with a pessary versus 17 (6%) of 309 in the progesterone group (crude relative risk 1.1 (95% confidence interval (CI) 0.60 to 2.2)). The rates of spontaneous preterm birth were not significantly different between groups. In the subgroup of cervical length of 25 mm or less, spontaneous preterm birth at less than 28 weeks occurred more often after pessary than after progesterone (10/62 (16%) v 3/69 (4%), relative risk 3.7 (95% CI 1.1 to 12.9)) and adverse perinatal outcomes seemed more frequent in the pessary group (15/62 (24%) v 8/69 (12%), relative risk 2.1 (0.95 to 4.6)).

CONCLUSIONS

In women with a singleton pregnancy with no prior spontaneous preterm birth at less than 34 weeks' gestation and with a midtrimester short cervix of 35 mm or less, pessary is not better than vaginal progesterone. In the subgroup of a cervical length of 25 mm or less, a pessary seemed less effective in preventing adverse outcomes. Overall, for women with single baby pregnancies, a short cervix, and no prior spontaneous preterm birth less than 34 weeks' gestation, superiority of a cervical pessary compared with vaginal progesterone to prevent preterm birth and consecutive adverse outcomes could not be proven.

TRIAL REGISTRATION

International Clinical Trial Registry Platform (ICTRP, EUCTR2013-002884-24-NL).

The Risk of Preterm Birth in Low Risk Pregnant Women with Urinary Tract Infections

OBJECTIVE

Urinary tract infections are among the most common infections during pregnancy. The association between symptomatic lower urinary tract infections during pregnancy and fetal and maternal complications such as preterm birth and low birthweight remains unclear. The aim of this research is to evaluate the association between urinary tract infections during pregnancy and maternal and neonatal outcomes, especially preterm birth.

STUDY DESIGN

This study is a secondary analysis of a multicenter prospective cohort study, which included patients between October 2011 and June 2013. The population consists of women with low risk singleton pregnancies. We divided the cohort into women with and without a symptomatic lower urinary tract infection after 20 weeks of gestation. Baseline characteristics and maternal and neonatal outcomes were compared between the two groups. Multivariable logistic regression analysis was used to correct for confounders. The main outcome was spontaneous preterm birth at <37 weeks.

RESULTS

We identified 4,918 pregnant women eligible for enrollment, of whom 9.4% had a symptomatic lower urinary tract infection during their pregnancy. Women with symptomatic lower urinary tract infections were at increased risk for both preterm birth in general (12 vs. 5.1%, adjusted OR 2.5; 95% CI 1.7-3.5) as well as a spontaneous preterm birth at <37 weeks (8.2 vs. 3.7%, adjusted OR 2.3; 95% CI 1.5-3.5). This association was also present for early preterm birth at <34 weeks. Women with symptomatic lower urinary tract infections during pregnancy are also at increased risk of endometritis (8.9 vs. 1.8%, adjusted OR 5.3; 95% CI 1.4-20) and mastitis (7.8 vs. 1.8%, adjusted OR 4.0; 95% CI 1.6-10) postpartum.

CONCLUSION

Low risk women with symptomatic lower urinary tract infections during pregnancy are at increased risk of spontaneous preterm birth. In addition, an increased risk for endometritis and mastitis postpartum was found in women with symptomatic lower urinary tract infection during pregnancy.

KEY POINTS

· UTIs increase the risk of preterm birth.. · UTIs increase the risk of endometritis postpartum.. · UTIs increase the risk of mastitis postpartum..

Changes in the Prevalence of Infection in Pregnant Women during the COVID-19 Lockdown

BACKGROUND

During the outbreak of SARS-CoV-2, strict mitigation measures and national lockdowns were implemented. Our objective was to investigate to what extent the prevalence of some infections in pregnancy was altered during different periods of the COVID-19 pandemic.

METHODS

This was a single centre retrospective cohort study conducted in the Netherlands on data collected from electronic patient files of pregnant women from January 2017 to February 2021. We identified three time periods with different strictness of mitigation measures: the first and second lockdown were relatively strict; the inter-lockdown period was less strict. The prevalence of the different infections (Group B Streptococcus (GBS)-carriage, urinary tract infections and Cytomegalovirus infection) during the lockdown was compared to the same time periods in previous years (2017-2019).

RESULTS

In the first lockdown, there was a significant decrease in GBS-carriage (19.5% in 2017-2019 vs. 9.1% in 2020; p = 0.02). In the period following the first lockdown and during the second, no differences in prevalence were found. There was a trend towards an increase in positive Cytomegalovirus IgM during the inter-lockdown period (4.9% in 2017-2019 vs. 12.8% in 2020; p = 0.09), but this did not reach statistical significance. The number of positive urine cultures did not significantly change during the study period.

CONCLUSIONS

During the first lockdown there was a reduction in GBS-carriage; further studies are warranted to look into the reason why.

Perioperative complications of a transvaginal cervical cerclage in singleton pregnancies: a systematic review and meta-analysis

OBJECTIVE

Given that many studies report on a limited spectrum of adverse events of transvaginal cervical cerclage for preventing preterm birth, but are not powered to draw conclusions about its safety, the objective of this study was to conduct a systematic review with pooled risk analyses of perioperative complications and compare characteristics on the basis of indication for cerclage in singleton pregnancies.

DATA SOURCES

Ovid MEDLINE, Ovid Embase, Web of Science, the Cochrane Central Register of Controlled Trials (CENTRAL), and the prospective trial registers ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched from inception to April 2020.

STUDY ELIGIBILITY CRITERIA

All randomized controlled trials and both retrospective and prospective observational cohort studies reporting about complications in history-indicated cerclage, ultrasound-indicated cerclage, or physical examination-indicated cerclage were eligible. Studies were included if they contained original data on the occurrence of adverse events during surgery or within 24 hours after surgery.

METHODS

The Cochrane risk of bias tool for randomized controlled trials and the Newcastle-Ottawa scale for cohort and case-control studies were used for the critical appraisal. The pooled risk assessment was conducted using meta and metafor packages in R (studio), version 4.0.3.

RESULTS

The search yielded 2328 potential studies; 3 randomized controlled trials, 3 prospective, and 38 retrospective cohort studies were included in the final analysis. Of the 4511 women with singleton gestations, 1561 (34.6%) underwent history-indicated cerclage, 1348 (29.9%) underwent ultrasound-indicated cerclage, and 1549 (33.3%) underwent physical examination-indicated cerclage. Most perioperative complications occurred in physical examination-indicated cerclage, especially hemorrhage (2.3%; 95% confidence interval, 0.0-7.6) and preterm premature rupture of membranes (2.5%; 95% confidence interval, 0.91-4.5). The fewest complications occurred in history-indicated cerclage, varying from 0.0% of preterm premature rupture of membranes (95% confidence interval, 0.0-1.7) to 0.9% of hemorrhage (95% confidence interval, 0.0-7.9). In ultrasound-indicated cerclage, the most common complication was hemorrhage (1.4%; 95% confidence interval, 0.0-4.1), followed by lacerations (0.6%; 95% confidence interval, 0.0-3.1) and preterm premature rupture of membranes (0.3%; 95% confidence interval, 0.0-0.8).

CONCLUSION

The highest risk of perioperative complications was observed in physical examination-indicated cerclage in comparison with ultrasound- and history-indicated cerclage. However, the occurrence of complications is poorly documented in the published literature, as is the timing of the complications (ie, perioperative or later in pregnancy). There is an urgent need for uniform complication reporting policy in both cohort studies and randomized controlled trials on cerclage.

Diagnostic work-up of urinary tract infections in pregnancy: study protocol of a prospective cohort study

INTRODUCTION

Symptoms of urinary tract infections in pregnant women are often less specific, in contrast to non-pregnant women where typical clinical symptoms of a urinary tract infection are sufficient to diagnose urinary tract infections. Moreover, symptoms of a urinary tract infection can mimic pregnancy-related symptoms, or symptoms of a threatened preterm birth, such as contractions. In order to diagnose or rule out a urinary tract infection, additional diagnostic testing is required.The diagnostic accuracy of urine dipstick analysis and urine sediment in the diagnosis of urinary tract infections in pregnant women has not been ascertained nor validated.

METHODS AND ANALYSIS

In this single-centre prospective cohort study, pregnant women (≥16 years old) with a suspected urinary tract infection will be included. The women will be asked to complete a short questionnaire regarding complaints, risk factors for urinary tract infections and baseline characteristics. Their urine will be tested with a urine dipstick, urine sediment and urine culture. The different sensitivities and specificities per test will be assessed. Our aim is to evaluate and compare the diagnostic accuracy of urine dipstick analysis and urine sediment in comparison with urine culture (reference test) in pregnant women. In addition, we will compare these tests to a predefined 'true urinary tract infection', to distinguish between a urinary tract infection and asymptomatic bacteriuria.

ETHICS AND DISSEMINATION

Approval was requested from the Medical Ethics Review Committee of the Academic Medical Centre; an official approval of this study by the committee was not required. The outcomes of this study will be published in a peer-reviewed journal.

Uniform international method to measure cervical length; are we there yet?

INTRODUCTION

Cervical length is an important predictor of spontaneous preterm birth. So far, the best way to measure cervical length has not been established. We aimed to compare the incidence of short cervical length between three methods of cervical length measurement with and without inclusion of cervico-isthmic complex (CIC) (six methods in total) and to determine the positive predictive value for spontaneous preterm birth.

MATERIAL AND METHODS

We performed a prospective single center cohort study in women with a singleton pregnancy between August 2014 and December 2018. During the routine fetal anomaly scan (18-22 weeks), women were offered transvaginal ultrasound for cervical length measurement to screen for the risk of spontaneous preterm birth. Each cervix was measured in six different ways: single-line, two-line and tracing method between the internal and external os of the cervix with and without CIC. We evaluated the predictive value of the different measurements for spontaneous delivery before 37 weeks using positive predictive values.

RESULTS

Our final study population comprised 1,691 women. The overall rate of preterm birth < 37 weeks was 8.0% (4.6% spontaneous, 3.4% iatrogenic preterm birth). The mean gestational age was 19+6 weeks. The different techniques resulted in significant different cervical lengths, showing a maximum difference of > 8 mm between the techniques (41.04 mm (SD 7.1) with one-line without CIC and 49.18 (SD 9.05) mm with trace with CIC) with an incidence of short cervical length below < 25mm ranging from 0.4 to 1.1% (P=0.18). The positive predictive values for spontaneous preterm birth < 37 weeks ranged from 42.9 to 20.0% .

CONCLUSION

Different measurement methods for cervical length resulted in statistically significant differences in measured cervical length. Depending on the chosen cut-off this translates to different incidences of short cervical length, and influences the number of women designated as high risk for preterm birth and receiving treatment. For interpretation and comparability between (inter-)national studies, it is important to adequately report on the employed technique.

Risk of preterm birth for placenta previa or low-lying placenta and possible preventive interventions: A systematic review and meta-analysis

OBJECTIVE

To investigate the risk of preterm birth in women with a placenta previa or a low-lying placenta for different cut-offs of gestational age and to evaluate preventive interventions.

SEARCH AND METHODS

MEDLINE, EMBASE, CENTRAL, Web of Science, WHO-ICTRP and clinicaltrials.gov were searched until December 2021. Randomized controlled trials, cohort studies and case-control studies assessing preterm birth in women with placenta previa or low-lying placenta with a placental edge within 2 cm of the internal os in the second or third trimester were eligible for inclusion. Pooled proportions and odds ratios for the risk of preterm birth before 37, 34, 32 and 28 weeks of gestation were calculated. Additionally, the results of the evaluation of preventive interventions for preterm birth in these women are described.

RESULTS

In total, 34 studies were included, 24 reporting on preterm birth and 9 on preventive interventions. The pooled proportions were 46% (95% CI [39 - 53%]), 17% (95% CI [11 - 25%]), 10% (95% CI [7 - 13%]) and 2% (95% CI [1 - 3%]), regarding preterm birth <37, <34, <32 and <28 weeks in women with placenta previa. For low-lying placentas the risk of preterm birth was 30% (95% CI [19 - 43%]) and 1% (95% CI [0 - 6%]) before 37 and 34 weeks, respectively. Women with a placenta previa were more likely to have a preterm birth compared to women with a low-lying placenta or women without a placenta previa for all gestational ages. The studies about preventive interventions all showed potential prolongation of pregnancy with the use of intramuscular progesterone, intramuscular progesterone + cerclage or pessary.

CONCLUSIONS

Both women with a placenta previa and a low-lying placenta have an increased risk of preterm birth. This increased risk is consistent across all severities of preterm birth between 28-37 weeks of gestation. Women with placenta previa have a higher risk of preterm birth than women with a low-lying placenta have. Cervical cerclage, pessary and intramuscular progesterone all might have benefit for both women with placenta previa and low-lying placenta, but data in this population are lacking and inconsistent, so that solid conclusions about their effectiveness cannot be drawn.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO https://www.crd.york.ac.uk/prospero/, identifier CRD42019123675.

Differences in clinical practice regarding screening and treatment of infections associated with spontaneous preterm birth: An international survey

OBJECTIVE

An association between infections in pregnancy and increased risk of preterm birth (PTB) is described in the literature. We anticipated that differences may exist in screening and treatment approaches for infections associated with PTB, within and between European countries. The aim of this study was to examine and analyse these differences in clinical practice in greater detail.

STUDY DESIGN

We created a descriptive survey examining the screening and treatment of infections in pregnancy. The survey was sent to European representatives of the International Spontaneous Preterm Birth Young Investigators (I-SPY) group in Europe, who sent it to their network. Finally, we had 50 respondents from ten European countries.

RESULTS

We found substantial differences in screening for bacterial vaginosis and asymptomatic bacteriuria, administration of antibiotics to women with preterm prelabour rupture of membranes (PPROM), and timing of induction of labour after PPROM. These differences in clinical practice were present both within, and between countries.

CONCLUSIONS

Approaches for screening and treatment of infections associated with PTB differ between European countries. There is a lack of robust evidence, which is reflected in a lack of uniformity in international guidelines. International collaboration is paramount to enlarge sample sizes in obstetric studies and to facilitate the process of developing, updating, and implementing consistent guidelines across Europe and beyond.

Ethnic differences in the impact of male fetal gender on the risk of spontaneous preterm birth

OBJECTIVE

To study the impact of fetal gender on the risk of spontaneous preterm birth in various ethnicities.

STUDY DESIGN

National cohort study in which all singleton live births from 25⁺⁰ weeks onwards without congenital anomalies were included of African, Asian, and Mediterranean women (1999-2010). Our primary outcome measure was preterm birth before 37 weeks. Per ethnic group, male and female neonates were compared.

RESULT

In each ethnic group, male fetuses were at increased risk of preterm birth (adjusted odds ratio (aOR) 1.63 for African, aOR 1.71 for Asian, and aOR 1.84 for Mediterranean males). The population-attributable risk of male gender on spontaneous preterm birth is lower in African women (3.9%) than in Asian (10.3%) and Mediterranean women (9.0%).

CONCLUSION

Male fetal gender is associated with spontaneous preterm birth in African, Asian, and Mediterranean women, but the total impact of ethnicity on spontaneous preterm birth rate is different.

Maternal, perinatal and childhood outcomes of the PPROMEXIL-III cohort: Pregnancies complicated by previable prelabor rupture of membranes

OBJECTIVE

Perinatal mortality after previable prelabor rupture of membranes (previable PROM) might be underestimated as most studies exclude patients with poor prognosis, or solely include patients in tertiary-care centers. We aimed to report perinatal, neonatal and long-term outcomes in a consecutive series of women with pregnancies complicated by previable PROM.

STUDY DESIGN

We conducted a prospective cohort study including women with singleton pregnancies and previable PROM ≤ 23⁺⁶ weeks gestational age (GA) from one tertiary hospital and eight affiliated secondary hospitals in the region of Amsterdam, the Netherlands (June 2012 until January 2016, PPROMEXIL-III cohort). Exclusion criteria were signs of active labor before onset of PROM or fetal structural anomalies visible at ultrasound. We assessed perinatal mortality. Furthermore, outcomes were maternal, perinatal, neonatal and long-term child characteristics.

RESULTS

We included 98 pregnancies with previable PROM. Twelve women (12.2%) opted for termination of pregnancy, resulting in 86 pregnancies included in further analyses. Median GA at PROM was 20⁺² weeks (interquartile range (IQR) 17⁺⁶-22⁺⁰). Median GA at delivery was 22⁺⁶ weeks (IQR 20⁺¹-26⁺⁴). Delivery within 1 week occurred in 38.4% of women and 60.4% delivered before 24 weeks GA (viability). Perinatal mortality occurred in 73.3% of pregnancies. 23/33 (69.7%) live-born neonates survived to discharge, representing 26.7% of total. None of the children died after discharge. Developmental data at two and/or five years of age was available for 13/23 children (i.e. all children born before 32 weeks of gestation), with 69.2% of children reporting a normal neurodevelopment. However, more than half of children reported respiratory problems.

CONCLUSION

In women with previable PROM perinatal mortality was 73.3%, with a normal neurodevelopment in 69.2% of surviving children with follow-up data. Due to broad inclusion criteria, this cohort represents a population more generalizable to daily practice as compared to previous studies.

The association between depressive symptoms during pregnancy and post-delivery fear of childbirth; a prospective study

BACKGROUND

Fear of childbirth is an important reason for a caesarean section on request.

OBJECTIVE

To assess the association between depressive symptoms during pregnancy and post-delivery fear of childbirth (PFOC).

METHODS

We prospectively studied pregnant women from two hospitals in the Netherlands. Women completed the Edinburgh Depression Scale (EPDS), the Wijma Delivery Experience Questionnaire (W-DEQ B) and questions concerning risk factors. Depressive symptoms were assessed at baseline and six weeks post-delivery. PFOC was assessed six weeks post-delivery. Baseline characteristics and pregnancy outcomes were compared between women with and without a depression at baseline. The association between depression and PFOC was assessed with multivariable logistic regression analysis.

RESULTS

245 women participated in this study. At baseline 11% suffered from depressive symptoms. There were no differences in pregnancy outcomes. Women with depressive symptoms more often suffered from depressive symptoms six weeks post-delivery (adjusted OR 4.9, 95% CI 1.4-17). PFOC six weeks post-delivery was present in 11%. Women with depression were at increased risk of PFOC six weeks post-delivery (adjusted OR 9.2, 95% CI 2.6-32).

CONCLUSION

This study shows that women with depression at baseline are at increased risk for depression and PFOC six weeks post-delivery.

The association between parity and spontaneous preterm birth: a population based study

Background

Preterm birth is the leading cause of perinatal mortality and neonatal morbidity worldwide. Many factors have been associated with preterm birth, including parity. The aim of the present study was to investigate associations between parity and risk of spontaneous preterm birth.

Methods

We conducted a retrospective study including live singleton births (≥22 weeks) of women with a first, second, third, fourth or fifth pregnancy in The Netherlands from 2010 through 2014. Our primary outcome was risk of spontaneous preterm birth < 37 weeks. Secondary outcomes were spontaneous preterm birth < 32 and < 28 weeks.

Results

We studied 802,119 pregnancies, including 30,237 pregnancies that ended spontaneously < 37 weeks. We identified an increased risk for spontaneous preterm birth < 37 weeks in nulliparous women (OR 1.95, 95% CI 1.89–2.00) and women in their fifth pregnancy (OR 1.26, 95% CI 1.13–1.41) compared to women in their second pregnancy. Similar results were seen for spontaneous preterm birth < 32 and < 28 weeks.

Conclusion

Our data show an independent association between nulliparity and spontaneous preterm birth < 37, < 32 and < 28 weeks. Furthermore, we observed an increased risk for spontaneous preterm birth in women in their fifth pregnancy, with highest risk for preterm birth at early gestational age.

Risk of adverse pregnancy outcomes of late- and postterm pregnancies in advanced maternal age: A national cohort study

Introduction

There is an increase in women delivering ≥35 years of age. We analyzed the association between advanced maternal age and pregnancy outcomes in late‐ and postterm pregnancies.

Material and methods

A national cohort study was performed on obstetrical low‐risk women using data from the Netherlands Perinatal Registry from 1999 to 2010. We included women ≥18 years of age with a singleton pregnancy at term. Women with a pregnancy complicated by congenital anomalies, hypertensive disorders or diabetes mellitus were excluded. Composite adverse perinatal outcome was defined as stillbirth, neonatal death, meconium aspiration syndrome, 5‐minute Apgar score <7, neonatal intensive care unit admittance and sepsis. Composite adverse maternal outcome was defined as maternal death, placental abruption and postpartum hemorrhage of >1000 mL.

Results

We stratified the women into three age groups: 18‐34 (n = 1 321 366 [reference]); 35‐39 (n = 286 717) and ≥40 (n = 40 909). Composite adverse perinatal outcome occurred in 1.6% in women aged 18‐34, 1.7% in women aged 35‐39 (relative risk [RR] 1.06, 95% confidence interval [95% CI] 1.03‐1.08) and 2.2% in women aged ≥40 (RR 1.38, 95% CI 1.29‐1.47), with 5‐minute Apgar score <7 as the factor contributing most to the outcome. Composite adverse maternal outcome occurred in 4.6% in women aged 18‐34, 5.0% in women aged 35‐39 (RR 1.08, 95% CI 1.06‐1.10) and 5.2% in women aged ≥40 (RR 1.14, 95% CI 1.09‐1.19), with postpartum hemorrhage >1000 mL as the factor contributing most to the outcome. In all age categories, the risk of adverse pregnancy outcomes was higher for nulliparous than for multiparous women. The risk of adverse outcomes increased in both nulliparous and parous women with advancing gestational age. When adjusted for parity, onset of labor and gestational age, advanced maternal age is associated with an increase in both composite adverse perinatal and maternal outcomes.

Conclusions

The risk of adverse pregnancy outcome increases with advancing maternal age. Women aged ≥40 have an increased risk of adverse perinatal and maternal outcome when pregnancy goes beyond 41 weeks.

Is asymptomatic bacteriuria associated with short cervical length in women with a singleton pregnancy, a secondary analysis of two national cohort studies with small embedded randomized controlled trials

OBJECTIVE

To assess the association between asymptomatic bacteriuria (ASB) and short cervical length (CL), since they are both associated with preterm delivery.

STUDY DESIGN

In two prospective multicentre cohort studies, pregnant women were screened for the presence of ASB and short CL (≤25 mm). We compared CL in women with and without ASB. Both studies had a small randomised clinical trial embedded.

RESULTS

Our study population comprised 1 610 women, of whom 114 were ASB positive. Median cervical length was similar in women with and without ASB (44.0 vs 44.0 mm, P = 0.60). More women in the ASB positive group had a short CL compared to the ASB negative group (1.8 % versus 0.4 %, P = 0.047)). The gestational age at delivery did not differ between the groups (ranging from 38 + 3 in women with ASB and short CL to 39 + 5 in women without ASB with a short CL P = 0.52). No preterm births occurred in women with a short cervical length (regardless of ASB status). In the women without ASB and no short CL 4.8 % had a preterm birth, in the women with ASB but not a short CL 4.1 % had a preterm birth.

CONCLUSION

While ASB status did not influence median cervical length, we found a significant relationship between a short CL and ASB positive women. We found no statistical significant difference on the preterm birth rate and mean gestational age.

Risk of preterm birth after prior term cesarean

Objective

To determine the risk of overall preterm birth (PTB) and spontaneous PTB in a pregnancy after a caesarean section (CS) at term.

Design

Longitudinal linked national cohort study.

Setting

The Dutch Perinatal Registry (1999–2009).

Population

268 495 women with two subsequent singleton pregnancies were identified.

Methods

A cohort study based on linked registered data from two subsequent pregnancies in the Netherlands.

Main outcome measures

The incidence of overall PTB and spontaneous PTB with subgroup analysis on gestational age at first delivery and type of CS (planned or unplanned).

Results

Of 268 495 women with a singleton first pregnancy who delivered at term, 15.76% (n = 42 328) had a CS. The incidence of PTB in the second pregnancy was 2.79% (n = 1182) in women with a previous CS versus 2.46% (n = 5570) in women with a previous vaginal delivery (adjusted odds ratio [aOR] 1.14, 95% confidence interval [CI] 1.07–1.21). This increased risk is mainly driven by an increased risk of spontaneous PTB after previous CS at term (aOR 1.50, 95% CI 1.38–1.70). Analysis for type of CS compared with vaginal delivery showed an aOR on spontaneous PTB of 1.86 (95% CI 1.58–2.18) for planned CS and an aOR of 1.40 (95% CI 1.24–1.58) for unplanned CS.

Conclusions

CS at term is associated with a marginally increased risk of spontaneous PTB in a subsequent pregnancy.

Tweetable abstract

Caesarean section at term is associated with a marginally increased risk of spontaneous PTB in a subsequent pregnancy.

Caesarean section at term is associated with a marginally increased risk of spontaneous PTB in a subsequent pregnancy.

Trends in preterm birth in singleton and multiple gestations in the Netherlands 2008-2015: A population-based study

OBJECTIVE

Preterm birth is the most important cause of perinatal morbidity and mortality. Over the past years several preventive measures have been studied and implemented. Preterm birth percentage in 2015 in the Netherlands was 6.9 %, according to data from the European Peristat project, reporting on perinatal health in Europe. Various preventive measures might have influenced the incidence and outcome of preterm birth. Our aim was to give an overview of the trends in preterm births for both singleton and multiple gestations in the Netherlands in order to guide future research.

STUDY DESIGN

We studied a nationwide cohort including both singleton and multiple gestations without congenital anomalies between 2008 and 2015. Outcomes were total preterm birth (defined as birth before 37 weeks of gestation), spontaneous and iatrogenic preterm birth < 37 weeks, spontaneous and iatrogenic preterm birth percentages between 34-36 weeks, 32-34 weeks, 28-31 weeks and ≤ 27 weeks using a moving average technique. Trend analysis was performed using the Cochran Armitage test. Singleton and multiple gestations were analyzed separately.

RESULTS

Our final study population comprised 1,303.786 women with a singleton and 44,951 women with a multiple pregnancy. Preterm birth < 37 weeks in singletons decreased from 5.6 % in 2008 to 5.3 % in 2015 (P < 0.0001), in both spontaneous and iatrogenic preterm birth. Preterm birth ≤ 27 weeks increased from 0.40 % to 0.45 % (P for trend <0.0001). The number of multiple gestations decreased over the years, as well as the percentage of multiples conceived through IVF/ICSI. There was an increase in total and iatrogenic preterm birth < 37 weeks from 36.7-38.2% (P < 0.0001) in multiples. The number of multiples <32 decreased, in both the spontaneous and iatrogenic group.

CONCLUSION

In the Netherlands preterm birth risk in singletons decreased between 2008 and 2015 but an increase was noted in preterm birth ≤ 27 weeks. In multiples the total preterm birth risk increased, due to an increase in indicated preterm birth.

The predictive capacity of uterine artery Doppler for preterm birth-A cohort study

Introduction

Mid‐trimester uterine artery resistance measured with Doppler sonography is predictive for iatrogenic preterm birth. In view of the emerging association between hypertensive disease in pregnancy and spontaneous preterm birth, we hypothesized that uterine artery resistance could also predict spontaneous preterm birth.

Material and methods

We performed a cohort study of women with singleton pregnancies. Uterine artery resistance was routinely measured at the 18‐22 weeks anomaly scan. Pregnancies complicated by congenital anomalies or intrauterine fetal death were excluded. We analyzed if the waveform of the uterine artery (no notch, unilateral notch or bilateral notch) was predictive for spontaneous and iatrogenic preterm birth, defined as delivery before 37 weeks of gestation. Furthermore, we assessed whether the uterine artery pulsatility index was associated with the risk of preterm birth.

Results

Between January 2009 and December 2016 we collected uterine Doppler indices and relevant outcome data in 4521 women. Mean gestational age at measurement was 19⁺⁶ weeks. There were 137 (3.0%) women with a bilateral and 213 (4.7%) with a unilateral notch. Mean gestational age at birth was 38⁺⁶ weeks. Spontaneous and iatrogenic preterm birth rates were 5.7% and 4.9%, respectively. Mean uterine artery resistance was 1.12 in the spontaneous preterm birth group compared with 1.04 in the term group (P = 0.004) The risk of preterm birth was increased with high uterine artery resistance (OR 2.9 per unit; 95% CI 2.4‐3.9). Prevalence of spontaneous preterm birth increased from 5.5% in women without a notch in the uterine arteries to 8.0% in women with a unilateral notch and 8.0% in women with a bilateral notch. For iatrogenic preterm birth, these rates were 3.9%, 13.6% and 23.4%, respectively. Likelihood ratios for the prediction of spontaneous preterm birth were 1.6 (95% CI 1.0‐2.6) and 1.9 (95% CI 1.0‐3.5) for unilateral and bilateral notches, respectively, and for iatrogenic preterm birth they were 3.6 (95% CI 2.5‐5.2) and 6.8 (95% CI 4.7‐9.9) for unilateral and bilateral notches, respectively. Of all women with bilateral notching, 31.4% delivered preterm.

Conclusions

Mid‐trimester uterine artery resistance measured at 18‐22 weeks of gestation is a weak predictor of spontaneous preterm birth.

Association between fetal sex, birthweight percentile and adverse pregnancy outcome

Introduction

The objective was to evaluate the association between fetal sex and adverse pregnancy outcome, while correcting for fetal growth and gestational age at delivery.

Material and methods

Data from the Netherlands Perinatal Registry (1999‐2010) were used. The study population comprised all white European women with a singleton delivery between 25⁺⁰ and 42⁺⁶ weeks of gestation. Fetuses with structural or chromosomal abnormalities were excluded. Outcomes were antepartum death, intrapartum/neonatal death (from onset of labor until 28 days after birth), perinatal death (antepartum death or intrapartum/neonatal death), a composite of neonatal morbidity (including infant respiratory distress syndrome, sepsis, necrotizing enterocolitis, meconium aspiration, persistent pulmonary hypertension of the newborn, periventricular leukomalacia, Apgar score <7 at 5 minutes, and intracranial hemorrhage) and a composite adverse neonatal outcome (perinatal death or neonatal morbidity). Outcomes were expressed stratified by birthweight percentile (<p10 [small for gestation], p10‐90 [normal weight], >p90 [large for gestation]) and gestational age at delivery (25⁺⁰‐27⁺⁶, 28⁺⁰‐31⁺⁶, 32⁺⁰‐36⁺⁶, 37⁺⁰‐42⁺⁶ weeks). The association between fetal sex and outcome was assessed using the fetus at risk approach.

Results

We studied 1 742 831 pregnant women. We found no increased risk of antepartum, intrapartum/neonatal and perinatal death in normal weight and large‐for‐gestation males born after 28⁺⁰ weeks compared with females. We found an increased risk of antepartum death among small‐for‐gestation males born after 28⁺⁰ weeks (relative risk [RR] 1.16‐1.40). All males born after 32⁺⁰ weeks of gestation suffered more neonatal morbidity than females regardless of birthweight percentile (RR 1.07‐1.34). Infant respiratory distress syndrome, sepsis, persistent pulmonary hypertension of the newborn, Apgar score <7 at 5 minutes, and intracranial hemorrhage all occurred more often in males than in females.

Conclusions

Small‐for‐gestation males have an increased risk of antepartum death and all males born after 32⁺⁰ weeks of gestation have an increased risk of neonatal morbidity compared with females. In contrast to findings in previous studies we found no increased risk of antepartum, intrapartum/neonatal or perinatal death in normal weight and large‐for‐gestation males born after 28+0 weeks.

Large-for-gestational-age fetuses have an increased risk for spontaneous preterm birth

OBJECTIVE

Our aim was to investigate the association between large-for-gestational-age and the risk of spontaneous preterm birth.

STUDY DESIGN

We studied nulliparous women with a singleton gestation using data from the Dutch perinatal registry from 1999 to 2010. Neonates were categorized according to the Hadlock fetal weight standard, into 10th to 90th percentile, 90th to 97th percentile, or above 97th percentile. Outcomes were preterm birth <37⁺⁰ weeks and preterm birth between 25⁺⁰-27⁺⁶ weeks, 28⁺⁰-30⁺⁶ weeks, 31⁺⁰-33⁺⁶ weeks, and 34⁺⁰-36⁺⁶ weeks.

RESULTS

We included 547,418 women. The number of spontaneous preterm births <37 weeks was significantly increased in the large-for-gestational-age group ( > p97) compared with fetuses with a normal growth (p10-p90) (11.3% vs. 7.3%, odds ratio (OR) 1.8; 95% CI 1.7-1.9). The same results were found when limiting analyses to women with certain pregnancy duration (after in vitro fertilization).

CONCLUSION

Large-for-gestational-age increases the risk of spontaneous preterm delivery from 25 weeks of gestation onwards.

Women with a Preterm Cesarean Have High Rates of Successful Trial of Labor in a Subsequent Term Pregnancy

OBJECTIVE

The rate of cesareans has increased worldwide. Therefore, an increasing number of women has to decide how to deliver in a subsequent pregnancy. Individualized information on risks and success chances is helpful. This study investigates the effect of a preterm cesarean on success of subsequent term trial of labor.

STUDY DESIGN

Ten-year Dutch cohort (2000-2009) of women with one previous cesarean and a subsequent term trial of labor. Subgroups were made based on gestational age at first cesarean delivery (25-28, 28-30, 30-32 and 32-34 weeks) and stratified based the way in which second delivery started. Rates of vaginal deliveries, maternal, and neonatal outcomes were compared with women who had a first-term cesarean (37-43 weeks).

RESULTS

Four thousand three-hundred forty-two women delivered by preterm cesarean in the first pregnancy. These women had high rates of successful trial of labor, both after spontaneous onset (86.2-96.2%) and induction (72.8-75.4%). Rates of adverse outcomes were low and similar compared with women with a previous term cesarean.

CONCLUSION

In this 10-year nationwide cohort, women with a preterm first cesarean who opted for trial of labor in a subsequent pregnancy had high rates of successful trial of labor.

Repeated cervical length measurements for the verification of short cervical length

OBJECTIVE

To determine if the verification of short cervical length with a repeated measurement improved the identification of patients with short cervical length at increased risk of preterm delivery.

METHODS

The present secondary analysis analyzed prospective cohort study data from patients with singleton pregnancies without a history of preterm delivery who presented for obstetric care in the Netherlands and delivered between November 18, 2009, and January 1, 2013. Cervical length was measured during standard anomaly scan and a second measurement was performed if the cervical length was 30 mm of shorter. Logistic regression and Cox proportional hazards modeling were used to evaluate associations between cervical length measurements and spontaneous preterm delivery before 37 weeks of pregnancy.

RESULTS

Cervical length measurements from 12 358 patients were included; 221 (1.8%) had an initial cervical length measurement of 30 mm or shorter. A second cervical length measurement was performed for 167 (75.6%) patients; no differences were identified in the odds of spontaneous preterm delivery when evaluated using the first, second, or a mean of both measurements, regardless of whether cervical length was analyzed as a continuous or dichotomous variable.

CONCLUSION

Among patients with singleton pregnancies, verification of short cervical length did not improve the identification of short cervical length.

Pessary or Progesterone to Prevent Preterm delivery in women with short cervical length: the Quadruple P randomised controlled trial

BACKGROUND

Preterm birth is in quantity and in severity the most important topic in obstetric care in the developed world. Progestogens and cervical pessaries have been studied as potential preventive treatments with conflicting results. So far, no study has compared both treatments.

METHODS/DESIGN

The Quadruple P study aims to compare the efficacy of vaginal progesterone and cervical pessary in the prevention of adverse perinatal outcome associated with preterm birth in asymptomatic women with a short cervix, in singleton and multiple pregnancies separately. It is a nationwide open-label multicentre randomized clinical trial (RCT) with a superiority design and will be accompanied by an economic analysis. Pregnant women undergoing the routine anomaly scan will be offered cervical length measurement between 18 and 22 weeks in a singleton and at 16-22 weeks in a multiple pregnancy. Women with a short cervix, defined as less than, or equal to 35 mm in a singleton and less than 38 mm in a multiple pregnancy, will be invited to participate in the study. Eligible women will be randomly allocated to receive either progesterone or a cervical pessary. Following randomization, the silicone cervical pessary will be placed during vaginal examination or 200 mg progesterone capsules will be daily self-administered vaginally. Both interventions will be continued until 36 weeks gestation or until delivery, whichever comes first. Primary outcome will be composite adverse perinatal outcome of perinatal mortality and perinatal morbidity including bronchopulmonary dysplasia, intraventricular haemorrhage grade III and IV, periventricular leukomalacia higher than grade I, necrotizing enterocolitis higher than stage I, Retinopathy of prematurity (ROP) or culture proven sepsis. These outcomes will be measured up until 10 weeks after the expected due date. Secondary outcomes will be, among others, time to delivery, preterm birth rate before 28, 32, 34 and 37 weeks, admission to neonatal intensive care unit, maternal morbidity, maternal admission days for threatened preterm labour and costs.

DISCUSSION

This trial will provide evidence on whether vaginal progesterone or a cervical pessary is more effective in decreasing adverse perinatal outcome in both singletons and multiples.

TRIAL REGISTRATION

Trial registration number: NTR 4414 . Date of registration January 29th 2014.

Implementing universal cervical length screening in asymptomatic women with singleton pregnancies: challenges and opportunities

Cervical length (CL) screening has been successfully utilised to identify asymptomatic women, with a singleton pregnancy, at risk of preterm birth (PTB), thereby providing an opportunity to offer interventions that may reduce that risk. Cervical length screening with ultrasound is most effectively performed with a transvaginal approach. Universal cervical length screening, encompassing all singleton pregnancies rather than restricting screening to those considered at increased risk of PTB, is currently not widely used, despite a growing body of evidence in support of its utility for PTB prevention. There are a number of barriers that may prevent or restrict the implementation of a universal CL screening program. These include cost, availability of vaginal progesterone and other treatment options, reluctance of women to undergo transvaginal ultrasound and the perceptions and beliefs of medical practitioners. Given that mid-pregnancy CL measurement is a recognised predictor of spontaneous PTB, that most cases of PTB occur with no prior maternal history and that there are interventions available that may reduce the risk of PTB, we believe there is a clear role for routine CL screening to be adopted as a component of the fetal morphology ultrasound examination. As a strategy to reduce PTB rates, discussion and counselling about PTB prevention and CL screening should be adopted as a core element of prenatal care.

Impact of fetal gender on the risk of preterm birth, a national cohort study

INTRODUCTION

Fetal gender is associated with preterm birth; however, a proper subdivision by onset of labor and corresponding neonatal outcome by week of gestation is lacking.

MATERIAL AND METHODS

Data from the Netherlands Perinatal Registry (1999-2010) were used to calculate relative risk ratios for gender by week of gestation and gender-related risk on adverse neonatal outcomes using a moving average technique. White European women with an alive fetus at onset of labor were included. Adverse neonatal outcomes were defined as neonatal mortality and a composite of neonatal morbidity. Onset of labor was categorized as spontaneous onset with intact membranes, premature rupture of membranes, and induction or elective cesarean section.

RESULTS

The study population comprised 1 736 615 singleton deliveries (25(+0) -42(+6) weeks). Male fetuses were at increased risk of spontaneous preterm birth with intact membranes compared with a female fetus with a peak between 27 and 31 weeks [relative risk (RR) 1.5; 95% CI 1.4-1.6]. Male fetuses were also at increased risk of preterm premature rupture of membranes between 27 and 37 weeks (RR 1.2; 95% CI 1.16-1.23). No gender effect was seen for medically indicated preterm birth. No significant differences were seen for neonatal mortality. Males were at significantly increased risk of composite neonatal morbidity from 29 weeks onwards (RR 1.3; 95% CI 1.3-1.4).

CONCLUSIONS

Male fetal gender is a relevant risk factor for spontaneous preterm birth, both for intact membranes and for preterm premature rupture of membranes in white European women. In addition, male infants are at increased risk of neonatal morbidity.

Midpregnancy Cervical Length in Nulliparous Women and its Association with Postterm Delivery and Intrapartum Cesarean Delivery

OBJECTIVE

To evaluate the association between midpregnancy cervical length and postterm delivery and cesarean delivery during labor.

STUDY DESIGN

In a multicenter cohort study, cervical length was measured in low-risk singleton pregnancies between 16 and 22 weeks of gestation. From this cohort, we identified nulliparous women who delivered beyond 34 weeks and calculated cervical length quartiles. We performed logistic regression to compare the risk of postterm delivery and intrapartum cesarean delivery to cervical length quartiles, using the lowest quartile as a reference. We adjusted for induction of labor, maternal age, ethnicity, cephalic position, preexisting hypertension, and gestational age at delivery.

RESULTS

We studied 5,321 nulliparous women. Women with cervical length in the 3rd and 4th quartile were more likely to deliver at 42(+0) to 42(+6) weeks (adjusted odds ratio [aOR] 2.02, 95% confidence interval [CI] 1.07-3.79 and aOR 1.97, 95% CI 1.06-3.67, respectively). The frequency of intrapartum cesarean delivery increased with cervical length quartile from 9.4% in the 1st to 14.9% in the 4th quartile (p = 0.01). This increase was only present in intrapartum cesarean delivery because of failure to progress and not because of fetal distress.

CONCLUSION

The longer the cervix at midtrimester the higher the risk of both postterm delivery and intrapartum cesarean delivery.

Fetal Gender of the First Born and the Recurrent Risk of Spontaneous Preterm Birth

OBJECTIVE

To study, in women with a spontaneous preterm birth (sPTB) in the first pregnancy, the effect of fetal sex in that first pregnancy on the recurrent sPTB risk.

STUDY DESIGN

A nationwide retrospective cohort study (data from National Perinatal Registry) on all women with two sequential singleton pregnancies (1999-2009) with the first delivery ending in sPTB <37 weeks. We used logistic regression analysis to study the association between fetal gender in the first pregnancy and the risk of recurrent sPTB. We repeated the analysis for sPTB < 32 weeks.

RESULTS

The overall incidence of sPTB <37 weeks in the first pregnancy was 4.5% (15,351/343,853). Among those 15,351 women, the risk of recurrent sPTB <37 weeks was increased when the first fetus was female compared when that fetus was male (15.8 vs. 15.2%; adjusted odds ratio [aOR] 1.2; 95% confidence interval [CI] 1.05-1.3). A similar effect was seen for sPTB <32weeks (8.2 vs. 5.9%; aOR 4.5; 95% CI 1.5-13).

CONCLUSION

Women who suffer sPTB of a female fetus have an increased risk of recurrent sPTB compared with women who suffer sPTB of a male fetus. This information provides proof for the hypothesis that sPTB is due to an independent maternal and fetal factor.

The capacity of mid-pregnancy cervical length to predict preterm birth in low-risk women: a national cohort study

INTRODUCTION

We investigated the predictive capacity of mid-trimester cervical length (CL) measurement for spontaneous and iatrogenic preterm birth.

MATERIAL AND METHODS

We performed a prospective observational cohort study in nulliparous women and low-risk multiparous women with a singleton pregnancy between 16(+0) and 21(+6) weeks of gestation. We assessed the prognostic capacity of transvaginally measured mid-trimester CL for spontaneous and iatrogenic preterm birth (<37 weeks) using likelihood ratios (LR) and receiver-operating-characteristic analysis. We calculated numbers needed to screen to prevent one preterm birth assuming different treatment effects. Main outcome measures were preterm birth <32, <34 and <37 weeks.

RESULTS

We studied 11,943 women, of whom 666 (5.6%) delivered preterm: 464 (3.9%) spontaneous and 202 (1.7%) iatrogenic. Mean CL was 44.1 mm (SD 7.8 mm). In nulliparous women, the LRs for spontaneous preterm birth varied between 27 (95% CI 7.7-95) for a CL ≤ 20 mm, and 2.0 (95% CI 1.6-2.5) for a CL between 30 and 35 mm. For low-risk multiparous women, these LRs were 37 (95% CI 7.5-182) and 1.5 (95% CI 0.97-2.2), respectively. Using a cut-off for CL ≤ 30 mm, 28 (6.0%) of 464 women with spontaneous preterm birth were identified. The number needed to screen to prevent one case of preterm birth was 618 in nulliparous women and 1417 for low-risk multiparous women (40% treatment effect, cut-off 30 mm).

CONCLUSION

In women at low risk of preterm birth, CL predicts spontaneous preterm birth. However, its isolated use as a screening tool has limited value due to low sensitivity.

Maternal and neonatal consequences of treated and untreated asymptomatic bacteriuria in pregnancy: a prospective cohort study with an embedded randomised controlled trial

BACKGROUND

Existing approaches for the screening and treatment of asymptomatic bacteriuria in pregnancy are based on trials that were done more than 30 years ago. In this study, we reassessed the consequences of treated and untreated asymptomatic bacteriuria in pregnancy.

METHODS

In this multicentre prospective cohort study with an embedded randomised controlled trial, we screened women (aged ≥18 years) at eight hospitals and five ultrasound centres in the Netherlands with a singleton pregnancy between 16 and 22 weeks' gestation for asymptomatic bacteriuria. Screening was done with a single dipslide and two culture media. Dipslides were judged positive when the colony concentration was at least 1×10(5) colony-forming units (CFU) per mL of a single microorganism or when two different colony types were present but one had a concentration of at least 1×10(5) CFU per mL. Asymptomatic bacteriuria-positive women were eligible to participate in the randomised controlled trial comparing nitrofurantoin with placebo treatment. In this trial, participants were randomly assigned 1:1 to receive either nitrofurantoin 100 mg or identical placebo tablets, and were instructed to self-administer these tablets twice daily for 5 consecutive days. Randomisation was done by a web-based application with a computer-generated list with random block sizes of two, four, or six participants rendered by an independent data manager. 1 week after the end of treatment, they provided us with a follow-up dipslide. Women, treating physicians, and researchers all remained unaware of the bacteriuria status and treatment allocation. Women who refused to participate in the randomised controlled trial did not receive any antibiotics, but their outcomes were collected for analysis in the cohort study. We compared untreated and placebo-treated asymptomatic bacteriuria-positive women with asymptomatic bacteriuria-negative women and nitrofurantoin-treated asymptomatic bacteriuria-positive women. The primary endpoint was a composite of pyelonephritis with or without preterm birth at less than 34 weeks, analysed by intention to treat at 6 weeks post-partum. This trial is registered with the Dutch Trial Registry, number NTR3068.

FINDINGS

Between Oct 11, 2011, and June 10, 2013, we enrolled 5621 women into our screening cohort, of whom 5132 were eligible for screening. After exclusions for contaminated dipslides and patients lost to follow-up, in our final cohort of 4283 women, 248 were asymptomatic bacteriuria positive, of whom 40 were randomly assigned to nitrofurantoin and 45 to placebo for the randomised controlled trial, whereas the other 163 asymptomatic bacteriuria-positive women were followed without treatment. The proportion of women with pyelonephritis, preterm birth, or both did not differ between untreated or placebo-treated asymptomatic bacteriuria-positive women and asymptomatic bacteriuria-negative women (6 [2·9%] of 208 vs 77 [1·9%] of 4035; adjusted odds ratio [OR] 1·5, 95% CI 0·6-3·5) nor between asymptomatic bacteriuria-positive women treated with nitrofurantoin versus those who were untreated or received placebo (1 [2·5%] of 40 vs 6 [2·9%] of 208; risk difference -0·4, 95% CI -3·6 to 9·4). Untreated or placebo-treated asymptomatic bacteriuria-positive women developed pyelonephritis in five [2·4%] of 208 cases, compared with 24 [0·6%] of 4035 asymptomatic bacteriuria-negative women (adjusted OR 3·9, 95% CI 1·4-11·4).

INTERPRETATION

In women with an uncomplicated singleton pregnancy, asymptomatic bacteriuria is not associated with preterm birth. Asymptomatic bacteriuria showed a significant association with pyelonephritis, but the absolute risk of pyelonephritis in untreated asymptomatic bacteriuria is low. These findings question a routine screen-treat-policy for asymptomatic bacteriuria in pregnancy.

FUNDING

ZonMw (the Netherlands Organisation for Health Research and Development).

Preventing Preterm Birth with Progesterone in Women with a Short Cervical Length from a Low-Risk Population: A Multicenter Double-Blind Placebo-Controlled Randomized Trial

OBJECTIVE

The objective of this study was to evaluate the effectiveness of vaginal progesterone in reducing adverse neonatal outcome due to preterm birth (PTB) in low-risk pregnant women with a short cervical length (CL).

STUDY DESIGN

Women with a singleton pregnancy without a history of PTB underwent CL measurement at 18 to 22 weeks. Women with a CL ≤ 30 mm received vaginal progesterone or placebo. Primary outcome was adverse neonatal outcome, defined as a composite of respiratory distress syndrome, bronchopulmonary dysplasia, intracerebral hemorrhage > grade II, necrotizing enterocolitis > stage 1, proven sepsis, or death before discharge. Secondary outcomes included time to delivery, PTB before 32, 34, and 37 weeks of gestation. Analysis was by intention to treat.

RESULTS

Between 2009 and 2013, 20,234 women were screened. A CL of 30 mm or less was seen in 375 women (1.8%). In 151 women, a CL ≤ 30 mm was confirmed with a second measurement and 80 of these women agreed to participate in the trial. We randomly allocated 41 women to progesterone and 39 to placebo. Adverse neonatal outcomes occurred in two (5.0%) women in the progesterone and in four (11%) women in the control group (relative risk [RR], 0.47; 95% confidence interval [CI], 0.09-2.4). The use of progesterone resulted in a nonsignificant reduction of PTB < 32 weeks (2.0 vs. 8.0%; RR, 0.33; 95% CI, 0.04-3.0) and < 34 weeks (7.0 vs. 10%; RR, 0.73; 95% CI, 0.18-3.1) but not on PTB < 37 weeks (15 vs. 13%; RR, 1.2; 95% CI, 0.39-3.5).

CONCLUSION

In women with a short cervix, who are otherwise low risk, we could not show a significant benefit of progesterone in reducing adverse neonatal outcome and PTB.

Recurrence rate and outcome of postterm pregnancy, a national cohort study

OBJECTIVE

To assess the recurrence rate of postterm delivery (gestational age at or beyond 42+0 weeks or 294 days) and to describe maternal and perinatal outcomes after previous postterm delivery.

STUDY DESIGN

From the longitudinal linked Netherlands Perinatal Registry database, we selected all singleton primiparous women who delivered between 37+0 and 42+6 weeks with a subsequent singleton pregnancy from 1999 to 2007. We excluded congenital abnormalities. We compared the recurrence rate of postterm delivery and risk of antenatal fetal death in women with and without a postterm delivery in their first pregnancy. We compared perinatal outcome (composite of perinatal mortality, Apgar score <7 and birth injury) and adverse maternal outcome (composite of maternal death, abruptio placentae, PPH>1000ml and blood transfusions) between women with a recurrent and a de novo postterm second pregnancy.

RESULTS

Our study population consisted of 233,327 women of whom 17,874 (7.7%) delivered postterm in the first pregnancy. In the second pregnancy, 2678 (15%) women had a recurrent postterm delivery compared to 8698 (4%) women with a de novo postterm delivery (odds ratio (OR) 4.2 95% confidence interval (CI) 4.0-4.4). Subgroup analysis in recurrent and de novo postterm delivery showed no differences in composite perinatal and composite maternal outcome (OR 1.0; CI 0.7-1.5, p=0.90 and OR 1.1, CI 0.9-1.4, p=0.16), adjusted for fetal position and mode of delivery).

CONCLUSIONS

Women with a postterm delivery in the first pregnancy have a higher risk of recurrent postterm delivery. Our data suggest that there is no difference in the composite adverse perinatal outcome between recurrent and de novo postterm delivery.

Trial of labor after cesarean: attempted operative vaginal delivery versus emergency repeat cesarean, a prospective national cohort study

OBJECTIVE

To compare neonatal and maternal outcomes of attempted operative vaginal delivery with emergency repeat cesarean in trial of labor after cesarean.

STUDY DESIGN

Prospective 8-year cohort analysis using the Netherlands Perinatal Registry, including women with one prior cesarean giving birth through operative vaginal delivery or emergency repeat cesarean (n=12860). A multivariate analysis was performed. Odds ratios (OR) and adjusted odds ratios (aOR) were calculated.

RESULTS

Attempted operative vaginal delivery increases the risk on neonatal birth trauma (aOR 15.0 (5.94 to 38.0)) and postpartum hemorrhage (aOR 2.59 (2.17 to 3.09)), and lowers the risk of wet lung syndrome (aOR 0.53 (0.35 to 0.80)) and neonatal convulsions (aOR 0.47 (0.24 to 0.91)).

CONCLUSION

We found a highly increased risk of neonatal birth trauma and a moderately increased risk of postpartum hemorrhage but slightly lower risks of wet lung syndrome and neonatal convulsions after attempted operative vaginal delivery compared with emergency repeat cesarean.

Is cervical length associated with maternal characteristics?

OBJECTIVE

Women with a mid-trimester short cervical length (CL) are at increased risk for preterm delivery. Consequently, CL measurement is a potential screening tool to identify women at risk for preterm birth. Our objective was to assess possible associations between CL and maternal characteristics.

STUDY DESIGN

A nationwide screening study was performed in which CL was measured during the standard anomaly scan among low risk women with a singleton pregnancy. Data on maternal height, pre-pregnancy weight, ethnicity, parity and gestational age at the time of the CL measurement were collected from January 2010 to December 2012. Univariable and multivariable linear regression analyses were performed to assess the relationship between CL and maternal characteristics.

RESULTS

We included 5092 women. The mean CL was 44.3mm. No association was found between CL and maternal height or gestational age of the measurement. Maternal weight was associated with CL (p=0.007, adjusted R(2) 0.03). Separate analysis for BMI did not change these results. Ethnicity, known in 2702 out of 5092 women, was associated with CL (mean CL in Caucasian women 45.0mm, Asian 43.9mm, Mediterranean 43.1mm, and African 41.8mm, p=0.003), as well as parity (mean CL multiparous 45.3mm, nulliparous 43.5mm, p<0.0001).

CONCLUSION

Shorter mid-trimester cervical length is associated with higher maternal weight, younger maternal age, nulliparity and non-Caucasian ethnicity, but not with maternal height.

Optimal timing of delivery in small for gestational age fetuses near term: a national cohort study

OBJECTIVE

Our aim was to study the competing risks of antepartum versus intrapartum/neonatal death in small for gestational age (SGA) and non-SGA fetuses.

STUDY DESIGN

We performed a national cohort study using all singletons delivered between 36 and 42(6/7) weeks without hypertension, preeclampsia, diabetes, congenital anomalies, or noncephalic presentation from the Netherlands Perinatal Registry (1999-2007). The resultant cohort was divided in three groups based on birth weight by gestational age (SGA < P5 group, 61,021 deliveries; SGA P5-10 group, 58,902 deliveries; non-SGA group 1,168,523 deliveries). We compared the mortality risk of delivery with expectant management.

RESULTS

Delivery was associated with more mortality than expectant management for 1 week from 39 weeks onward in the non-SGA group (relative risk [RR], 1.26; 95% confidence interval [CI], 1.05-1.50). For the SGA < P5, expectant management for 1 more week was associated with more mortality from 38 weeks onward although this only reached statistical significance from 40 weeks onward (RR, 2.46; 95% CI, 1.80-3.36).

CONCLUSION

At 36 and 37 weeks, delivery is associated with a higher risk of mortality in SGA < P5 fetuses than expectant management. Delivery of SGA < P5 fetuses at 38 and 39 weeks is associated with the best perinatal outcome whereas for non-SGA fetuses this is at 39 to 40 weeks.

Recurrence of small-for-gestational-age pregnancy: analysis of first and subsequent singleton pregnancies in The Netherlands

OBJECTIVE

Small-for-gestational-age (SGA) neonates are at increased risk of adverse pregnancy outcome. Our objective was to study the recurrence rate of SGA in subsequent pregnancies.

STUDY DESIGN

A prospective national cohort study of all women with a structurally normal first and subsequent singleton pregnancy from 1999-2007. SGA was defined as birthweight <5th percentile for gestation. We compared the incidence and recurrence rate of SGA for women in total and with and without a hypertensive disorder (HTD) in their first pregnancy. Moreover, we assessed the association between gestational age at first delivery and SGA recurrence.

RESULTS

We studied 259,481 pregnant women, of whom 12,943 women (5.0%) had an SGA neonate in their first pregnancy. The risk of SGA in the second pregnancy was higher in women with a previous SGA neonate than for women without a previous SGA neonate (23% vs 3.4%; adjusted odds ratio, 8.1; 95% confidence interval, 7.8-8.5) and present in both women with and without an HTD in pregnancy. In women without an HTD, the increased recurrence risk was independent of the gestational age at delivery in the index pregnancy; whereas in women with an HTD, this recurrence risk was increased only when the woman with the index delivery delivered at >32 weeks' gestation.

CONCLUSION

Women with SGA in their first pregnancy have a strongly increased risk of SGA in the subsequent pregnancy and first pregnancy SGA delivers a significant contribution to the total number of second pregnancy SGA cases.

Is short first-trimester crown-rump length associated with spontaneous preterm birth?

OBJECTIVE

To assess the association between first-trimester crown-rump length (CRL) and the risk of spontaneous preterm birth before 32 weeks' gestation.

METHODS

We performed a matched case-control study of 129 women with spontaneous preterm birth at < 32 weeks' gestation (cases) and 129 women with term deliveries (controls) using data stored in the ultrasound and obstetric databases of our tertiary referral center. Cases and controls were individually matched based on maternal age, parity, history of preterm birth and medical indication for antenatal care. Fetal CRL measured between 8 + 0 and 13 + 6 weeks was expressed as multiples of the median (MoM) expected CRL, based on last menstrual period. We investigated the association between CRL-MoM and spontaneous preterm birth using logistic regression analysis.

RESULTS

CRL-MoM was not associated with spontaneous preterm birth: odds ratio (OR) 1.10 (95% CI, 0.89-1.36) per 0.10 MoM increase in CRL. Timing of measurement did not influence the model (P = 0.59). This was confirmed when restricting the analysis to the 93 pairs with CRL measurements made between 10 + 0 and 13 + 6 weeks: OR for preterm birth 1.07 (95% CI, 0.83-1.37) per 0.10 MoM increase in CRL.

CONCLUSION

A short CRL in the first trimester is not associated with spontaneous preterm birth before 32 weeks' gestation, thus short CRL cannot be used to identify women at increased risk of preterm birth.

Costs and effects of screening and treating low risk women with a singleton pregnancy for asymptomatic bacteriuria, the ASB study

Background

The prevalence of asymptomatic bacteriuria (ASB) in pregnancy is 2-10% and is associated with both maternal and neonatal adverse outcomes as pyelonephritis and preterm delivery. Antibiotic treatment is reported to decrease these adverse outcomes although the existing evidence is of poor quality.

Methods/Design

We plan a combined screen and treat study in women with a singleton pregnancy. We will screen women between 16 and 22 weeks of gestation for ASB using the urine dipslide technique. The dipslide is considered positive when colony concentration ≥10⁵ colony forming units (CFU)/mL of a single microorganism or two different colonies but one ≥10⁵ CFU/mL is found, or when Group B Streptococcus bacteriuria is found in any colony concentration. Women with a positive dipslide will be randomly allocated to receive nitrofurantoin or placebo 100 mg twice a day for 5 consecutive days (double blind). Primary outcomes of this trial are maternal pyelonephritis and/or preterm delivery before 34 weeks. Secondary outcomes are neonatal and maternal morbidity, neonatal weight, time to delivery, preterm delivery rate before 32 and 37 weeks, days of admission in neonatal intensive care unit, maternal admission days and costs.

Discussion

This trial will provide evidence for the benefit and cost-effectiveness of dipslide screening for ASB among low risk women at 16–22 weeks of pregnancy and subsequent nitrofurantoin treatment.

Trial registration

Dutch trial registry: NTR-3068