Does induction of labour increase the risk of caesarean section? A systematic review and meta-analysis of trials in women with intact membranes

Establishing a risk score for prediction of intrapartum cesarean delivery among older women: A retrospective cohort study

OBJECTIVE

To determine risk factors and to develop a risk prediction score for intrapartum cesarean delivery (CD) in women over 40 years old.

STUDY DESIGN

A retrospective cohort study, in a single university-affiliated tertiary medical center. All women aged 40 years or more who planned a trial of labor between 2012 and 2022. Women who opted for an elective CD and those with non-viable fetuses were excluded. Maternal and neonatal characteristics of women who delivered vaginally were compared to those who underwent an intrapartum CD. Risk factors were examined using univariate and multivariate analysis. A score was developed to predict the need for intrapartum CD. We assessed a receiver operating characteristic curve to evaluate the performance of our model.

MAIN OUTCOME MEASURE

An unplanned intrapartum cesarean section.

RESULTS

During the study period, 122,583 women delivered at our center, of whom 6122 (4.9 %) aged 40 years or more attempted a trial of labor. Of them, 428 (7 %) underwent intrapartum CD. Several independent risk factors were identified, including nulliparity, regional anesthesia, induction of labor, use of antibiotics during labor, multiple gestation, previous cesarean delivery, and the presence of gestational diabetes or preeclampsia. A risk score model, employing a cut-off of 7, demonstrated successful prediction of intrapartum CD, with an area under the curve of 0.86.

CONCLUSION

The score model for intrapartum CD can be used by caregivers to offer a more informed consultation to women aged 40 years or more deciding on the mode of delivery.

Induction of labor after one previous cesarean: Predictors of vaginal birth

Objective

To identify independent predictors for vaginal delivery after induction of labor after one cesarean (IOLAC).

Study design

In this retrospective cohort study, the electronic medical record of 19064 women who delivered from January 2018-September 2022 in a university hospital in Malaysia were individually searched to identify cases of IOLAC. Preselected data points on characteristics and the outcome of mode of delivery were retrieved. Bivariate analysis was performed to identify predictor characteristics for the dichotomous outcomes of vaginal delivery vs unplanned cesarean delivery. Variables with crude p < 0.05 were incorporated into a multivariable binary logistic regression analysis to identify independent predictors of vaginal delivery after IOLAC.

Results

819 IOLAC cases were identified. There were 465/819 (56.5 %) unplanned cesareans deliveries. Of the 14 selected characteristics, eight had p < 0.05 on bivariate analysis. After adjustment, six characteristics, body mass index, height, ethnicity, parity, previous cesarean indication and Bishop score were independently predictive of vaginal birth but not maternal age or method of labor induction. Birthweight, labor induction indication, gestational age, haemoglobin level, diabetes and hypertension in pregnancy were not significant at the level of bivariate analysis.

Conclusion

Obesity, short stature, no prior vaginal delivery, previous cesarean indicated by failure to progress, unfavorable Bishop score and ethnicity were independent predictors for unplanned cesarean after IOLAC. These predictors should help guide women and their care providers in their shared decision-making about IOLAC.

Perinatal and maternal outcomes according to timing of induction of labour: A systematic review and meta-analysis

The risk of adverse perinatal and maternal outcomes increases with gestational age, and although induction of labour may reduce these risks, the optimal timing of induction remains unknown. We carried out a systematic review and meta-analysis, to determine the gestational age at which induction should be offered. We searched Cochrane Central Register of Controlled Trials, Medline, and Embase databases from inception to July 2022, to identify randomised trials comparing induction of labour at or beyond 37' weeks gestation with expectant management or delayed induction, and according to the gestational age at planned induction. We undertook random effects meta-analysis and pooled estimates as odds ratios with 95% confidence intervals. We assessed risk of bias of studies using the Cochrane Risk of Bias tool 2.0. We included 44 trials (23,960 women and 22,191 offspring) from 1,839 citations in our meta-analysis. The odds of perinatal death (odds ratio 0.42, 95% confidence interval 0.22 to 0.81; 26 studies, 20,154 offspring), stillbirth (0.40, 0.16 to 0.98; 25 studies, 19,412 offspring), admission to neonatal intensive care unit (0.86, 0.78 to 0.96; 23 studies, 18,846 offspring), and caesarean section (0.90, 0.83 to 0.98; 40 studies, 23,616 women) were reduced in the induction of labour group compared to expectant management or delayed induction. The odds of admission to neonatal intensive care unit (0.82, 0.70 to 0.96; 6 studies, 9,316 offspring) were lower with induction of labour at 41 weeks compared to induction at or after 42 weeks' gestation, and the odds of caesarean section were reduced with labour induction at 39 weeks' compared to induction at or after 40 weeks' (0.83, 0.74 to 0.93; 8 studies, 7,677 women). There were no significant differences in pregnancy outcomes by method of induction of labour. Induction of labour compared to expectant management or delayed induction reduces the risk of adverse pregnancy outcomes, and the optimal timing may depend on the specific outcome of interest.

Induction or spontaneous labor for pregnant patients on anticoagulants?

OBJECTIVE

There are two approaches to peripartum management for pregnant patients undergoing anticoagulation treatments: spontaneous labor or scheduling an induction. A long interval without anticoagulation is a thrombosis risk factor, while a short interval leads to risks of delivery without epidural analgesia or post partum hemorrhage. Our objective was to evaluate the impact of planned induction versus spontaneous labor on obtaining neuraxial analgesia.

MATERIALS AND METHODS

A retrospective single-center study was conducted from 2012 to 2020 including all patients on preventive or curative low molecular-weight heparin at the time of delivery, excluding planned cesarean sections. The rates of neuraxial analgesia were compared between two groups: spontaneous labor and induction, as well as the intervals without anticoagulants.

RESULTS

127 patients were included. In the spontaneous labor group, 78% (44/56) received neuraxial analgesia versus 88% (37/42) in the induction group (p = 0.29). For curative dose treatment, the rate of neuraxial analgesia was 45,5% in the spontaneous group versus 78,6% (p = 0.12). The median time without anticoagulation was 34 h [26-46] in the spontaneous labor group and 43 h [34-54] in the induction group (p = 0.01), without an increased incidence of thrombosis. The rate of postpartum hemorrhage did not differ between the two groups.

CONCLUSION

Planned induction tended to increase the rate of neuraxial analgesia, without reaching significance, and most women in spontaneous labor accessed analgesia. Peripartum management should be a shared decision with the patient considering the obstetrical and thrombosis risk context for each patient.

Elective induction of labour at full-term gestations and childhood school outcomes

AIM

To explore the association between induction of labour at full-term gestations in low-risk nulliparous women and childhood school outcomes.

METHODS

A retrospective whole-of-population cohort study linking perinatal data to educational test scores at grades 3, 5 and 7 in Victoria, Australia. Low-risk nulliparous women with singleton pregnancies induced at 39 and 40 weeks without a medical indication were compared to those expectantly managed from that week of gestation. Multivariable logistic regressions were used as well as generalised estimating equations on longitudinal data.

RESULTS

At 39 weeks, there were 3687 and 103 164 infants in the induction and expectant arms, respectively. At 40 weeks' gestation, there were 7914 and 70 280 infants, respectively. Infants born to nulliparous women induced at 39 weeks' gestation had significantly poorer educational outcomes at grade 3 (adjusted odds ratio (aOR) = 1.39, 95% confidence interval (CI): 1.13-1.70) but not grades 5 (aOR = 1.05, 95% CI: 0.84-1.33) and 7 (aOR = 1.07, 95% CI: 0.81-1.40) compared to those expectantly managed. Infants born to nulliparous women induced at 40 weeks had comparable educational outcomes at grade 3 (aOR = 1.06, 95% CI: 0.90-1.25) but poorer educational outcomes at grades 5 (aOR = 1.23, 95% CI: 1.05-1.43) and 7 (aOR = 1.23, 95% CI: 1.03-1.47) compared to those expectantly managed.

CONCLUSIONS

There were inconsistent associations between elective induction of labour at full-term gestations in low-risk nulliparous women and impaired childhood school outcomes.

Comparison of Vaginal Birth Rate between Induction of Labour and Expectant Management at 40 Weeks in Women with a Previous Caesarean Section: A Pilot Randomized Controlled Trial

Background

The optimum time of labour induction among women with a previous caesarean without any pregnancy complication and eligible and willing for vaginal delivery is not specified. This study compares the vaginal birth rates between induction at 40 weeks and expectant management till 41 weeks.

Method

We conducted this parallel design nonblinded, randomized controlled trial in a tertiary care teaching institution in South India on women with a previous lower segment caesarean section eligible for a trial of labour with singleton foetus without any pregnancy complication at recruitment. We screened 1886 women. Sixty women underwent block (of 6 each) randomization into two groups of thirty each at 40 weeks. We induced the women in the intervention group at 40 weeks with oxytocin or a single 24-hour application of a Foley catheter followed by oxytocin infusion and amniotomy. The expectant group underwent maternal and foetal surveillance and induction at 41 weeks with the same protocol if not delivered by then. We compared the primary outcome of the proportion of vaginal birth rate with a chi-square test.

Result

Data from all sixty women were analyzed. Twenty (66.67%) in the induction compared to ten (33.33%) in the expectant group delivered vaginally. This difference was significant (RR 2.0, 95% CI: 1.13-3.52; P = 0.016). One woman in the expectant group had scar dehiscence.

Conclusion

Among women with a previous caesarean scar, labour induction at 40 weeks has a significantly higher vaginal birth rate than those managed expectantly till 41 weeks. More extensive trials are feasible and recommended. Trial Registry. The trial was prospectively registered with the clinical trial registry of India. This trial is registered with CTRI/2018/09/015719 (date of registration 14th September 2018).

Does induction of labor at 41 weeks (early, mid or late) improve birth outcomes in low-risk pregnancy? A nationwide propensity score-matched study

INTRODUCTION

This study aimed to assess whether induction of labor at 41 weeks of gestation improved perinatal outcomes in a low-risk pregnancy compared with expectant management.

MATERIAL AND METHODS

Registry-based national cohort study in The Netherlands. The study population comprised 239 971 low-risk singleton pregnancies from 2010 to 2019, with birth occurring from 41+0 to 42+0 weeks. We used propensity score matching to compare induction of labor in three 2-day groups to expectant management, and further conducted separate analyses by parity. The main outcome measures were stillbirth, perinatal mortality, 5-min Apgar <4 and <7, neonatal intensive care unit (NICU) admissions ≥24 h, and emergency cesarean section rate.

RESULTS

Compared with expectant management, induction of labor at 41+0 to 41+1 weeks resulted in reduced stillbirths (adjusted odds ratio [aOR] 0.15, 95% confidence interval [CI] 0.05-0.51) in both nulliparous and multiparous women. Induction of labor increased 5-min Apgar score <7 (aOR 1.30, 95% CI 1.09-1.55) and NICU admissions ≥24 h (aOR 2.12, 95% CI 1.53-2.92), particularly in nulliparous women, and increased the cesarean section rate (aOR 1.42, 95% CI 1.34-1.51). At 41+2-41+3 weeks, induction of labor reduced perinatal mortality (aOR 0.13, 95% CI 0.04-0.43) in both nulliparous and multiparous women. The rate of 5-min Apgar score <7 was increased (aOR 1.26, 95% CI 1.06-1.50), reaching significance in multiparous women. The cesarean section rate increased (aOR 1.57, 95% CI 1.48-1.67) in both nulliparous and multiparous women. Induction of labor at 41+4 to 41+5 weeks reduced stillbirths (aOR 0.30, 95% CI 0.10-0.93). Induction of labor increased rates of 5-min Apgar score <4 (aOR 1.61, 95% CI 1.01-2.56) and NICU admissions ≥24 h (aOR 1.52, 95% CI 1.08-2.13) in nulliparous women. Cesarean section rate was increased (aOR 1.47, 95% CI 1.38-1.57) in nulliparous and multiparous women.

CONCLUSIONS

At 41+2 to 41+3 weeks, induction of labor reduced perinatal mortality, and in all 2-day groups at 41 weeks, it reduced stillbirths, compared with expectant management. Low 5-min Apgar score (<7 and <4) and NICU admissions ≥24 h occurred more often with induction of labor, especially in nulliparous women. Induction of labor in all 2-day groups coincided with elevated cesarean section rates in nulliparous and multiparous women. These findings pertaining to the choice of induction of labor versus expectant management should be discussed when counseling women at 41 weeks of gestation.

Induction of labour at or near term for suspected fetal macrosomia

BACKGROUND

Women with a suspected large-for-dates fetus or a fetus with suspected macrosomia (birthweight greater than 4000 g) are at risk of operative birth or caesarean section. The baby is also at increased risk of shoulder dystocia and trauma, in particular fractures and brachial plexus injury. Induction of labour may reduce these risks by decreasing the birthweight, but may also lead to longer labours and an increased risk of caesarean section.

OBJECTIVES

To assess the effects of a policy of labour induction at or shortly before term (37 to 40 weeks) for suspected fetal macrosomia on the way of giving birth and maternal or perinatal morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2016), contacted trial authors and searched reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials of induction of labour for suspected fetal macrosomia.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We contacted study authors for additional information. For key outcomes the quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included four trials, involving 1190 women. It was not possible to blind women and staff to the intervention, but for other 'Risk of bias' domains these studies were assessed as being at low or unclear risk of bias. Compared to expectant management, there was no clear effect of induction of labour for suspected macrosomia on the risk of caesarean section (risk ratio (RR) 0.91, 95% confidence interval (CI) 0.76 to 1.09; 1190 women; four trials, moderate-quality evidence) or instrumental delivery (RR 0.86, 95% CI 0.65 to 1.13; 1190 women; four trials, low-quality evidence). Shoulder dystocia (RR 0.60, 95% CI 0.37 to 0.98; 1190 women; four trials, moderate-quality evidence), and fracture (any) (RR 0.20, 95% CI 0.05 to 0.79; 1190 women; four studies, high-quality evidence) were reduced in the induction of labour group. There were no clear differences between groups for brachial plexus injury (two events were reported in the control group in one trial, low-quality evidence). There was no strong evidence of any difference between groups for measures of neonatal asphyxia; low five-minute infant Apgar scores (less than seven) or low arterial cord blood pH (RR 1.51, 95% CI 0.25 to 9.02; 858 infants; two trials, low-quality evidence; and, RR 1.01, 95% CI 0.46 to 2.22; 818 infants; one trial, moderate-quality evidence, respectively). Mean birthweight was lower in the induction group, but there was considerable heterogeneity between studies for this outcome (mean difference (MD) -178.03 g, 95% CI -315.26 to -40.81; 1190 infants; four studies; I2 = 89%).  For outcomes assessed using GRADE, we based our downgrading decisions on high risk of bias from lack of blinding and imprecision of effect estimates.

AUTHORS' CONCLUSIONS

Induction of labour for suspected fetal macrosomia has not been shown to alter the risk of brachial plexus injury, but the power of the included studies to show a difference for such a rare event is limited. Also antenatal estimates of fetal weight are often inaccurate so many women may be worried unnecessarily, and many inductions may not be needed. Nevertheless, induction of labour for suspected fetal macrosomia results in a lower mean birthweight, and fewer birth fractures and shoulder dystocia. The observation of increased use of phototherapy in the largest trial, should also be kept in mind. Findings from trials included in the review suggest that to prevent one fracture it would be necessary to induce labour in 60 women. Since induction of labour does not appear to alter the rate of caesarean delivery or instrumental delivery, it is likely to be popular with many women. In settings where obstetricians can be reasonably confident about their scan assessment of fetal weight, the advantages and disadvantages of induction at or near term for fetuses suspected of being macrosomic should be discussed with parents. Although some parents and doctors may feel the evidence already justifies induction, others may justifiably disagree. Further trials of induction shortly before term for suspected fetal macrosomia are needed. Such trials should concentrate on refining the optimum gestation of induction, and improving the accuracy of the diagnosis of macrosomia.

Effectiveness and safety of membrane sweeping in the prevention of post-term pregnancy: a randomised controlled trial

There is a rising concern with increasing rates of pharmacologically induced labour and its complications. Membrane sweeping is a simple and less invasive means of initiating spontaneous labour onset. We compared the safety and efficacy of membrane sweeping. A total of 186 women (62 in each arm) were recruited at the antenatal clinic at 39 weeks. The intervention groups had membrane sweeping once and twice weekly respectively while the control arm had no membrane sweeping. They were all monitored and followed up till delivery. The trial was registered with the South Africa registry www.pactr.org (PACTR202112841108933) The incidence of prolonged pregnancy was 32.3%, 19.4% and 11.7% among the control, once-weekly, and twice-weekly groups respectively. The sweeping to the delivery interval was significantly shorter for the twice-weekly group (7.4 days) compared to once weekly (8.8 days) and the control group (10.6 days). There were significantly higher odds of spontaneous labour onset in the twice-weekly group (HR 1.53, p = .029) compared to the control group (HR 0.65, p = .033) and the once-weekly group using once weekly as reference. Membrane sweeping is a safe and effective means of preventing prolonged pregnancy. Twice-weekly sweeping of foetal membranes is more effective than once-weekly or no sweeping without added adverse feto-maternal outcomes.IMPACT STATEMENTWhat is already known about the subject? There is no evidence supporting any increase in maternal or foetal morbidity suggesting that membrane sweeping is a safe procedure to offer to all low-risk pregnant women so as to initiate spontaneous labour onset.What do the results of the study add? Membrane sweeping twice weekly after 39weeks for low-risk pregnant women is more effective than once weekly or no sweep with no added adverse maternal or perinatal risks.What are the implications of these findings for clinical practice and or further research? Twice-weekly membrane sweeping is encouraged in selected patients to reduce the risks associated with post-term pregnancy.

Synthetic osmotic dilators (Dilapan-S) or dinoprostone vaginal inserts (Propess) for inpatient induction of labour: A UK cost-consequence model

OBJECTIVE

To estimate the costs of synthetic osmotic dilators (Dilapan-S) compared to dinoprostone vaginal inserts (Propess) for inpatient induction of labour (IOL).

STUDY DESIGN

A population-level, Markov model-based cost-consequence analysis was developed to compare the impact of using Dilapan-S versus Propess. The time horizon was modelled from admission to birth. The target population was women requiring inpatient IOL from 37 weeks with an unfavourable cervix in the UK. Mean population characteristics reflected those of the SOLVE (NCT03001661) trial. No patient data were included in this analysis. The care pathways and staff workload were modelled using data from the SOLVE trial and clinical experience. Cost and clinical inputs were sourced from the SOLVE trial and peer-reviewed literature. Costs were inflated to 2020 British pounds (GBP, £). Outcomes were reported as an average per woman for total costs and required staff time (minutes) from admission for IOL until birth. The model robustness was assessed using a probabilistic, multivariate sensitivity analysis of 2,000 simulations with results presented as the median (interquartile range, IQR).

RESULTS

Dilapan-S was cost neutral compared to Propess. Midwife and obstetrician times were decreased by 146 min (-11%) and 11 min (-54%), respectively. Sensitivity analysis showed that in 78% of simulations, use of Dilapan-S reduced midwife time with a median of -160 min (IQR -277 to -24 min). Costs were reduced in 54% of simulations (median -£33, IQR -£319 to £282).

CONCLUSIONS

The model indicates that adoption of Dilapan-S is likely to be cost-neutral and reduce staff workload in comparison to Propess. Results require support from real-world data and further exploration of Dilapan-S is to be encouraged.

Breaking the myth: the association between the increasing incidence of labour induction and the rate of caesarean delivery in Finland - a nationwide Medical Birth Register study

OBJECTIVES

To determine the association between the rate of labour induction and caesarean delivery.

DESIGN

Medical Birth Register-based study. We used data from the nationwide Medical Birth Register collecting data on delivery outcomes on all births from 22+0 weeks and/or birth weight of at least 500 g.

SETTING

Finland.

PARTICIPANTS

663 024 live births in Finland from 2008 to 2019.

MAIN OUTCOME MEASURES

The rates of labour induction and caesarean delivery.

RESULTS

The rate of labour induction increased from 17.8% to 30.3%; p<0.001, during the study. The total caesarean delivery rate was 16.5% (n=109 178). An increase of approximately 0.5% in the caesarean delivery rate occurred during the study period. The rate of caesarean delivery following labour induction slightly decreased (15.41% vs 15.35%; p<0.001). In multivariate logistic regression analysis, induction of labour was associated with a reduced risk for caesarean delivery (OR 0.72, 95% CI 0.71 to 0.74). The frequency of advanced maternal age (18.0% vs 23.5%; p<0.001), obesity (11.4% vs 15.1%; p<0.001) and gestational diabetes (9.8% vs 23.3%; p<0.001) increased during the study.

CONCLUSIONS

The 70% increase in the rate of labour induction in Finland has not led to a significant increase in the rate of caesarean delivery, which has remained one of the lowest in the world. Pregnant women in Finland are more frequently obese, older and diagnosed with gestational diabetes, which may partly explain the increase in the rate of labour induction.

Efficacy and Safety Analysis of Phloroglucinol in Combination with Oxytocin for the Induction of Labor in Women with Term Premature Rupture of Membranes (PROM)

Objective. The purpose of this study was to investigate the efficacy and safety of phloroglucinol in combination with oxytocin in the induction of labor in women who had experienced term premature rupture of membranes (PROM). Methods. Data from 100 women who experienced PROM between December 2020 and December 2021 were retrospectively evaluated in this study. The puerperae were categorized into observation and control groups based on their uterine contraction regimens. The observation group consisted of 53 participants that had been treated with phloroglucinol in combination with oxytocin, and the control group consisted of 47 participants that had been treated with oxytocin alone. It was observed and compared in terms of the Bishop score before and after the administration of the puerpera to see which group had the best index. A study was performed after the drug was administered to examine its effects on the duration of labor (including the first, second, and third stages of labor), the mode of delivery (including natural vaginal delivery and cesarean section), the incidence of adverse pregnancy outcomes (fetal distress and neonatal asphyxia), successful labor induction, and complication rates. Results. Patients in the observation group had a significantly higher Bishop score after administration than those in the control group ( $P<0.05$ ), although there was no difference between the two groups before administration. In comparison to the control group, the observation group had a significantly higher efficacy rate for drug administration ( $P<0.05$ ), as well as a significantly lower occurrence of the first stage of labor ( $P<0.05$ ), a higher rate of vaginal natural delivery and successful induction of labor ( $P<0.05$ ), and a significantly lower incidence of adverse pregnancy outcomes and complications ( $P<0.05$ ). Conclusion. In conclusion, the use of phloroglucinol in combination with intravenous oxytocin in the process of promoting cervical ripening and induction of labor for women with PROM who are at term was investigated. This study could help women speed up cervical dilation, improve the cervical Bishop scores, shorten the total labour process, improve the effective rate of vaginal delivery, and be very safe, making it a good candidate for clinical promotion and application.

Analysis of cesarean section rates and its indications using robson's classification at a tertiary care hospital, Manipur

Context

The World Health Organization proposed the Robson's classification system as a global standard for assessing and comparing cesarean section (CS) rates within health-care facilities over time and between facilities.

Aims

This study aims to assess the frequency and indications of CS and to identify the groups within the obstetric population contributing to CS using Robson's classification.

Settings and Design

A retrospective chart review was conducted in a Tertiary Care Teaching Hospital in Imphal, Manipur.

Methods

All women who delivered between January and December 2019 were classified using the Robson's Ten Group Classification System. The overall CS rate and the CS rate in each Robson's group were calculated. The indications for CS were also recorded.

Statistical Analysis Used

Descriptive statistics, such as frequency, percentage, mean, and standard deviation, was used.

Results

A total of 10,282 births were reported. The overall CS rate was 35.2%. Group 3 (multiparous women without previous CS in spontaneous labor) (27.6%) and Group 1 (nulliparous women in spontaneous labor) (23.7%) contributed to most of the obstetric populations. The majority of CS belonged to the women in Group 5 (multiparous women with previous lower segment CS) (11%), followed by Group 2 (nulliparous women with labor induced or prelabor CS) (8.6%) and Group 4 (multiparous women without previous CS were induced or taken for prelabor CS) (5.5%).

Conclusions

The study revealed that Groups 5, 2, and 4 contributed to the high CS rate. Efforts to reduce the overall CS rate should be directed at increasing vaginal births after CS, performing effective pelvic examinations, and encouraging obstetricians to perform versions when indicated.

Attributable factors for the rising cesarean delivery rate over three decades: an observational cohort study

BACKGROUND

Cesarean delivery rates continue to rise globally the reasons for which are incompletely understood.

OBJECTIVES

We aimed to characterize attributable factors for increasing cesarean delivery rates over a 30-year period within our health network.

STUDY DESIGN

This was a planned observational cohort study across two hospitals (a large tertiary referral hospital and a metropolitan hospital) in Sydney, Australia using data from a previously published study. Two time periods were compared: 1989-1999 and 2009-2016, between which the cesarean delivery rate increased from 19% to 30%. Participants were all women who had a cesarean delivery after 24 weeks gestational age. Data were analyzed using multiple imputation and robust Poisson regression to calculate differences in the adjusted and unadjusted relative risk of cesarean delivery and estimate the changes in the cesarean delivery rate attributable to maternal and clinical factors. The primary outcome was cesarean delivery.

RESULTS

After 576 exclusions, 102 589 births were included in the analysis. Fifty-six percent of the increase in the rate of cesarean delivery was attributed to changes in the distribution of maternal age, body mass index, parity and history of previous cesarean delivery. An additional 10% of the increase was attributed to changes in the obstetric management of the following high-risk pregnancies: multiple gestation, malpresentation (mainly breech) and preterm singleton birth. When pre-labor cesarean deliveries for maternal choice, suspected fetal compromise, previous pregnancy issues and suspected large fetus were excluded, 78% of the increase was attributed to either maternal factors or changes in the obstetric management of these high-risk pregnancies.

CONCLUSIONS

Most of the steep rise in the cesarean delivery rate from 19% to 30% was attributed to changes in maternal demographic and clinical factors. This observation is relevant to developing preventative strategies which account for nulliparity, age, body mass index, and the management of high-risk pregnancies.

TWEETABLE ABSTRACT

More than half of the increase in the rate of cesarean delivery is attributable to changes in maternal age, BMI, parity and history of cesarean delivery.

Induction of labour at 41 weeks of gestation versus expectant management and induction of labour at 42 weeks of gestation: a cost-effectiveness analysis

OBJECTIVE

To assess the cost-effectiveness of induction of labour (IOL) at 41 weeks of gestation compared with expectant management until 42 weeks of gestation.

DESIGN

A cost-effectiveness analysis alongside the Swedish Post-term Induction Study (SWEPIS), a multicentre, randomised controlled superiority trial.

SETTING

Fourteen Swedish hospitals during 2016-2018.

POPULATION

Women with an uncomplicated singleton pregnancy with a fetus in cephalic position were randomised at 41 weeks of gestation to IOL or to expectant management and induction at 42 weeks of gestation.

METHODS

Health benefits were measured in life years and quality-adjusted life years (QALYs) for mother and child. Total cost per birth was calculated, including healthcare costs from randomisation to discharge after delivery, for mother and child. Incremental cost-effectiveness ratios (ICERs) were calculated by dividing the difference in mean cost between the trial arms by the difference in life years and QALYs, respectively. Sampling uncertainty was evaluated using non-parametric bootstrapping.

MAIN OUTCOME MEASURES

The cost per gained life year and per gained QALY.

RESULTS

The differences in life years and QALYs gained were driven by the difference in perinatal mortality alone. The absolute risk reduction in mortality was 0.004 (from 6/1373 to 0/1373). Based on Swedish life tables, this gives a mean gain in discounted life years and QALYs of 0.14 and 0.12 per birth, respectively. The mean cost per birth was €4108 in the IOL group (n = 1373) and €4037 in the expectant management group (n = 1373), with a mean difference of €71 (95% CI -€232 to €379). The ICER for IOL compared with expectant management was €545 per life year gained and €623 per QALY gained. Confidence intervals were relatively wide and included the possibility that IOL had both lower costs and better health outcomes.

CONCLUSIONS

Induction of labour at 41 weeks of gestation results in a better health outcome and no significant difference in costs. IOL is cost-effective compared with expectant management until 42 weeks of gestation using standard threshold values for acceptable cost per life year/QALY.

TWEETABLE ABSTRACT

Induction of labour at 41 weeks of gestation is cost-effective compared with expectant management until 42 weeks of gestation.

Induction of Labour. Guideline of the DGGG, OEGGG and SGGG (S2k, AWMF Registry No. 015-088, December 2020)

Aim The aim of this official guideline published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG) in cooperation with the Austrian Society of Gynaecology and Obstetrics (OEGGG) and the Swiss Society of Gynaecology and Obstetrics (SGGG) is to provide a consensus-based overview of the indications, methods and general management of induction of labour by evaluating the relevant literature. Methods This S2k guideline was developed using a structured consensus process which included representative members from various professions; the guideline was commissioned by the guidelines commission of the DGGG, OEGGG and SGGG. Recommendations The guideline provides recommendations on the indications, management, methods, monitoring and special situations occurring in the context of inducing labour.

Reducing the cesarean delivery rate

BACKGROUND

The cesarean delivery rate has been rising in recent years, having associated maternal morbidities. Elective induction of labor has also been seen to rise during this same time period.

OBJECTIVE

This current study investigated the difference in the cesarean delivery rate between induction of labor and spontaneous labor among nulliparous, term, singleton, and vertex-presenting women.

STUDY DESIGN

A retrospective cohort in a single institution over a seven-year period was used for this analysis, observing the difference in cesarean delivery rate at different term gestational ages and neonatal morbidity using the 5-minute Apgar score < 5.

RESULTS

A statistically significant difference was found in cesarean delivery rate between those women whose labor was induced and those whose labor began spontaneously, at each term gestational age of labor initiation (P < 0.001). The proportion of indications for induction was described (i.e. elective vs. medically-indicated), and no difference was found for neonatal morbidity between the groups analyzed, using the 5-minute Apgar score as the perinatal outcome measure.

CONCLUSION

A comparison was made between spontaneous and induced labor regarding the resultant cesarean delivery rate, and a significant difference was found favoring spontaneous labor. This should be considered when electing to deliver using an induction methodology for nulliparous women, especially when there are no medical indications for it.

Changes in the Frequency of Cesarean Delivery in Nulliparous Women in Labor in a Canadian Population, 1992-2018

OBJECTIVE

To examine the relative contribution of changes in patient demographics and physician management to changes in the cesarean delivery rate in labor among nulliparous women.

METHODS

We conducted a retrospective cohort study of 485,451 births to nulliparous women who experienced labor at or beyond 35 weeks of gestation in Alberta, Canada, from 1992 to 2018. The data were from a province-wide perinatal database. The primary outcome was cesarean delivery. Multivariate logistic regression and calculation of population attributable risk for identified risk factors were performed.

RESULTS

The cesarean delivery rate increased from 12.5% in 1992 to 24% in 2018. The prevalence of maternal risk factors for cesarean delivery such as obesity, maternal age 35 years or older at delivery, and comorbidities increased over the study period. However, this did not account for the increase in cesarean delivery, because the frequency of cesarean delivery increased irrespective of risk status. Additionally, the population-attributable risk for each risk factor was stable across the study period. For example, for maternal age 35 years or older at delivery, the number of cesarean deliveries attributable to this factor (the population-attributable risk) was 0.9 per 100 deliveries in 1992-1998 and 1 per 100 in 2014-2018. The proportion of cesarean deliveries in which nonreassuring fetal status was the indication increased from 30.1% in 1992 to 51.1% in 2018. The absolute rate of cesarean delivery in the second stage of labor increased from 3.1% in 1992 to 5.9% in 2018. This was due to a significant increase, among those who entered the second stage, in cesarean delivery without a trial of forceps, from 2.5% in 1992 to 7.0% in 2018.

CONCLUSION

The observed doubling of the rate of cesarean delivery in labor in first-time mothers was not driven by patient risk factors. Increases in the rate of cesarean delivery for nonreassuring fetal status and decreased operative vaginal deliveries were important factors.

How I treat venous thromboembolism in pregnancy

One to 2 pregnant women in 1000 will experience venous thromboembolism (VTE) during pregnancy or postpartum. Pulmonary embolism (PE) is a leading cause of maternal mortality, and deep vein thrombosis leads to maternal morbidity, with postthrombotic syndrome potentially diminishing quality of life for a woman's lifetime. However, the evidence base for pregnancy-related VTE management remains weak. Evidence-based guideline recommendations are often extrapolated from nonpregnant women and thus weak or conditional, resulting in wide variation of practice. In women with suspected PE, the pregnancy-adapted YEARS algorithm is safe and efficient, rendering computed tomographic pulmonary angiography to rule out PE unnecessary in 39%. Low molecular weight heparin (LMWH) in therapeutic doses is the treatment of choice during pregnancy, and anticoagulation (LMWH or vitamin K antagonists [VKAs]) should be continued until 6 weeks after delivery, with a 3-month minimum total duration. LMWH or VKA use does not preclude breastfeeding. Postpartum, direct oral anticoagulants are an option if a woman does not breastfeed and long-term use is intended. Management of delivery, including type of analgesia, requires a multidisciplinary approach and depends on local preferences and patient-specific conditions. Several options are possible, including waiting for spontaneous delivery with temporary LMWH interruption. Prophylaxis for recurrent VTE prevention in subsequent pregnancies is indicated in most women with a history of VTE.

Pulmonary Embolism in Pregnancy

Even though venous thromboembolism is a leading cause of maternal mortality in high-income countries, there are limited high-quality data to assist clinicians with the management of pulmonary embolism in this patient population. Diagnosis, prevention, and treatment of pregnancy-associated pulmonary embolism are complicated by the need to consider fetal, as well as maternal, well-being. Recent studies suggest that clinical prediction rules and D-dimer testing can reduce the need for diagnostic imaging in a subset of patients. Low-molecular-weight heparin is the preferred anticoagulant for both prophylaxis and treatment in this setting. Direct oral anticoagulants are contraindicated during pregnancy and in breastfeeding women. Thrombolysis or embolectomy should be considered for pregnant women with pulmonary embolism complicated by hemodynamic instability. Treatment of pregnancy-associated pulmonary embolism should be continued for at least 3 months, including 6 weeks postpartum. Management of anticoagulants at the time of delivery should involve a multidisciplinary individualized approach that uses shared decision making to take patient and caregiver values and preferences into account.

Early versus delayed oxytocin infusion following amniotomy for induction of labor: a meta-analysis of randomized controlled trials

BACKGROUND

Oxytocin infusion prior to confirmation of delay in labor is discouraged by the World Health Organization. However, evidence from the Cochrane library seems to support early amniotomy and oxytocin to reduce the rates of cesarean sections (CS).

OBJECTIVES

To investigate differences in mode of delivery among parturient receiving early versus delayed oxytocin infusion following amniotomy as a mean for augmentation of labor.

SEARCH STRATEGY

We searched Medline, Scopus, EMBASE, Cochrane Central Register of Controlled Trials and Google Scholar databases from inception till February 2020. Selection criteria: Randomized controlled trials.

DATA COLLECTION AND ANALYSIS

Data were collected using a modified Cochrane data collection form for intervention reviews. Meta-analysis was performed using the meta function in RStudio.

MAIN RESULTS

Five studies were included that involved 1.232 parturient. The meta-analysis did not reveal significant differences in the mode of delivery among women that were randomized to receive immediate oxytocin infusion and those that received delayed oxytocin infusion (operative vaginal delivery OR 1.14, 95% CI 0.48, 2.69) and CS OR 0.81, 95% CI 0.53, 1.25)). The interval from amniotomy to delivery was significantly smaller in the immediate oxytocin infusion group; however, prediction intervals were not significant.

CONCLUSIONS

The results of our meta-analysis suggest that there is no difference in the mode of delivery and interval from amniotomy to delivery when oxytocin is delayed for at least one hour following amniotomy. Taking in mind this information as well as current recommendations drawn from the WHO physicians should consider withholding oxytocin infusion at least until protracted labor is confirmed.

MicroRNAs 363 and 149 are differentially expressed in the maternal circulation preceding a diagnosis of preeclampsia

Preeclampsia is a pregnancy complication associated with angiogenic dysbalance, maternal endothelial dysfunction and end-organ injury. A predictive test to identify those who will develop preeclampsia could substantially decrease morbidity and mortality. MicroRNAs (miRs) are small RNA molecules involved in post-transcriptional gene regulation. We screened for circulating miRs differentially expressed at 36 weeks’ gestation in pregnancies before the development of preeclampsia. We used a case–control group (198 controls, 34 pre-preeclampsia diagnosis) selected from a prospective cohort (n = 2015) and performed a PCR-based microarray to measure the expression of 41 miRs. We found six circulating miRs (miRs 363, 149, 18a, 1283, 16, 424) at 36 weeks' had significantly reduced expression (p < 0.0001–0.04). miR363 was significantly downregulated at 28 weeks’ gestation, 10–12 weeks before the onset of clinical disease. In the circulation of another cohort of 34 participants with established preterm preeclampsia (vs 23 controls), we found miRs363, 18a, 149 and 16 were significantly down regulated (p < 0.0001–0.04). Combined expression of miRs149 and 363 in the circulation at 36 weeks’ gestation provides a test with 45% sensitivity (at a specificity of 90%) which suggests measuring both miRs may have promise as part of a multi-marker test to predict preeclampsia.

Trends in prevalence of pre-existing diabetes and perinatal outcomes: a large, population-based study in Catalonia, Spain, 2006-2015

INTRODUCTION

This study aims to assess trends in the prevalence of pre-existing diabetes and whether the risk of adverse perinatal outcomes decreased in women between 2006 and 2015 in Catalonia, Spain.

RESEARCH DESIGN AND METHODS

A population-based study of 743 762 singleton deliveries between 2006 and 2015 in Catalonia, Spain, was conducted using data from the Spanish Minimum Basic Data Set. Cases of type 1 diabetes (T1DM) and 'type 2 diabetes and other pre-existing diabetes' ('T2DM and other PGD') were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Crude and age-adjusted annual prevalences were calculated. Poisson regression model was used to assess trends in prevalence and perinatal outcomes during the study period.

RESULTS

Overall prevalences of pre-existing diabetes, T1DM and 'T2DM and other PGD' were 0.52% (95% CI 0.51 to 0.54), 0.17% (95% CI 0.17 to 0.18) and 0.35% (95% CI 0.33 to 0.36), respectively. From 2006 to 2015, rates increased for pre-existing diabetes (from 0.43 (95% CI 0.39 to 0.48) to 0.56% (0.50 to 0.62), p<0.001), T1DM (from 0.14 (0.11 to 0.17) to 0.20% (0.17 to 0.23), p<0.001) and 'T2DM and other PGD' (from 0.29 (0.25 to 0.33) to 0.36% (0.31 to 0.40), p<0.001). Pre-eclampsia rose in women with pre-existing diabetes (from 4.38% to 8.97%, adjusted p<0.001), T1DM (from 3.85% to 12.88%, p=0.005) and 'T2DM and other PGD' (from 4.63% to 6.78%, adjusted p=0.01). Prevalence of prematurity, cesarean section and small for gestational age remained stable in all diabetes groups. However, the prevalence of macrosomia fell in women with pre-existing diabetes (from 18.18% to 11.9%, adjusted p=0.011) and 'T2DM and other PGD' (from 14.71% to 11.06%, non-adjusted p=0.022, adjusted p=0.305) and large for gestational age decreased in all diabetes groups (from 39.73% to 30.25% in pre-existing diabetes, adjusted p=0.004).

CONCLUSIONS

The prevalence of pre-existing diabetes increased significantly in Catalonia between 2006 and 2015. Despite improvements in outcomes related to excessive birth weight, pre-eclampsia rates are rising and overall perinatal outcomes in women with pre-existing diabetes continue to be markedly worse than in the population without diabetes.

A survey of obstetricians' attitudes to induction of labour at 39 weeks gestation with the intention of reducing caesarean section rates

BACKGROUND

Induction of labour (IOL) and caesarean section (CS) rates continue to increase in Australia, New Zealand and globally. There is evidence that CS rates are decreased in the context of medically indicated and elective IOL; therefore, the emerging concept of using IOL as means of preventing CS warrants investigation.

AIMS

To assess obstetricians' opinions of elective IOL at 39 weeks gestation, its feasibility, generalisability and utility as a means of preventing CS in Australia and New Zealand.

MATERIALS AND METHODS

A de-identified cross-sectional survey was distributed electronically to all Fellows and trainees of The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). The survey was voluntary and distributed with the approval of the RANZCOG Continuing Education Committee. The survey addressed opinions relating to rates of and indications for IOL, the perceived validity of those indications and explored the acceptability of using a screening tool to predict women at increased risk of intra-partum CS and tailoring obstetric management to include the option of IOL at 39 weeks gestation.

RESULTS

The overall response rate was 34% (492/1423) (including trainees) and the response rate was 53% (394/750) for currently practising obstetricians. The majority (90%) of responders agreed on medical and clinical indications for IOL. There was no consensus on the validity of IOL if a woman were at apparent high risk of intra-partum CS; however, 81% (360/443) of clinicians would be interested in a tool that could predict those women at risk.

CONCLUSIONS

There is heterogeneity of obstetrician's beliefs on using IOL at 39 weeks as a mechanism to reduce the CS rate.

The Role of Oxytocin in Primary Cesarean Birth Among Low-Risk Women

INTRODUCTION

To examine whether there is a threshold of oxytocin exposure at which the risk for primary cesarean increases among women who are nulliparous with a term, singleton, vertex fetus (NTSV) and how oxytocin interacts with other risk factors to contribute to this outcome.

METHODS

This was a secondary analysis of the Consortium on Safe Labor data set that used a retrospective cohort study design. Women who met the criteria for NTSV who were not admitted for a prelabor cesarean and for whom oxytocin data were available, were included in the sample. Robust logistic regression was used to examine the association of oxytocin exposure with primary cesarean birth, while controlling for demographic and clinical risk factors and clustering by provider.

RESULTS

The sample comprised 17,331 women who were exposed to oxytocin during labor. The women were predominantly white non-Hispanic (59.2%) with an average (SD) gestational age of 39.4 (1.1) weeks and an 18.5% primary cesarean rate. Exposure to greater than 11,400-milliunits (mU) of oxytocin resulted in 1.6 times increased odds of primary cesarean birth compared with less than 11,400 mU (95% CI 1.01-2.6).

DISCUSSION

Exposure to greater than 11,400 mU of oxytocin in labor was associated with an increased odds of primary cesarean birth in NTSV women.

Maternal perceptions of the experience of attempted labor induction and medically elective inductions: analysis of survey results from listening to mothers in California

BACKGROUND

The rate of induction of labor in the U.S. has risen from 9.6% in 1990 to 25.7% in 2018, including 31.7% of first-time births. Recent studies that have examined inductions have been small qualitative studies or relied on either medical records or administrative data. This study examines induction from the perspective of those women who experienced it, with a particular focus on the prevalence and predictors of inductions for nonmedical indications, women's experience of pressure to induce labor and the relationship between the attempt to medically initiate labor and cesarean section.

METHODS

Study data are drawn from the 2119 respondents to the Listening to Mothers in California survey who were planning to have a vaginal birth in 2016. Mothers were asked if there had been an attempt to medically initiate labor, if it actually started labor, if they felt pressured to have the induction, if they had a cesarean and the reason for the induction. Reasons for induction were classified as either medically indicated or elective.

RESULTS

Almost half (47%) of our respondents indicated an attempt was made to medically induce their labor, and 71% of those attempts initiated labor. More than a third of the attempts (37%) were elective. Attempted induction overall was most strongly associated with giving birth at 41+ weeks (aOR 3.28; 95% C.I. 2.21-4.87). Elective inductions were more likely among multiparous mothers and in pregnancies at 39 or 40 weeks. The perception of being pressured to have labor induced was related to higher levels of education, maternal preference for less medical intervention in birth, having an obstetrician compared to a midwife and gestational ages of 41+ weeks. Cesarean birth was more likely in the case of overall induction (aOR 1.51; 95% C.I. 1.11-2.07) and especially following a failed attempt at labor induction (aOR 4.50; 95% C.I. 2.93-6.90).

CONCLUSION

Clinicians counselling mothers concerning the need for labor induction should be aware of mothers' perceptions about birth and engage in true shared decision making in order to avoid the maternal perception of being pressured into labor induction.

Oxytocin and emergency caesarean section in a mediumsized hospital in Pakistan: A cross-sectional study

INTRODUCTION

One of the most common complications during labor is prolonged labor (dystocia), which is associated with risks for the mother and fetus. Dystocia is usually treated with oxytocin, which is also used to induce labor. Oxytocin may not have the desired effect of progress and can negatively affect the fetus, thus resulting in an emergency caesarean section (CS). The aim of this study was to describe obstetric practice, use of oxytocin and its association with an emergency CS.

METHODS

A cross-sectional retrospective register study was conducted that included all women who gave birth during 2014 and 2015 at a hospital in a large city in Pakistan.

RESULTS

A total of 6652 women gave birth to 6767 newborns, 66.8% were multiparous and 33.2% primiparous women. Of the primiparous women, 78.9% had a spontaneous vaginal birth, 1.2% an elective CS and 14.4% an emergency CS. Of the multiparous women, 81.9% had a spontaneous vaginal birth, 8.0% an elective CS and 6.7% an emergency CS. Operative vaginal birth was 2.1% among primiparous and 0.2% among multiparous women. Oxytocin for induction or augmentation was administered to 60.0% of primiparous and 30.5% of multiparous women. Oxytocin during the first stage of labor was associated with an increased risk for emergency CS for both primiparous and multiparous women.

CONCLUSIONS

Despite the association between oxytocin and emergency CS, the CS rate was low in this hospital. The majority of the women gave birth vaginally, even with a breech presentation. Few operative vaginal births were performed.

Induction of labour at or beyond 37 weeks' gestation

BACKGROUND

Risks of stillbirth or neonatal death increase as gestation continues beyond term (around 40 weeks' gestation). It is unclear whether a policy of labour induction can reduce these risks. This Cochrane Review is an update of a review that was originally published in 2006 and subsequently updated in 2012 and 2018.

OBJECTIVES

To assess the effects of a policy of labour induction at or beyond 37 weeks' gestation compared with a policy of awaiting spontaneous labour indefinitely (or until a later gestational age, or until a maternal or fetal indication for induction of labour arises) on pregnancy outcomes for the infant and the mother.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (17 July 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) conducted in pregnant women at or beyond 37 weeks, comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour (expectant management). We also included trials published in abstract form only. Cluster-RCTs, quasi-RCTs and trials using a cross-over design were not eligible for inclusion in this review. We included pregnant women at or beyond 37 weeks' gestation. Since risk factors at this stage of pregnancy would normally require intervention, only trials including women at low risk for complications, as defined by trialists, were eligible. The trials of induction of labour in women with prelabour rupture of membranes at or beyond term were not considered in this review but are considered in a separate Cochrane Review.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. We assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

In this updated review, we included 34 RCTs (reporting on over 21,000 women and infants) mostly conducted in high-income settings. The trials compared a policy to induce labour usually after 41 completed weeks of gestation (> 287 days) with waiting for labour to start and/or waiting for a period before inducing labour. The trials were generally at low to moderate risk of bias. Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all-cause) perinatal deaths (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.15 to 0.64; 22 trials, 18,795 infants; high-certainty evidence). There were four perinatal deaths in the labour induction policy group compared with 25 perinatal deaths in the expectant management group. The number needed to treat for an additional beneficial outcome (NNTB) with induction of labour, in order to prevent one perinatal death, was 544 (95% CI 441 to 1042). There were also fewer stillbirths in the induction group (RR 0.30, 95% CI 0.12 to 0.75; 22 trials, 18,795 infants; high-certainty evidence); two in the induction policy group and 16 in the expectant management group. For women in the policy of induction arms of trials, there were probably fewer caesarean sections compared with expectant management (RR 0.90, 95% CI 0.85 to 0.95; 31 trials, 21,030 women; moderate-certainty evidence); and probably little or no difference in operative vaginal births with induction (RR 1.03, 95% CI 0.96 to 1.10; 22 trials, 18,584 women; moderate-certainty evidence). Induction may make little or difference to perineal trauma (severe perineal tear: RR 1.04, 95% CI 0.85 to 1.26; 5 trials; 11,589 women; low-certainty evidence). Induction probably makes little or no difference to postpartum haemorrhage (RR 1.02, 95% CI 0.91 to 1.15, 9 trials; 12,609 women; moderate-certainty evidence), or breastfeeding at discharge (RR 1.00, 95% CI 0.96 to 1.04; 2 trials, 7487 women; moderate-certainty evidence). Very low certainty evidence means that we are uncertain about the effect of induction or expectant management on the length of maternal hospital stay (average mean difference (MD) -0.19 days, 95% CI -0.56 to 0.18; 7 trials; 4120 women; Tau² = 0.20; I² = 94%). Rates of neonatal intensive care unit (NICU) admission were lower (RR 0.88, 95% CI 0.80 to 0.96; 17 trials, 17,826 infants; high-certainty evidence), and probably fewer babies had Apgar scores less than seven at five minutes in the induction groups compared with expectant management (RR 0.73, 95% CI 0.56 to 0.96; 20 trials, 18,345 infants; moderate-certainty evidence). Induction or expectant management may make little or no difference for neonatal encephalopathy (RR 0.69, 95% CI 0.37 to 1.31; 2 trials, 8851 infants; low-certainty evidence, and probably makes little or no difference for neonatal trauma (RR 0.97, 95% CI 0.63 to 1.49; 5 trials, 13,106 infants; moderate-certainty evidence) for induction compared with expectant management. Neurodevelopment at childhood follow-up and postnatal depression were not reported by any trials. In subgroup analyses, no differences were seen for timing of induction (< 40 versus 40-41 versus > 41 weeks' gestation), by parity (primiparous versus multiparous) or state of cervix for any of the main outcomes (perinatal death, stillbirth, NICU admission, caesarean section, operative vaginal birth, or perineal trauma).

AUTHORS' CONCLUSIONS

There is a clear reduction in perinatal death with a policy of labour induction at or beyond 37 weeks compared with expectant management, though absolute rates are small (0.4 versus 3 deaths per 1000). There were also lower caesarean rates without increasing rates of operative vaginal births and there were fewer NICU admissions with a policy of induction. Most of the important outcomes assessed using GRADE had high- or moderate-certainty ratings. While existing trials have not yet reported on childhood neurodevelopment, this is an important area for future research. The optimal timing of offering induction of labour to women at or beyond 37 weeks' gestation needs further investigation, as does further exploration of risk profiles of women and their values and preferences. Offering women tailored counselling may help them make an informed choice between induction of labour for pregnancies, particularly those continuing beyond 41 weeks - or waiting for labour to start and/or waiting before inducing labour.

Timing and mode of delivery with advancing maternal age

In 2017, 23% of all live births in the United Kingdom were to women aged over 35 years. Decisions around the timing of delivery for such women must balance the risks of prolongation of the pregnancy and of iatrogenic harm from timed delivery. Women of advanced maternal age have a small age-related elevated risk of term stillbirth. Antenatal monitoring and the route of delivery should not differ from those for younger women. The induction of labour at 39 weeks for such women does not appear to increase the risk of emergency caesarean section or to have any short-term adverse effects on mother or baby. There have been no studies on the long-term effects of induction in this group. Nevertheless, it seems reasonable to offer women of advanced maternal age, induction of labour at 39 weeks where resources are available to safely provide this.

Membrane sweeping for induction of labour

BACKGROUND

Induction of labour involves stimulating uterine contractions artificially to promote the onset of labour. There are several pharmacological, surgical and mechanical methods used to induce labour. Membrane sweeping is a mechanical technique whereby a clinician inserts one or two fingers into the cervix and using a continuous circular sweeping motion detaches the inferior pole of the membranes from the lower uterine segment. This produces hormones that encourage effacement and dilatation potentially promoting labour. This review is an update to a review first published in 2005.

OBJECTIVES

To assess the effects and safety of membrane sweeping for induction of labour in women at or near term (≥ 36 weeks' gestation).

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (25 February 2019), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (25 February 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing membrane sweeping used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed on a predefined list of labour induction methods. Cluster-randomised trials were eligible, but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, risk of bias and extracted data. Data were checked for accuracy. Disagreements were resolved by discussion, or by including a third review author. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 44 studies (20 new to this update), reporting data for 6940 women and their infants. We used random-effects throughout. Overall, the risk of bias was assessed as low or unclear risk in most domains across studies. Evidence certainty, assessed using GRADE, was found to be generally low, mainly due to study design, inconsistency and imprecision. Six studies (n = 1284) compared membrane sweeping with more than one intervention and were thus included in more than one comparison. No trials reported on the outcomes uterine hyperstimulation with/without fetal heart rate (FHR) change, uterine rupture or neonatal encephalopathy. Forty studies (6548 participants) compared membrane sweeping with no treatment/sham Women randomised to membrane sweeping may be more likely to experience: · spontaneous onset of labour (average risk ratio (aRR) 1.21, 95% confidence interval (CI) 1.08 to 1.34, 17 studies, 3170 participants, low-certainty evidence). but less likely to experience: · induction (aRR 0.73, 95% CI 0.56 to 0.94, 16 studies, 3224 participants, low-certainty evidence); There may be little to no difference between groups for: · caesareans (aRR 0.94, 95% CI 0.85 to 1.04, 32 studies, 5499 participants, moderate-certainty evidence); · spontaneous vaginal birth (aRR 1.03, 95% CI 0.99 to 1.07, 26 studies, 4538 participants, moderate-certainty evidence); · maternal death or serious morbidity (aRR 0.83, 95% CI 0.57 to 1.20, 17 studies, 2749 participants, low-certainty evidence); · neonatal perinatal death or serious morbidity (aRR 0.83, 95% CI 0.59 to 1.17, 18 studies, 3696 participants, low-certainty evidence). Four studies reported data for 480 women comparing membrane sweeping with vaginal/intracervical prostaglandins There may be little to no difference between groups for the outcomes: · spontaneous onset of labour (aRR, 1.24, 95% CI 0.98 to 1.57, 3 studies, 339 participants, low-certainty evidence); · induction (aRR 0.90, 95% CI 0.56 to 1.45, 2 studies, 157 participants, low-certainty evidence); · caesarean (aRR 0.69, 95% CI 0.44 to 1.09, 3 studies, 339 participants, low-certainty evidence); · spontaneous vaginal birth (aRR 1.12, 95% CI 0.95 to 1.32, 2 studies, 252 participants, low-certainty evidence); · maternal death or serious morbidity (aRR 0.93, 95% CI 0.27 to 3.21, 1 study, 87 participants, low-certainty evidence); · neonatal perinatal death or serious morbidity (aRR 0.40, 95% CI 0.12 to 1.33, 2 studies, 269 participants, low-certainty evidence). One study, reported data for 104 women, comparing membrane sweeping with intravenous oxytocin +/- amniotomy There may be little to no difference between groups for: · spontaneous onset of labour (aRR 1.32, 95% CI 88 to 1.96, 1 study, 69 participants, low-certainty evidence); · induction (aRR 0.51, 95% CI 0.05 to 5.42, 1 study, 69 participants, low-certainty evidence); · caesarean (aRR 0.69, 95% CI 0.12 to 3.85, 1 study, 69 participants, low-certainty evidence); · maternal death or serious morbidity was reported on, but there were no events. Two studies providing data for 160 women compared membrane sweeping with vaginal/oral misoprostol There may be little to no difference between groups for: · caesareans (RR 0.82, 95% CI 0.31 to 2.17, 1 study, 96 participants, low-certainty evidence). One study providing data for 355 women which compared once weekly membrane sweep with twice-weekly membrane sweep and a sham procedure There may be little to no difference between groups for: · induction (RR 1.19, 95% CI 0.76 to 1.85, 1 study, 234 participants, low-certainty); · caesareans (RR 0.93, 95% CI 0.60 to 1.46, 1 study, 234 participants, low-certainty evidence); · spontaneous vaginal birth (RR 1.00, 95% CI 0.86 to 1.17, 1 study, 234 participants, moderate-certainty evidence); · maternal death or serious maternal morbidity (RR 0.78, 95% CI 0.30 to 2.02, 1 study, 234 participants, low-certainty evidence); · neonatal death or serious neonatal perinatal morbidity (RR 2.00, 95% CI 0.18 to 21.76, 1 study, 234 participants, low-certainty evidence); We found no studies that compared membrane sweeping with amniotomy only or mechanical methods. Three studies, providing data for 675 women, reported that women indicated favourably on their experience of membrane sweeping with one study reporting that 88% (n = 312) of women questioned in the postnatal period would choose membrane sweeping in the next pregnancy. Two studies reporting data for 290 women reported that membrane sweeping is more cost-effective than using prostaglandins, although more research should be undertaken in this area.

AUTHORS' CONCLUSIONS

Membrane sweeping may be effective in achieving a spontaneous onset of labour, but the evidence for this was of low certainty. When compared to expectant management, it potentially reduces the incidence of formal induction of labour. Questions remain as to whether there is an optimal number of membrane sweeps and timings and gestation of these to facilitate induction of labour.

Cesarean delivery: Trend in indications over three decades within a major city hospital network

INTRODUCTION

The cesarean delivery rate has been increasing globally in recent decades. The reasons for this are complex and subject to ongoing debate. Investigation of the indications for cesarean delivery and how these have changed over an extended period of time could provide insight into the reasons for changing obstetric practice. Our objective was to explore contributing factors to the increasing rate of cesarean delivery by examining the incidence of and indications for cesarean delivery over the past three decades at our institutions.

MATERIAL AND METHODS

We conducted a retrospective observational study of all cesarean deliveries, from 24 weeks' gestational age onwards, within an inner-city hospital network in Sydney, Australia, between August 1989 and December 2016. The primary outcome measures were the rates of and indications for emergency and planned cesarean delivery. We also examined our data within the Robson 10-Group Classification system.

RESULTS

There were 147 722 births over the study period, with 37 309 cesarean deliveries for an overall rate of 25.3%. The rate of cesarean delivery increased from 18.7% in 1989-1994 (8.7% emergency, 10% planned) to 30.4% in 2010-2016 (11.4% emergency, 19% planned). Emergency cesarean delivery for slow progress increased from 3.4% to 5.5% of all births (a relative increase of 62%) and other emergency cesareans mainly performed for suspected intrapartum fetal compromise increased from 5.2% to 5.6% (a relative increase of 8%). Previous uterine surgery (predominantly cesarean section) was the largest contributor to the increase in planned procedures from 3.8% to 9.0% of all births, and 29% of all cesarean deliveries. Primary cesarean delivery for planned antenatal fetal indications, previous pregnancy problems, multiple gestation and maternal choice all increased substantially in combined rate from 0.7% to 4.9%. Cesarean rates in Robson groups 6, 7 and 8 (term breech and multiple gestations) increased most over time.

CONCLUSIONS

The increased rate of cesarean delivery is mainly attributable to a greater number of procedures performed for slow progress in labor, breech presentation or repeat cesarean section.

Time and mode of delivery in diabetic pregnancy: a review

The review presents some renewed data on the problem of optimal time and modes of delivery for women with various types of diabetes mellitus (DM 1 and 2, gestational diabetes). The necessity of making the universal delivery strategy algorithm for women with DM comes out of adverse outcomes high frequency, where the main cases are fetal macrosomia, fetal shoulder dystocia and perinatal mortality. Despite significant interest for this issue, there is still no common delivery tactics in the world for pregnant women with carbohydrate metabolism disorders. The main obstacle is evidence-based tests and meta-analysis insufficiency. So far, further studies are necessary to obtain high quality data concerning optimal terms and modes of delivery for women with DM.

Clinical interventions that influence vaginal birth after cesarean delivery rates: Systematic Review & Meta-Analysis

BACKGROUND

To systematically review the literature on clinical interventions that influence vaginal birth after cesarean (VBAC) rates.

METHODS

We searched Ovid Medline, Ovid Embase, Wiley Cochrane Library, CINAHL via EBSCOhost; and Ovid PsycINFO. Additional studies were identified by searching for clinical trial records, conference proceedings and dissertations. Limits were applied for language (English and French) and year of publication (1985 to present). Two reviewers independently screened comparative studies (randomized or non-randomized controlled trials, and observational designs) according to a priori eligibility criteria: women with prior cesarean sections; any clinical intervention or exposure intended to increase the VBAC rate; any comparator; and, outcomes reporting VBAC, uterine rupture and uterine dehiscence rates. One reviewer extracted data and a second reviewer verified for accuracy. Meta-analysis was conducted using Mantel-Haenszel (random effects model) relative risks (VBAC rate) and risk differences (uterine rupture and dehiscence). Two reviewers independently conducted methodological quality assessments using the Mixed Methods Appraisal Tool (MMAT).

RESULTS

Twenty-nine studies (six trials and 23 cohorts) examined different clinical interventions affecting rates of vaginal deliveries among women with a prior cesarean delivery (CD). Methodological quality was good overall for the trials; however, concerns among the cohort studies regarding selection bias, comparability of groups and outcome measurement resulted in higher risk of bias. Interventions for labor induction, with or without cervical ripening, included pharmacologic (oxytocin, prostaglandins, misoprostol, mifepristone, epidural analgesia), non-pharmacologic (membrane sweep, amniotomy, balloon devices), and combined (pharmacologic and non-pharmacologic). Single studies with small sample sizes and event rates contributed to most comparisons, with no clear differences between groups on rates of VBAC, uterine rupture and uterine dehiscence.

CONCLUSIONS

This systematic review evaluated clinical interventions directed at increasing the rate of vaginal delivery among women with a prior CD and found low to very low certainty in the body of evidence for cervical ripening and/or labor induction techniques. There is insufficient high-quality evidence to inform optimal clinical interventions among women attempting a trial of labor after a prior CD.

The risk of cesarean delivery after labor induction among women with prior pregnancy complications: a subgroup analysis of the AFFIRM study

Background

To determine the risk of cesarean delivery after labor induction among patients with prior placenta-mediated pregnancy complications (pre-eclampsia, late pregnancy loss, placental abruption or intrauterine growth restriction).

Methods

The AFFIRM database includes patient level data from 9 randomized controlled trials that evaluated the role of LMWH versus no LMWH during pregnancy to prevent recurrent placenta-mediated pregnancy complications. The primary outcome of this sub-study was the proportion of women who had an unplanned cesarean delivery after induction of labor compared to after spontaneous labor.

Results

There were 512 patients from 7 randomized trials included in our sub-study. There was no difference in the risk of cesarean delivery between women with labor induction (21/148, 14.2%) and spontaneous labor (79/364, 21.7%) (odds ratio (OR) 0.60, 95% CI, 0.35–1.01; p = 0.052). Among 274 women who used LMWH prophylaxis during pregnancy, the risk of cesarean delivery was lower among those that underwent labor induction (9.8%) compared to spontaneous labor (22.4%) (OR 0.38, 95% CI, 0.17–0.84; p = 0.01).

Conclusions

The risk of cesarean delivery is not increased after labor induction among a higher risk patient population with prior pregnancy complications. Our results suggest that women who receive LMWH during pregnancy might benefit from labor induction.

Effect of premature rupture of membranes on time to delivery and outcomes in full-term pregnancies with vaginal dinoprostone-induced labour

OBJECTIVE

The aim of this study was to assess the effect of premature rupture of membranes (PROM) in full-term pregnancies with dinoprostone-induced labour.

PATIENTS AND METHODS

This historical cohort study analysed 2166 full-term pregnancies with dinoprostone-induced labour between 1 August 2016 and 30 April 2018. A group that underwent induction of labour for PROM (PROM group) was compared to a group that underwent labour induction for other indications (no-PROM group). Time to delivery and perinatal outcome were compared between the two groups.

RESULTS

A total of 2166 pregnancies (662 PROM and 1504 no-PROM) were included. The two groups demonstrated no significant differences except in biparietal diameter and gestational age (P < 0.001). The caesarean section delivery rate in the PROM group was significantly lower than in the non-PROM group (26.89 vs. 33.58%, P < 0.0001). In the PROM group, the induction-to-delivery time was shorter (P < 0.0001) and the rates of vaginal birth within 24 h (P < 0.0001) and 48 h (P < 0.0001) were higher than those in the control group. The incidence rate of amniotic fluid contamination in the PROM group was significantly lower than that in the non-PROM group (19.18 vs. 25.20%, P = 0.002).

CONCLUSION

PROM significantly affects perinatal outcome in Chinese women who undergo dinoprostone-induced labour, especially the caesarean delivery rate and the induction-to-delivery time.

Medical and non-medical reasons for cesarean section delivery in Egypt: a hospital-based retrospective study

Background

Caesarean section (CS) is an important lifesaving intervention that can reduce maternal and newborn morbidity and mortality. The dramatic increase in CS rates globally has prompted concerns that the procedure may be overused or used for inappropriate indications. In Egypt, CS rates are alarmingly high, accounting for 52% of all deliveries. This study sought to (1) explore indications and risk factors for CS in public hospitals in four governorates in Egypt and (2) examine health care provider factors impacting the decision to perform a CS.

Methods

We reviewed medical records for all deliveries that took place during April 2016 in 13 public hospitals situated in four governorates in Egypt (Cairo, Alexandria, Assiut and Behera), and extracted information pertaining to medical indications and women’s obstetric characteristics. We also interviewed obstetricians in the study hospitals to explore factors associated with the decision to perform CS.

Results

A total of 4357 deliveries took place in the study hospitals during that period. The most common medical indications were previous CS (50%), an “other” category (13%), and fetal distress (9%). Multilevel analysis revealed that several obstetric risk factors were associated with increased odds of CS mode of delivery – including previous CS, older maternal age, and nulliparity – while factors such as partograph completion and oxytocin use were associated with reduced odds of CS. Interviews with obstetricians highlighted non-medical factors implicated in the high CS rates, including a convenience incentive, lack of supervision and training in public hospitals, as well as absence of or lack of familiarity with clinical guidelines.

Conclusion

A combination of both medical and non-medical factors drives the increase in CS rates. Our analysis however suggests that a substantial number of CS deliveries took place in the absence of strong medical justification. Health care provider factors seem to be powerful factors influencing CS rates in the study hospitals.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy

BACKGROUND

Venous thromboembolism (VTE) complicates ∼1.2 of every 1000 deliveries. Despite these low absolute risks, pregnancy-associated VTE is a leading cause of maternal morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and others in decisions about the prevention and management of pregnancy-associated VTE.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The panel agreed on 31 recommendations related to the treatment of VTE and superficial vein thrombosis, diagnosis of VTE, and thrombosis prophylaxis.

CONCLUSIONS

There was a strong recommendation for low-molecular-weight heparin (LWMH) over unfractionated heparin for acute VTE. Most recommendations were conditional, including those for either twice-per-day or once-per-day LMWH dosing for the treatment of acute VTE and initial outpatient therapy over hospital admission with low-risk acute VTE, as well as against routine anti-factor Xa (FXa) monitoring to guide dosing with LMWH for VTE treatment. There was a strong recommendation (low certainty in evidence) for antepartum anticoagulant prophylaxis with a history of unprovoked or hormonally associated VTE and a conditional recommendation against antepartum anticoagulant prophylaxis with prior VTE associated with a resolved nonhormonal provoking risk factor.

Use of labor induction with dinoprostone vaginal suppositories in pregnant women with gestational hypertension

AIM

Gestational hypertension is a common disorder of pregnancy. This study aims to evaluate the effect of labor induction with dinoprostone vaginal suppositories (Propess) on pregnancy outcomes in pregnant women with gestational hypertension.

METHODS

The retrospective study included 375 patients with gestational hypertension. All patients were included into three groups according to the characteristics at admission. Women who had initiated labor spontaneously at admission were enrolled in Spontaneous labor group. According to Bishop score, other patients underwent labor induction with Propess or oxytocin were enrolled in Propess group or Oxytocin group. Demographic information and perinatal outcome data were collected.

RESULTS

The vaginal delivery rate of the women with gestational hypertension was respectively 93.5% (Spontaneous labor group), 77.0% (Propess group), and 52.5% (Oxytocin group) in three groups with significant difference (P < 0.001). The duration of labor was 8.29 ± 3.70 h (Spontaneous labor group), 8.45 ± 5.21 h (Propess group) and 12.37 ± 11.47 h (Oxytocin group) in three groups, respectively. No differences were found in the intrapartum fever (P = 0.588), intrapartum hemorrhage (P = 0.953), intrapartum maximum blood pressure (P = 0.301 and P = 0.535) and post-partum hemorrhage (P = 0.075) among three groups. Neonatal outcomes were similar among three groups (Neonatal hospitalization rate, P = 0.437; 1-min Apgar score, P = 0.304; 5-min Apgar score, P = 0.340; Birth weight, P = 0.089). No poor maternal and neonatal outcomes occurred.

CONCLUSION

Pregnant women with gestational hypertension could have favorable pregnancy outcomes. Using Propess as a mode of labor induction in gestational hypertension is safe and effective, without increasing intrapartum blood pressure and inducing poor pregnancy outcomes.

The association between induction of labour at 38 to 39 weeks pregnancy and indication for caesarean delivery: An observational study

BACKGROUND

Induction of labour is associated with a reduction in caesarean delivery, but the mechanism of action and which groups of women might benefit remain unknown.

AIMS

To assess the association between induction of labour at 38-39 weeks pregnancy, and caesarean delivery: (i) overall; (ii) for slow progress in labour; and (iii) for suspected fetal compromise.

MATERIAL AND METHODS

Retrospective observational study in two Sydney hospitals from 2009 to 2016, among nulliparous women with induction of labour at 38 or 39 completed weeks pregnancy and a singleton, cephalic presenting fetus. The comparator was all planned vaginal births beyond 39^(+1/7) weeks, whether or not labour was induced. Binary and multinomial multiple logistic regressions adjusting for multiple confounders were performed.

RESULTS

There were 2388 and 15 259 women in the study and comparison groups respectively. Induction of labour was associated with caesarean delivery overall only for women <25 years of age (adjusted odds ratio 1.63; 95% CI 1.17-2.27) and was not associated with caesarean delivery for slow progress. Induction of labour was positively associated with increased caesarean delivery for suspected fetal compromise among young women (<30 years), with the association weakening as maternal age increased. The association between induction of labour and caesarean delivery was different for slow progress compared with suspected compromise (P = 0.005).

CONCLUSIONS

Induction of labour has different effects on the likelihood of caesarean delivery for slow progress and for suspected fetal compromise. Women <30 years of age are at higher risk of caesarean delivery for suspected fetal compromise, potentially due to uterine hyperstimulation.

Induction of labour: Experiences of care and decision-making of women and clinicians

BACKGROUND

There has been a rise in induction of labour over recent decades. There is some tension in the literature in relation to when induction is warranted and when not, with variability between guidelines and practice. Given these tensions, the importance of shared decision-making between clinicians and women is increasingly highlighted as paramount, but it remains unclear to what extent this occurs in routine care.

METHOD

Using a scoping review methodology, quantitative and qualitative evidence were considered to answer the research question "What are the views, preferences and experiences of women and clinicians in relation to induction of labour more broadly, and practices of decision-making specifically?" To identify studies, the databases PubMed, Maternity and Infant Care, CINAHL and EMBASE were searched from 2008 to 2018, and reference lists of included studies were examined.

FINDINGS

20 papers met inclusion criteria, in relation to (a) women's preferences, experiences and satisfaction with IOL; (b) women's experience of shared-decision making in relation to induction; (c) interventions that improve shared decision-making and (d) factors that influence decision-making from the perspective of clinicians. Synthesis of the included studies indicates that decision-making in relation to induction of labour is largely informed by medical considerations. Women are not routinely engaged in the decision making process with expectations and preferences largely unmet.

CONCLUSION

There is a need to develop strategies such as decision aids, the redesign of antenatal classes, and clinician communication training to improve the quality of information available to women and their capacity for informed decision-making.

The Robson 10-group classification in Iceland: Obstetric interventions and outcomes

BACKGROUND

Rising cesarean rates call for studies on which subgroups of women contribute to the rising rates, both in countries with high and low rates. This study investigated the cesarean rates and contributing groups in Iceland using the Robson 10-group classification system.

METHODS

This study included all births in Iceland from 1997 to 2015, identified from the Icelandic Medical Birth Registry (81 839). The Robson distribution, cesarean rate, and contribution of each Robson group were analyzed for each year, and the distribution of other outcomes was calculated for each Robson group.

RESULTS

The overall cesarean rate in the population was 16.4%. Robson groups 1 (28.7%) and 3 (38.0%) (spontaneous term births) were the largest groups, and groups 2b (0.4%) and 4b (0.7%) (prelabor cesareans) were small. The cesarean rate in group 5 (prior cesarean) was 55.5%. Group 5 was the largest contributing group to the overall cesarean rate (31.2%), followed by groups 1 (17.1%) and 2a (11.0%). The size of groups 2a (RR 1.04 [95% CI 1.01-1.08]) and 4a (RR 1.04 [95% CI 1.01-1.07]) (induced labors) increased over time, whereas their cesarean rates were stable (group 2a: P = 0.08) or decreased (group 4a: RR 0.95 [95% CI 0.91-0.98]).

CONCLUSIONS

In comparison with countries with high cesarean rates, the prelabor cesarean groups (singleton term pregnancies) in Iceland were small, and in women with a previous cesarean, the cesarean rate was low. The size of the labor induction group increased, yet the cesarean rate in this group did not increase.

A comparison of machine learning algorithms and covariate balance measures for propensity score matching and weighting

Propensity score matching (PSM) and propensity score weighting (PSW) are popular tools to estimate causal effects in observational studies. We address two open issues: how to estimate propensity scores and assess covariate balance. Using simulations, we compare the performance of PSM and PSW based on logistic regression and machine learning algorithms (CART; Bagging; Boosting; Random Forest; Neural Networks; naive Bayes). Additionally, we consider several measures of covariate balance (Absolute Standardized Average Mean (ASAM) with and without interactions; measures based on the quantile-quantile plots; ratio between variances of propensity scores; area under the curve (AUC)) and assess their ability in predicting the bias of PSM and PSW estimators. We also investigate the importance of tuning of machine learning parameters in the context of propensity score methods. Two simulation designs are employed. In the first, the generating processes are inspired to birth register data used to assess the effect of labor induction on the occurrence of caesarean section. The second exploits more general generating mechanisms. Overall, among the different techniques, random forests performed the best, especially in PSW. Logistic regression and neural networks also showed an excellent performance similar to that of random forests. As for covariate balance, the simplest and commonly used metric, the ASAM, showed a strong correlation with the bias of causal effects estimators. Our findings suggest that researchers should aim at obtaining an ASAM lower than 10% for as many variables as possible. In the empirical study we found that labor induction had a small and not statistically significant impact on caesarean section.

Trend in cesarean delivery rate among twin pregnancies over a 20 years epoch and the accompanied maternal and perinatal outcomes

Objective

To examine the trend of cesarean delivery (CD) rate among twin pregnancies and the trend in maternal and neonatal morbidities within two decades.

Study design

Population-based cohort study, conducted at a single teaching hospital in Israel on data between January 1995 and December 2015. All pregnant women with twin gestation who delivered at a gestational age of 24 weeks or more were included. Data on mode of deliveries, Apgar score <7 at 5 min, cord artery pH < 7.1, early postpartum hemorrhage, blood transfusion, and intrapartum fever for each year were extracted and plotted, and trends were analyzed. CDs performed for one or both twins were divided to laboring, i.e., after a trial of labor, and non-laboring CDs. Data was obtained from the hospital discharge register with ICD-9 codes and crosschecked with the labor medical records. The Cochran-Armitage Trend Test was used to identify trends and correlations.

Results

Of all 88,145 deliveries that took place during this period, 1955 (2.2%) were twins. Of these 53 were ineligible and were excluded. There was a statistically significant trend (increase) in twins birth over time (p = 0.004). CD rate increased significantly from 43.4% in 1995 to 66.0% in 2015 (p = 0.001). This increase was observed only among non-laboring cesareans (p = 0.001). Multivariate logistic regression analysis revealed that maternal and early neonatal morbidities examined did not differ significantly during the study period.

Conclusion

Non-laboring CD rate increased significantly over the past two decades among twin pregnancies. Despite this increase, maternal and early neonatal morbidities did not change.

Delivery or expectant management for prevention of adverse maternal and neonatal outcomes in hypertensive disorders of pregnancy: an individual participant data meta-analysis

OBJECTIVE

Hypertensive disorders affect 3-10% of pregnancies. Delayed delivery carries maternal risks, while early delivery increases fetal risk, so appropriate timing is important. The aim of this study was to compare immediate delivery with expectant management for prevention of adverse maternal and neonatal outcomes in women with hypertensive disease in pregnancy.

METHODS

CENTRAL, PubMed, MEDLINE and ClinicalTrials.gov were searched for randomized controlled trials comparing immediate delivery to expectant management in women presenting with gestational hypertension or pre-eclampsia without severe features from 34 weeks of gestation. The primary neonatal outcome was respiratory distress syndrome (RDS) and the primary maternal outcome was a composite of HELLP syndrome and eclampsia. The PRISMA-IPD guideline was followed and a two-stage meta-analysis approach was used. Relative risks (RR) and numbers needed to treat or harm (NNT/NNH) with 95% CI were calculated to evaluate the effect of the intervention.

RESULTS

Main outcomes were available for 1724 eligible women. Compared with expectant management, immediate delivery reduced the composite risk of HELLP syndrome and eclampsia in all women (0.8% vs 2.8%; RR, 0.33 (95% CI, 0.15-0.73); I2  = 0%; NNT, 51 (95% CI, 31.1-139.3)) as well as in the pre-eclampsia subgroup (1.1% vs 3.5%; RR, 0.39 (95% CI, 0.15-0.98); I2  = 0%). Immediate delivery increased RDS risk (3.4% vs 1.6%; RR, 1.94 (95% CI 1.05-3.6); I2  = 24%; NNH, 58 (95% CI, 31.1-363.1)), but depended upon gestational age. Immediate delivery in the 35th week of gestation increased RDS risk (5.1% vs 0.6%; RR, 5.5 (95% CI, 1.0-29.6); I2  = 0%), but immediate delivery in the 36th week did not (1.5% vs 0.4%; RR, 3.4 (95% CI, 0.4-30.3); I2 not applicable).

CONCLUSION

In women with hypertension in pregnancy, immediate delivery reduces the risk of maternal complications, whilst the effect on the neonate depends on gestational age. Specifically, women with a-priori higher risk of progression to HELLP, such as those already presenting with pre-eclampsia instead of gestational hypertension, were shown to benefit from earlier delivery. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.