Labor Progression and Risk of Cesarean Delivery in Electively Induced Nulliparas

Induction of labor and cesarean birth in lower-risk nulliparous women at term: A retrospective cohort study

OBJECTIVE

To evaluate whether induction of labor (IOL) is associated with cesarean birth (CB) and perinatal mortality in uncomplicated first births at term compared with expectant management outside the confines of a randomized controlled trial.

METHODS

Population-based retrospective cohort study of all births in Victoria, Australia, from 2010 to 2018 (n = 640,191). Preliminary analysis compared IOL at 37 weeks with expectant management at that gestational age and beyond for uncomplicated pregnancies. Similar comparisons were made for IOL at 38, 39, 40, and 41 weeks of gestation and expectant management. The primary analysis repeated these comparisons, limiting the population to nulliparous women with uncomplicated pregnancies and excluding those with a medical indication for IOL. We compared perinatal mortality between groups using Chi-square tests and multivariable logistic regression for all other comparisons. Adjusted odds ratios and 99% confidence intervals were reported. p < 0.01 denoted statistical significance.

RESULTS

Among nulliparous, uncomplicated pregnancies at ≥37 weeks of gestation in Victoria, IOL increased from 24.6% in 2010 to 30.0% in 2018 (p < 0.001). In contrast to the preliminary analysis, the primary analysis showed that IOL in lower-risk nulliparous women was associated with increased odds of CB when performed at 38 (aOR 1.23(1.13-1.32)), 39 (aOR 1.31(1.23-1.40)), 40 (aOR 1.42(1.35-1.50)), and 41 weeks of gestation (aOR 1.43(1.35-1.51)). Perinatal mortality was rare in both groups and non-significantly lower in the induced group at most gestations.

DISCUSSION

For lower-risk nulliparous women, the odds of CB increased with IOL from 38 weeks of gestation, along with decreased odds of perinatal mortality at 41 weeks only.

Two different regimens of outpatient Foley catheter induction of labor in nulliparas: A randomized trial

OBJECTIVES

To evaluate expectant compared to immediate return to hospital upon outpatient Foley catheter expulsion predicated on maternal satisfaction and amniotomy-titrated oxytocin infusion to delivery interval.

METHODS

This randomized trial was conducted in a tertiary university hospital in Malaysia from September 2020 to February 2022. A total of 330 nulliparous women at term with unripe cervices (Bishop score ≤5), singleton viable fetus in cephalic presentation, reassuring preinduction fetal heart rate tracing and intact membranes who underwent planned outpatient Foley catheter induction of labor (IOL) were included. Women were randomized to expectant or immediate return to hospital if the Foley was spontaneously expelled at home before their scheduled hospital admission the following day. Primary outcomes were amniotomy-titrated oxytocin infusion to delivery interval and maternal satisfaction on the induction process (assessed by 0-10 visual numerical rating scale [VNRS]).

RESULTS

Amniotomy-titrated oxytocin infusion to delivery interval was 8.7 ± 4.1 versus 8.9 ± 3.9 h, P = 0.605 (mean difference - 0.228 95% CI: -1.1 to +0.6 h) and maternal satisfaction VNRS score was median (interquartile range) 8 (7-9) versus 8 (7-9), P = 0.782. Early return to hospital rates were 37/165 (22.4%) versus 72/165 (43.6%), RR 0.51 (95% CI: 0.37-0.72), P ≤ 0.001, Cesarean delivery rates were 80/165 (48.5%) versus 80/165 (48.5%), RR 1.00 (95% CI: 0.80-1.25), P = 1.00 and duration of hospital stay was 54.4 ± 22.9 versus 56.7 ± 22.8 h, P = 0.364 for the expectant versus immediate return groups respectively.

CONCLUSION

In outpatient Foley catheter IOL, expectant compared to immediate return to hospital following Foley dislodgement results in similarly high maternal satisfaction. The amniotomy-titrated oxytocin to delivery duration is non-inferior with expectant management.

Neonatal outcomes of elective labor induction in low-risk term pregnancies

The rate of labor induction has increased in recent years. The results of previously conducted studies examining associations between elective induction of labor (IOL) and neonatal outcomes have been contradictory. The aim of this study was to examine the intrinsic neonatal risks following IOL. We conducted a population-based cohort study, including all women with recorded low-risk singleton pregnancies at a gestational age between 37 + 0 and 41 + 6 weeks in Sweden from 1999 to 2017. Data were collected from the Swedish Medical Birth register. Two study groups were compared-the elective induction group with the spontaneous labor onset group. The results showed that the rate of elective IOL increased from 7.2% in 1999 to 16.4% in 2017. Elective IOL was associated with a higher OR for chorioamnionitis, bacterial sepsis, intracranial hemorrhage, assisted ventilation, hyperbilirubinemia, APGAR < 7 at 5 min, and neonatal seizures compared to deliveries with spontaneous labor onset. Regarding mortality outcomes, no significant differences were shown between the groups for either early term or full-term deliveries. We conclude that IOL is associated with neonatal complications, although causality could not be established in this observational study. It is important to be aware of the increased risk and perform IOL with caution.

Membrane Sweeping to Induce Labor in Post-term Pregnant Women: Success Rate and Outcomes

Introduction Membrane sweeping is a mechanical technique by which a clinician inserts one or two fingers into the cervix and detaches the inferior pole of the membranes from the lower uterine segment using a continuous circular sweeping motion. This produces hormones that promote effacement and dilatation, potentially promoting labor. This study aimed to determine the success rate and the outcome of membrane sweeping in postdate pregnant women in Alhasahesa Teaching Hospital.  Methods This prospective descriptive cross-sectional study conducted at Alhashesa Teaching Hospital, Alhashesa, Sudan, between May and October 2022 included all pregnant women at 40 or more weeks of gestation who underwent membrane sweeping to induce labor. We recorded the number of sweeps needed, sweeping-to-delivery interval, mode of delivery, maternal outcome, and fetal outcome (including birth weight, Apgar score at delivery, and the need for neonatal intensive care unit admission [NICU]). Data were collected through patient interviews using a specially designed questionnaire and analyzed using Statistical Package for Social Sciences (SPSS®) software for Windows, Version 26.0 (Armonk, NY: IBM Corp.), Results Membrane sweeping induced labor in 127 postdate women (86.4%). Most of the women in the study (n=138; 93.9%) had no complications, seven (4.8%) had postpartum hemorrhage, one (0.7%) had sepsis, and one (0.7%) was admitted to the intensive care unit. All neonates were alive, and most (n=126; 85.8%) birth weights ranged from 2.5 kg to 3.5 kg. Thirteen (8.8%) neonates weighed less than 2.5 kg, and eight (5.4%) weighed more than 3.5 kg. One hundred thirty-three (90.5%) had Apgar scores <7, eight (5.4%) had Apgar scores under five, and six (4.1%) had Apgar scores of five to six. Seven neonates (4.8%) were admitted to the NICU. Conclusions Membrane sweeping to induce labor has a high success rate, and it can be safe for both the mother and the baby, as it is associated with a low rate of maternal and fetal complications. Additionally, no maternal and/or fetal deaths were reported. A large, controlled study is required to compare its benefits over other methods of induction of labor.

Put your weight behind it-Effect of body mass index on the active second stage of labour: A retrospective cohort study

OBJECTIVE

To explore the duration of the active phase of the second stage of labour in relation to maternal pre-pregnant body mass index (BMI).

DESIGN

Retrospective cohort study.

SETTING

Labour wards of three Norwegian university hospitals, 2012-2019.

POPULATION

Nulliparous and parous women without previous caesarean section with a live singleton fetus in cephalic presentation and spontaneous onset of labour, corresponding to the Ten Group Classification System (TGCS) group 1 and 3.

METHODS

Women were stratified to BMI groups according to WHO classification, and estimated median duration of the active phase of the second stage of labour was calculated using survival analyses. Caesarean sections and operative vaginal deliveries during the active phase were censored.

MAIN OUTCOME MEASURES

Estimated median duration of the active phase of second stage of labour.

RESULTS

In all, 47 942 women were included in the survival analyses. Increasing BMI was associated with shorter estimated median duration of the active second stage in both TGCS groups. In TGCS group 1, the estimated median durations (interquartile range) were 44 (26-75), 43 (25-71), 39 (22-70), 33 (18-63), 34 (19-54) and 29 (16-56) minutes in BMI groups 1-6, respectively. In TGCS group 3, the corresponding values were 11 (6-19), 10 (6-17), 10 (6-16), 9 (5-15), 8 (5-13) and 7 (4-11) minutes. Increasing BMI remained associated with shorter estimated median duration in analyses stratified by oxytocin augmentation and epidural analgesia.

CONCLUSION

Increasing BMI was associated with shorter estimated median duration of the active second stage of labour.

Elective Induction of Labour at 39 Weeks Compared With Expectant Management in Nulliparous Persons Delivering in a Community Hospital

OBJECTIVE

To determine the impact of offering elective labour induction at 39 weeks gestation on perinatal and maternal outcomes in nulliparous people with low-risk pregnancies.

METHODS

The charts of all pregnant people who delivered at Brockville General Hospital between September 2018 and December 2021 were retrospectively reviewed. Perinatal and maternal outcomes of low-risk nulliparous pregnant people who underwent elective induction at 39 weeks and over were extracted and compared with those of low-risk nulliparous pregnant people who underwent expectant management. Exclusion criteria included multiparous people, high-risk pregnancies, multiple gestations, deliveries at less than 39 weeks gestation, and elective cesarean deliveries. Univariate and multivariate analysis was performed.

RESULTS

A total of 174 patients were included. Of these patients, 56 (32.2%) underwent elective induction of labour between 39⁰ and 39⁶ weeks gestation over the period of June 2020 to December 2021, whereas 118 (67.8%) were expectantly managed from 39⁰ weeks gestation over the period of September 2018 to March 2020. Compared with expectant management, those in the 39⁺ weeks induction group had a significantly lower risk of cesarean delivery (odds ratio [OR] 0.39; 95% confidence interval [CI] 0.15-0.99), composite adverse maternal outcomes (OR 0.34; 95% CI 0.12-0.97), and composite adverse perinatal outcomes (OR 0.26; 95% CI 0.074-0.92).

CONCLUSION

Our results suggest that elective induction of labour at 39 weeks gestation and over in low-risk nulliparous people is associated with lower risks of cesarean delivery, composite adverse maternal outcomes, and composite adverse perinatal outcomes than expectant management.

Comparison of cesarean section rates between obstetricians preferring labor induction at early versus late gestational age

OBJECTIVE

To compare the cesarean section (CS) rates of obstetricians with a preference of labor induction at early versus late gestational age.

MATERIAL AND METHODS

Medical records of women who were low risk, nulliparous, singleton pregnancy, and >37 weeks and delivered their babies, were reviewed. Obstetricians, who preferred labor induction at<41 weeks, were allocated to the early induction group; and the other obstetricians were allocated to the late induction group.

RESULTS

The late induction group had a higher percentage of labor induction at ≥41 weeks, compared with the early induction group (21% vs. 8%, p = 0.007). The late induction group had a lower CS rate (11.0% vs. 19.1%, p < 0.001). Multivariable Cox proportional hazard model revealed that the early induction group (hazard ratio [HR] = 2.14, p < 0.001), maternal age (HR = 1.04, p = 0.001), premature rupture of membranes (HR = 1.59, p = 0.006), and birth body weight (kg, HR = 2.13, p < 0.001) were independent predictors of CS. In women receiving labor induction (n = 312), birth body weight (kg, HR = 1.72, p = 0.04) was the sole predictor of CS; and there is a trend that the early induction group (HR = 1.54, p = 0.051) has a higher CS rate, compared with the late induction group. However, gestational age at labor induction was not a predictor of CS.

CONCLUSION

In low-risk pregnancies, obstetricians preferring labor induction at early gestational age seem to be associated with a higher CS rate, compared with obstetricians preferring labor induction at late gestational age. Nonetheless, the above finding seems to be associated with physician's factor, instead of gestational age at labor induction.

Parity and gestational age are associated with vaginal microbiota composition in term and late term pregnancies

Background

Vaginal microbiota and its potential contribution to preterm birth is under intense research. However, only few studies have investigated the vaginal microbiota in later stages of pregnancy or at the onset of labour.

Methods

We used 16S rRNA gene amplicon sequencing to analyse cross-sectional vaginal swab samples from 324 Finnish women between 37–42 weeks of gestation, sampled before elective caesarean section, at the onset of spontaneous labour, and in pregnancies lasting ≥41 weeks of gestation. Microbiota data were combined with comprehensive clinical data to identify factors associated with microbiota variation.

Findings

Vaginal microbiota composition associated strongly with advancing gestational age and parity, i.e. presence of previous deliveries. Absence of previous deliveries was a strong predictor of Lactobacillus crispatus dominated vaginal microbiota, and the relative abundance of L. crispatus was higher in late term pregnancies, especially among nulliparous women.

Interpretation

This study identified late term pregnancy and reproductive history as factors underlying high abundance of gynaecological health-associated L. crispatus in pregnant women. Our results suggest that the vaginal microbiota affects or reflects the regulation of the duration of gestation and labour onset, with potentially vast clinical utilities. Further studies are needed to address the causality and the mechanisms on how previous labour, but not pregnancy, affects the vaginal microbiota. Parity and gestational age should be accounted for in future studies on vaginal microbiota and reproductive outcomes.

Funding

This research was supported by EU H2020 programme Sweet Crosstalk ITN (814102), Academy of Finland, State Research Funding, and University of Helsinki.

Early versus Delayed Amniotomy with Immediate Oxytocin After Foley Catheter Cervical Ripening in Nulliparous Labor Induction: A Randomized Trial

OBJECTIVE

To evaluate immediate oxytocin and early amniotomy compared to delayed amniotomy after Foley catheter cervical ripening in nulliparous women on intervention to delivery interval.

METHODS

A randomized trial was conducted from September 2020-March 2021. 140 term nulliparas (70 early amniotomy, 70 delayed amniotomy) with Foley catheter ripened cervices (dilatation ≥3cm achieved), singleton fetus, cephalic presentation with intact membranes and reassuring fetal heart rate tracing were recruited. Women were randomized to immediate titrated intravenous oxytocin infusion and early amniotomy or delayed amniotomy (after 4 hours of oxytocin). Primary outcome was intervention (oxytocin) to delivery interval (hours).

RESULTS

Intervention to delivery intervals(hours) were mean±standard deviation 9.0±3.6 vs.10.6±3.5 hours (mean difference of 1.4 hours), P=0.004 for early vs.delayed amniotomy arms respectively. Birth rate at 6 hours after oxytocin infusion were 19/70(27.1%) vs.8/70(11.4%) RR 2.38(1.11-5.06) NNTb 7(3.5-34.4), P=0.03, Cesarean delivery rate 29/70(41.4%) vs.33/70(47.1%) RR 0.88(0.61-1.28), P=0.50, and maternal satisfaction on birth process were median [interquartile range] 7[7-8] vs.7[7-8], P=0.40 for early vs.delayed amniotomy arms respectively.

CONCLUSION

In term nulliparas with cervices ripened by Foley catheter, immediate oxytocin and early amniotomy compared to a planned 4-hour delay to amniotomy shortens the intervention to delivery interval but did not significantly reduce the Cesarean delivery rate.

Critical Evaluation of Clinical Research in Obstetrics and Gynecology

Within the evolving field of obstetrics and gynecology, providers should possess the ability to effectively and critically evaluate medical literature in order to best adapt and incorporate evidence-based practice. For both clinicians and researchers alike, we provide a systematic approach for reviewing a journal article published in the medical literature. We summarize the various types of study designs, with dedicated attention to observational and experimental studies, and examine sources of bias inherent to these study designs. Finally, we review important considerations when interpreting the validity and significance of the results and conclusions of a research study.

Neighborhood deprivation increases the risk of Post-induction cesarean delivery

OBJECTIVE

The purpose of this study was to measure the association between neighborhood deprivation and cesarean delivery following labor induction among people delivering at term (≥37 weeks of gestation).

MATERIALS AND METHODS

We conducted a retrospective cohort study of people ≥37 weeks of gestation, with a live, singleton gestation, who underwent labor induction from 2010 to 2017 at Penn Medicine. We excluded people with a prior cesarean delivery and those with missing geocoding information. Our primary exposure was a nationally validated Area Deprivation Index with scores ranging from 1 to 100 (least to most deprived). We used a generalized linear mixed model to calculate the odds of postinduction cesarean delivery among people in 4 equally-spaced levels of neighborhood deprivation. We also conducted a sensitivity analysis with residential mobility.

RESULTS

Our cohort contained 8672 people receiving an induction at Penn Medicine. After adjustment for confounders, we found that people living in the most deprived neighborhoods were at a 29% increased risk of post-induction cesarean delivery (adjusted odds ratio = 1.29, 95% confidence interval, 1.05-1.57) compared to the least deprived. In a sensitivity analysis, including residential mobility seemed to magnify the effect sizes of the association between neighborhood deprivation and postinduction cesarean delivery, but this information was only available for a subset of people.

CONCLUSIONS

People living in neighborhoods with higher deprivation had higher odds of postinduction cesarean delivery compared to people living in less deprived neighborhoods. This work represents an important first step in understanding the impact of disadvantaged neighborhoods on adverse delivery outcomes.

Application of pelvic floor ultrasound during pregnancy to detect patients at risk of cesarean section due to failure of labor progression in a Spanish population

OBJECTIVE

Our study is aimed at evaluating the characteristics of the pelvic floor, assessed through transperineal ultrasound, since it may influence or increase the possibility of having a cesarean delivery, with the objective of acting on those variables that can be modified during pregnancy.

STUDY DESIGN

Transperineal ultrasound was performed on 109 primiparous pregnant women in their first trimester of pregnancy, recruited between May 2018 and February 2019, with the purpose of studying the hiatus area at rest, retention and Valsalva. We have reassessed them at the end of pregnancy and delivery data were recorded. We selected 8 patients as case-study, who had cesarean section delivery due to failure of labor progression. We selected 4 control-cases for each, reaching the total of 32 controls, with similar age and body mass index, to avoid obtaining a biased result from these data.

RESULTS

In the study of hiatal areas, patients who delivered by cesarean section had a smaller hiatal area at rest, during levator ani muscle contraction and during Valsalva maneuver, at all visits. In early pregnancy, the range of the resting hiatal area was 13.8 ± 2.0 cm² for cesarean sections, compared to 16.2 ± 2.7 cm² for vaginal deliveries with an OR of 0.57 (0.34-0.95, 95% CI). For hiatal area on Valsalva, the OR was 0.55 (0.35-0.88, 95% CI). Therefore, the smaller the hiatal area, the greater the possibility of cesarean section. At the end of pregnancy, between 34 and 36 weeks of gestation, the OR of hiatal area on Valsalva was 0.78 (0.60-1.00, 95% CI).

CONCLUSION

The hiatus area measured by transperineal ultrasonography at the beginning and at the end of the pregnancy may be useful to identify the patients who are at a higher risk of cesarean delivery due to failure of labor progression.

Labour induction in twin pregnancies

Medically-indicated deliveries are common in twin pregnancies given the increased risk of various obstetric complications in twin compared to singleton pregnancies, mainly hypertensive disorders of pregnancy and foetal growth restriction. Due to the unique characteristics of twin pregnancies, the success rates and safety of labour induction may be different than in singleton pregnancies. However, while there are abundant data regarding induction of labour in singleton pregnancies, the efficacy and safety of labour induction in twin pregnancies have been far less studied. In the current manuscript we summarize available data on various aspects of labour induction in twin pregnancies including incidence, success rate, prognostic factors, safety and methods for labour induction in twins. This information may assist healthcare providers in counselling patients with twin pregnancies when labour induction is indicated.

Low-dose oxytocin as an adjunct to Foley catheter for cervical ripening in nulliparous women at MTRH, Eldoret, Kenya: A randomized controlled trial

OBJECTIVE

To investigate whether the addition of oxytocin to cervical ripening with a Foley catheter (FC) among nulliparous women shortens the time to delivery.

METHODS

In this double-blinded randomized trial conducted at Moi Teaching and Referral Hospital, 220 women were randomly assigned to FC plus low-dose oxytocin as treatment or FC plus placebo as controls in a 1:1 ratio. A modified intention-to-treat analysis was performed using SPSS v24. The protocol was approved by the institutional ethics committee and registered at www.ctr.pharmacyboardkenya.org; ECCT/19/08/02.

RESULTS

Baseline characteristics were similar. Time to delivery was shorter by 3 h in the treatment group compared with the controls (25.4 versus 28.4 h, P = 0.002). The treatment group had a 22% increased likelihood of delivery within 24 h compared with the controls (53.3% versus 43.1%, relative risk [RR] 1.22, 95% confidence interval [CI] 0.938-1.579, P = 0.135). The controls were however twice more likely to deliver by cesarean section than the treatment group (39% versus 21%, RR 2.32, 95% CI 1.16-2.73, P = 0.006). There were no significant differences in neonatal or other maternal outcomes.

CONCLUSION

FC with adjunctive oxytocin for cervical ripening in nulliparous women results in a shorter time to delivery and reduced cesarean deliveries when compared with FC alone.

Elective labor induction vs expectant management of pregnant women at term and children's educational outcomes at 8 years of age

OBJECTIVE

To estimate the effect of elective induction of labor at 39 weeks' gestation on children's educational outcomes as measured using the Australian National Assessment Program-Literacy and Numeracy (NAPLAN) tests in school year 3 (∼8 years of age), compared with expectant management.

METHODS

We merged perinatal data on all infants born in South Australia from 1999 to 2008 with children's school assessment data from NAPLAN. The study population included all singleton infants born without a malformation at 39-42 weeks in vertex presentation. Children who had undertaken the NAPLAN test in school year 3 were included. We excluded births to women who had a contraindication to vaginal delivery and those with a condition possibly justifying elective delivery before 39 weeks. The outcome of interest was children's educational outcome as measured using NAPLAN, which includes five learning domains (reading, writing, spelling, grammar and numeracy). Each domain was categorized according to performance at or below vs above the national minimum standard (NMS). Average treatment effects (ATEs) of elective induction of labor at 39 weeks compared with expectant management on the proportion of children performing at/below the NMS for each domain were estimated using the augmented inverse-propensity-weighted estimator, accounting for potential confounders.

RESULTS

Of 53 843 children born at 39-42 weeks in vertex presentation from 1999 to 2008 and who were expected to participate in the year-3 NAPLAN from 2008 to 2015, a total of 31 120 had at least one year-3 NAPLAN domain. Of these, 1353 children were delivered after elective induction of labor at 39 weeks while 29 767 children were born following expectant management. The ATEs (mean differences) of elective induction of labor at 39 weeks compared with expectant management on the proportion of children scoring at/below the NMS on each domain were 0.01 (95% CI, -0.02 to 0.03) for reading, 0.02 (95% CI, 0.00-0.04) for writing, 0.01 (95% CI, -0.01 to 0.04) for spelling, 0.02 (95% CI, -0.01 to 0.04) for grammar and 0.03 (95% CI, 0.00-0.05) for numeracy.

CONCLUSION

Elective induction of labor at 39 weeks did not affect children's standardized literacy and numeracy testing outcomes at 8 years of age when compared with expectant management. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Predicting factors of failed induction of labor in three hospitals of Southwest Ethiopia: a cross-sectional study

Introduction

Failed induction of labor affects maternal and neonatal outcomes as well as the cost of healthcare, especially in low-resource setting regions in which the prevalence of failed induction is higher despite the incidence of labor induction is low. This study aimed to assess the prevalence of failed induction of labor in southwest Ethiopia.

Method

A hospital-based cross-sectional study was conducted among 441 induced women from March 1 to August 30, 2018. A systematic random sampling technique was used to select study participants. Data were collected using a pretested and structured questionnaire. Bivariable and multivariable logistic regression models were done and fitted to identify predictors of failed induction. An adjusted odds ratio with 95% confidence interval (CI) was calculated to determine the level of significance.

Result

Premature rupture of membrane was the most common cause of labor induction and the commonly used method of labor induction were oxytocin infusion. Cesarean section was done for 28.1% of induced women. Failed induction of labor was found to be 21%. Primiparous [AOR = 2.35 (1.35–4.09)], analgesia/anesthesia [AOR = 4.37 (1.31–14.59)], poor Bishop Score [AOR = 2.37 (1.16–4.84)], Birth weight ≥ 4 k grams [AOR = 2.12 (1.05–4.28)] and body mass index [AOR = 5.71 (3.26–10.01)] were found to be significantly associated with failed induction of labor.

Conclusion

The prevalence of failed induction of labour was found to be high. Preparation of the cervix before induction in primi-parity women is suggested to improve the success of induction. To achieve the normal weight of women and newborns, proper nutritional interventions should be given for women of reproductive age. It is better to use analgesia/anesthesia for labor induction when it becomes mandatory and there are no other optional methods of no- pharmacologic pain management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03862-x.

Intracervical double-balloon catheter versus dinoprostone for cervical ripening in labor induction in pregnancies with a high risk of uterine hyperstimulation

PURPOSE

There are numerous methods for cervical ripening although not all of them are indicated in women presenting a higher risk of uterine hyperstimulation. To compare the efficacy and security of the two methods for cervical ripening in the induction of labor in these pregnancies.

METHODS

Retrospective analysis of two cohorts consisting of pregnant women who gave birth from 2016 to 2019 (112 inductions with dinoprostone and 112 with intracervical double- balloon).

RESULTS

There are statistically significant differences in favor of dinoprostone in deliveries that occurred before 12 h since the start of the induction (28.6% vs 13.4%, p = 0.005) and a higher rate of cervical ripening (55.4% vs 33.9%; p = 0.001). There were no statistically significant differences in induction time, the percentage of women delivering within 24 h or beyond, nor in the type of delivery. Additionally, a decreased need of oxytocin (60.7% vs 42.9%; p = 0.001) and a lower dose when used has been observed in the dinoprostone group. However, Dinoprostone also has a higher rate of minor maternal complications as uterine hyperstimulation (18.8% vs 3.6%; p = 0.001) and altered cardiotocography (26.8% vs 4.5%; p = 0.001). No significant difference has been found between the two groups regarding severe complications.

CONCLUSIONS

Dinoprostone presents a greater efficacy for cervical ripening and delivery in ≤ 12 h, with less need of oxytocin perfusion than inductions using an intracervical double-balloon. There is no significant difference in severe maternal complications between the two groups. In conclusion, Dinoprostone could be an effective and safe option for patients at risk of uterine hyperstimulation.

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.

Hospital-Level Variation in the Frequency of Cesarean Delivery Among Nulliparous Women Who Undergo Labor Induction

OBJECTIVE

To evaluate the use of administrative data for identification of labor induction and to estimate the variation in cesarean delivery rates among low-risk women who underwent labor induction.

METHODS

A cross-sectional study was performed examining live births in California hospitals during 2016 and 2017 using birth certificate data linked with maternal patient discharge records. Initially, eight hospitals performed medical record reviews by using reVITALize definitions on 46,916 deliveries to assess the validity of induction identification by birth certificate or discharge diagnosis records or both. Hospital-level variation in cesarean delivery rates was then assessed among all California hospitals for women with low-obstetric-risk first births before and after further risk adjustment and after the exclusion of potential medical and obstetric indications for induction. Variation in physician-level cesarean delivery rates after induction at four large hospitals also was examined. The relationships between cesarean delivery rates among women with induced labors compared with noninduced labors and with the hospital rate of induction also were explored.

RESULTS

Identifying induction by a combination of discharge diagnosis codes and birth certificate data had the highest accuracy (92.9%, 95% CI 92.7-93.2). Among 917,225 births at 238 birthing hospitals, there were 99,441 nulliparous women with term, singleton, vertex pregnancies who were induced. The median cesarean delivery rate after labor induction for nulliparous women with term, singleton, vertex pregnancies was 32.2%, with a range of 18.5-84.6%. This wide variation was not reduced after risk adjustment or after exclusion of all women with induction indications. A similar wide variation was noted within geographic regions, neonatal intensive care levels, and among individual physicians in the same facility. Only very weak associations were found for the cesarean delivery rate after labor induction and either the rate after noninduced labor (R<0.08) or the rate of nulliparous labor induction (R<0.12).

CONCLUSION

The large variation of cesarean delivery rates after induction of labor suggests that clinical management plays an important role in achieving induction success.

Disruption of physiological labour; - A population register-based study among nulliparous women at term

OBJECTIVES

Current labour practices have seen an acceleration in interventions to either initiate, monitor, accelerate, or terminate the physiological process of pregnancy and childbirth. This study aimed to describe and analyse the use of interventions in childbirth in Denmark over almost two decades (2000-2017). We also examined the extent to which contemporary care adheres to current international recommendations towards restricted use of interventions.

STUDY DESIGN

A national retrospective Danish register-based cohort study including all nulliparous women with term births with singleton pregnancy and a foetus in cephalic between the years 2000 and 2017 (n = 380,326 births). Multivariate regression analyses with adjustment for change in population were performed.

MAIN OUTCOME MEASURES

Induction of labour, epidural analgesia, and augmentation of labour.

RESULTS

Between 2000/2001 and 2016/2017, the prevalence increased for induction of labour from 5.1% to 22.8%, AOR 4.84, 95% CI [4.61-5.10], epidural analgesia from 10.5% to 34.3% (AOR 4.10, 95% CI [3.95-4.26]), and augmentation of labour decreased slightly from 40.1% to 39.3% (AOR 0.84, 95% CI [0.81-0.86]). Having more than one of the three mentioned interventions increased from 12.8% in to 30.9%.

CONCLUSIONS

The number of interventions increased during the study period as well as the number of interventions in each woman. As interventions may interfere in physiological labour and carry the risk of potential short- and long-term consequences, the findings call for a careful re-evaluation of contemporary maternity care with a "first, do no harm" perspective.

Maternal Morbidity and Birth Satisfaction After Implementation of a Validated Calculator to Predict Cesarean Delivery During Labor Induction

IMPORTANCE

A previously created and validated calculator provides an individualized cesarean delivery risk score for women undergoing labor induction. A higher predicted risk of cesarean delivery on the calculator has been associated with increased maternal and neonatal morbidity regardless of ultimate delivery mode. The effect of this calculator when implemented in clinical care has yet to be evaluated.

OBJECTIVE

To determine whether implementation of a validated calculator that predicts the likelihood of cesarean delivery at the time of labor induction is associated with maternal morbidity and birth satisfaction.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study used medical record review to compare the 1 year before calculator implementation (July 1, 2017, to June 30, 2018) with the 1 year after implementation (July 1, 2018, to June 30, 2019) at a US urban, university labor unit. Women admitted for labor induction with singleton gestation in cephalic presentation, intact membranes, and an unfavorable cervix were included. Data were analyzed from August 1, 2019, to September 13, 2020.

EXPOSURES

Patient and clinician knowledge of the calculated cesarean delivery risk score based on the validated calculator.

MAIN OUTCOMES AND MEASURES

The primary outcomes were (1) composite maternal morbidity defined by at least 1 of the following within 30 days of delivery: endometritis, postpartum hemorrhage (estimated or quantitative blood loss >1000 mL), blood transfusion, wound infection, venous thromboembolism, hysterectomy, intensive care unit admission, and readmission and (2) patient satisfaction assessed via Birth Satisfaction Scale-Revised (BSS-R) scores. Secondary outcomes included rate of cesarean delivery and neonatal morbidity.

RESULTS

A total of 1610 women were included in the analysis (788 in the preimplementation and 822 in the postimplementation periods) with a median age of 29 (interquartile range [IQR], 24-34) years. There were no significant baseline differences between groups except fewer inductions at a gestational age of 40 weeks or later in the postimplementation period (256 [31.1%] vs 298 [37.8%]). Calculator implementation was associated with decreased maternal morbidity overall, even when adjusting for confounders (141 [17.9%] vs 95 [11.6%]; adjusted absolute risk difference [aARD], -6.3%; 95% CI, -9.7% to -2.8%). Although there was no difference in birth satisfaction overall, calculator implementation was associated with improvements on items pertaining to quality of care provision (median BSS-R score, 19 [IQR, 16-20] vs 19 [IQR, 17-20]; P = .006). Calculator implementation was also associated with a decrease in cesarean delivery rate (228 [28.9%] vs 167 [20.3%]; aARD, -8.5% [95% CI, -12.6% to -4.5%]). There were no significant differences in neonatal morbidity.

CONCLUSIONS AND RELEVANCE

These findings suggest that implementation of a validated calculator to predict risk of cesarean delivery in clinical care is associated with reduced maternal morbidity. Implementation should occur broadly to determine whether calculator use improves national maternal outcomes.

Explanatory variables and nomogram of a clinical prediction model to estimate the risk of caesarean section after term induction

The aims of this study were to identify the explanatory variables associated with failure of induction of labour (IOL) and to designate nomograms that predict probability. This retrospective study included 1328 singleton term pregnant women (37-42 weeks). The penalised maximum likelihood estimation (PMLE) method was used instead of traditional logistic regression. Of the 25,678 deliveries that occurred during the study period, 1328 (5.1%) women underwent term delivery. Of those, 1125 (84.7%) had successful vaginal deliveries and 203 (15.3%) had failed vaginal deliveries following use of a dinoprostone slow-release vaginal insert. Explanatory variables were discovered that were associated with delivery failure in term pregnancy undergoing induction of labour with an unfavourable cervix, and a nomogram that predicted probability was developed.IMPACT STATEMENTWhat is already known on this subject? The caesarean rate has continued to climb worldwide over the past decade. Most caesarean sections are performed because of suspected foetal distress or failure to progress. In absolute numbers, most caesarean deliveries are performed in women with a term pregnancy with a foetus in cephalic presentation. Despite these numbers, predicting the mode of delivery by which these women will deliver remains a challenge.What do the results of this study add? Five explanatory variables were strongly associated with failure of dinoprostone delivery of term pregnancies: nulliparity, induction time, premature rupture of membranes, Bishop score and foetal genderWhat are the implications of these findings for clinical practice and further research? The developed nomograms enable fast and easy implementation in clinical practice. After external validation and proof of generalisability, the present model could be used in obstetric clinical management.

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.

Delivery at 39 Weeks of Gestation: The Time Has Come

It has long been observed that neonates born between 39 and 40 gestational weeks have the best perinatal outcomes. What has not been known, until recently, is whether these ideal perinatal outcomes would be achieved in neonates whose delivery was brought on intentionally in this window by labor induction. Recent randomized trials and large observational cohorts have answered this question: labor induction, as compared with expectant management, lowers the rate of cesarean delivery (without increasing other adverse maternal outcomes) and improves perinatal outcomes. For those women still pregnant, delivery at 39 weeks of gestation would simultaneously lower the number of cesarean deliveries and reduce the number of stillbirths and neonatal deaths in the United States.

Association of abnormal first stage of labor duration and maternal and neonatal morbidity

BACKGROUND

Contemporary guidelines for labor management do not characterize abnormal labor on the basis of maternal and/or neonatal morbidity.

OBJECTIVE

In this study, we aimed to evaluate the association of abnormal duration of the first stage of term labor and the risk of maternal and neonatal morbidity.

STUDY DESIGN

We conducted a retrospective analysis of prospectively collected data of all consecutive women admitted for delivery at a single center at ≥37 weeks and 0 to 7 days of gestation with singleton, nonanomalous, vertex infants from 2010 to 2015, who reached 10 cm cervical dilation. Multivariable logistic regression compared odds ratios for maternal and neonatal outcomes among women above and below the 90th, 95th, and 97th percentiles for first stage of labor duration. Receiver operating characteristic curves estimated the association between first stage of labor duration and maternal morbidity. Maternal morbidity was a composite of maternal fever, hemorrhage, transfusion, or endomyometritis; prolonged second stage of labor duration; and third- or fourth-degree perineal laceration. Neonatal morbidity was a composite of hypothermic therapy, need for mechanical ventilation, respiratory distress syndrome, meconium aspiration syndrome, birth injury or trauma, and neonatal seizure or sepsis.

RESULTS

Of 6823 women included in this study, 682 were anticipated to have first stage of labor duration above the 90th percentile cutoff point, which was associated with an increased risk of composite maternal morbidity, maternal fever, postpartum transfusion, prolonged second stage of labor duration, third- or fourth-degree perineal laceration, and cesarean or operative vaginal delivery (P≤.02) and an increased risk of composite neonatal morbidity, respiratory distress syndrome, need for mechanical ventilation, and neonatal sepsis (P≤.03). Composite maternal morbidity was 2.2 (95% confidence interval, 1.8-2.7), 1.9 (95% confidence interval, 1.4-2.4), and 1.8 (95% confidence interval, 1.3-2.5) times more likely to occur among women above the 90th, 95th, and 97th percentile, respectively, for first stage of labor duration from 4 to 10 cm. Composite neonatal morbidity was 2.6 (95% confidence interval, 2.1-3.2), 2.2 (95% confidence interval, 1.7-2.9), and 1.9 (95% confidence interval, 1.3-2.8) times more likely to occur among infants delivered by women above the 90th, 95th, and 97th percentiles for first stage of labor duration from 4 to 10 cm. Receiver operating characteristic curves among all women from 4 to 10 cm and 6 to 10 cm, including when stratified by parity and type of labor onset, had an area under the curve of 0.51 to 0.62 and 0.53 to 0.71 for maternal and neonatal morbidity, respectively. Thus, duration of labor has moderate predictive ability, at best, for composite maternal or neonatal morbidity. No curve demonstrated a clear point at which adverse maternal or neonatal outcomes increased that could be used to define abnormal labor.

CONCLUSION

The benefit of expectantly managing a prolonged first stage of labor with duration above the 90th percentile in anticipation of vaginal delivery must be weighed against the increased risk of composite maternal and neonatal morbidity. Risks associated with performing cesarean delivery as an alternative management for women with prolonged first stage of labor duration must also be considered.

Predicting labor induction success by cervical funneling in uncomplicated pregnancies

Aim

Predictive accuracy of cervical funneling for successful vaginal delivery prior to labor induction was compared to that of conventional methods such as Bishop score and cervical length.

Methods

Prospective observational study was conducted on nulliparous women at 38 gestational weeks or more with intact membranes who delivered vaginally following labor induction. Transvaginal ultrasound was performed prior to labor induction to evaluate the cervix, to determine the cervical length and to check for the presence of funneling. Following pelvic examinations, the Bishop score was calculated. Predictive accuracy of the three different methods, namely cervical funneling, cervical length and Bishop, were compared.

Results

A total of 235 nulliparous women with intact membranes were recruited. Of these, 194 women (82.6%) had successful vaginal deliveries following induction. Cervical funneling was observed in 105 women (44.7%). The rate of successful vaginal delivery was significantly higher in women with cervical funneling than in those without funneling (90.5% vs 76.2%, P < 0.004). Multivariable analysis showed that cervical funneling, similar to traditional measures such as the Bishop score and cervical length, was an independent predictor of successful vaginal delivery following labor induction (odds ratio = 2.95; 95% confidence interval: 1.38–6.47; P = 0.007).

Conclusions

Similar to the conventional methods of cervical evaluation, such as the Bishop score and cervical length, cervical funneling may serve as a useful and valid predictor of successful vaginal deliveries prior to labor induction.

[Evolution of the cesarean delivery rate from 37 weeks of gestation among nulliparas or how to evaluate the external validity of a randomized North American trial about induction of labor]

OBJECTIVE

To determine the risk of caesarean delivery (CD) when an expectant management is considered for a nulliparous reaching≥37 weeks of gestation (wog).

METHODS

This is a prospective study, including all nulliparous women who delivered at≥37 wog a singleton fetus in a cephalic presentation between the first January 2017 and the 31st December 2017 in a French perinatal network (Mypa). For each week of gestation from 37 wog to 41 wog, the rate of CD was determined according the onset of labor (spontaneous or induced). The risk of CD when expectant management was considered at a specific gestational age was calculated by taking all the population who reached this gestational age, minus all women who had an induction of labor or underwent a caesarean delivery before labor.

RESULTS

In total, 16,085 women delivered at≥24 wog, and 5498 (34.1%) were nulliparous with a singleton fetus in a cephalic presentation reaching 37SA. The risk of CD increased from 40 wog, whatever the labor was spontaneous or induced (when labor was spontaneous, the risk of CD was stable till 39 wog around 11%, and increased from 14% at 40 wog to 20% at 41 wog; similarly, when labor was induced, the risk of CD was stable till 39 wog around 28%, and increased from 40% at 40 wog to 38% at 41 wog. The risk of CD for a nulliparous reaching>37 Wog when expectant management is considered was stable around 22.3%.

CONCLUSION

The risk of CD for a nulliparous reaching≥37SA when expectant management is considered is similar than the one in the United States of America.

Effect of early amniotomy on labor outcome in nulliparous women: a randomized clinical trial

Early amniotomy is one of the main interventions to enhance the labor progress and prevent dystocia in pregnant women. However, the efficacy of amniotomy has not been approved via labor-related indices and outcomes and has remained a subject for debate and future research. The present study was conducted to evaluate the effect of early amniotomy on labor indices and outcomes in nulliparous women. This randomized clinical trial was performed on 151 singleton pregnant women who were referred to Besat Hospital in Sanandaj, Iran, from March 2016 to March 2018. Participants were randomly divided into an early amniotomy (EA) group and a control group. Duration of the first and second phases of labor, corioamionit, dystocia rate, Apgar score at the first and fifth minutes, prolonged labor and post-partum haemorrhage were evaluated and compared between the two groups. Data were recorded in a checklist and analysed using SPSS Version 23. The p value <0.05 was considered significant. Results showed that labor indices such as duration of the first and second phases, Apgar score one and five minutes after delivery and frequency of prolonged labor, foetal distress and postpartum haemorrhage were significantly improved in patients of the early amniotomy group, compared with the control group (p≤0.05). Early amniotomy significantly decreased the total labor duration without significant increase in the rate of maternal and neonatal complications.

Development and Validation of a Risk Prediction Model for Cesarean Delivery After Labor Induction

Objective: The goal of the study was to develop and validate a prediction model for cesarean delivery after labor induction that included factors known before the start of induction, unlike prior studies that focused on characteristics at the time of induction. Materials and Methods: Using 17,370 term labor inductions without documented medical indications occurring at 14 U.S. hospitals, 2007-2012, we created and evaluated a model predicting cesarean delivery. We assessed model calibration and discrimination, and we used bootstrapping for internal validation. We externally validated the model by using 2122 labor inductions from a hospital not included in the development cohort. Results: The model contained eight variables-gestational age, maternal race, parity, maternal age, obesity, fibroids, excessive fetal growth, and history of herpes-and was well calibrated with good risk stratification at the extremes of predicted probability. The model had an area under the curve (AUC) for the receiver operating characteristic curve of 0.82 (95% confidence interval 0.81-0.83), and it performed well on internal validation. The AUC in the external validation cohort was 0.82. Conclusion: This prediction model can help providers estimate a woman's risk of cesarean delivery when planning a labor induction.

Elective induction of labor at 39 weeks compared with expectant management: a meta-analysis of cohort studies

BACKGROUND

Elective induction of labor at 39 weeks among low-risk nulliparous women has reduced the chance of cesarean and other adverse maternal and perinatal outcomes in a randomized trial, although its clinical effectiveness in nonresearch settings remains uncertain.

OBJECTIVE

To perform a systematic review of observational studies that compared elective induction of labor at 39 weeks among nulliparous women with expectant management and to use meta-analytic techniques to estimate the association of elective induction with cesarean delivery, as well as other maternal and perinatal outcomes.

STUDY DESIGN

Studies were eligible for this meta-analysis only if they: (1) were observational; (2) compared women undergoing labor induction at 39 weeks with women undergoing expectant management beyond that gestational age; (3) included women in the induction group only if they had no other indication for labor induction at 39 weeks; and (4) provided data specifically for nulliparous women. The predefined primary outcome was cesarean delivery, and secondary outcomes representing other maternal and perinatal morbidities also were evaluated. Outcome data from different studies were combined to estimate pooled relative risks with 95% confidence intervals using random-effects models.

RESULTS

Of 375 studies identified by the initial search, 6 cohort studies, which included 66,019 women undergoing elective labor induction at 39 weeks and 584,390 undergoing expectant management, met inclusion criteria. Elective induction of labor at 39 weeks was associated with a significantly lower frequency of cesarean delivery (26.4% vs 29.1%; relative risk, 0.83; 95% confidence interval, 0.74-0.93), as well as of peripartum infection (2.8% vs 5.2%; relative risk, 0.53; 95% confidence interval, 0.39-0.72). Neonates of women in the induction group were less likely to have respiratory morbidity (0.7% vs 1.5%; relative risk, 0.71; 95% confidence interval, 0.59-0.85); meconium aspiration syndrome (0.7% vs 3.0%; relative risk, 0.49; 95% confidence interval, 0.26-0.92); and neonatal intensive care unit admission (3.5% vs 5.5%; relative risk, 0.80; 95% confidence interval, 0.72-0.88). There also was a lower risk of perinatal mortality (0.04% vs 0.2%; relative risk, 0.27; 95% confidence interval, 0.09-0.76).

CONCLUSION

This meta-analysis of 6 cohort studies demonstrates that elective induction of labor at 39 weeks, compared with expectant management beyond that gestational age, was associated with a significantly lower risk of cesarean delivery, maternal peripartum infection, and perinatal adverse outcomes, including respiratory morbidity, intensive care unit admission, and mortality.

Postdates induction with an unfavorable cervix and risk of cesarean. J Matern Fetal Neonatal Med 2019;32:2874-2878. [PMID: 29562794 PMCID: PMC6636843 DOI: 10.1080/14767058.2018.1450861]

Objective: To determine the risk of cesarean delivery associated with postdates induction (≥41 weeks) compared to term induction (37-40w6d) among women with an unfavorable cervix, and to examine the risk factors associated with cesarean among women undergoing postdates induction. Methods: A planned secondary analysis of a large prospective cohort study on induction (n = 854) was performed. Women with a singleton gestation, intact membranes, and an unfavorable cervix (Bishop score of ≤6 and dilation ≤2 cm) who were undergoing a term (≥37 weeks) induction for any indication were included. Women with a prior cesarean were excluded. The primary outcome was cesarean delivery. Relative risk of cesarean was estimated using a modified Poisson's regression model. Results: There was a significantly increased risk of cesarean for women undergoing postdates induction (n = 154) compared to women 37-40w6d (n = 700), (46.8 versus 26.0%, p < .001). This increased risk of cesarean remained after adjustment for race, parity, and pregnancy-related hypertension (aRR 1.70 [1.39-2.09], p < .001). Risk factors independently associated with cesarean among women ≥41 weeks included nulliparity (aRR 3.38 95%CI (2.42-4.74)), BMI ≥30 (aRR 1.72 95%CI (1.34-2.21)), and starting cervical dilation <1 cm (aRR 1.37 95%CI (1.11-1.70)). Conclusions: Women ≥41 weeks undergoing an induction with an unfavorable cervix are at a significantly increased risk of cesarean compared to women 37-40w6d, with nulliparity, obesity, and cervical dilation <1 cm being independent risk factors. These data can be used to augment patient counseling and support the ongoing discussion regarding the risk of post dates induction.

The ARRIVE Trial: Interpretation from an Epidemiologic Perspective

The findings of the ARRIVE trial (A Randomized Trial of Induction Versus Expectant Management) were recently published. This multisite randomized trial was designed to provide evidence regarding whether labor induction or expectant management is associated with increased adverse perinatal outcomes and risk of cesarean birth among healthy nulliparous women at term. The trial reported that the primary outcome, a composite of adverse neonatal outcomes, was not significantly different between the 2 groups; the principal secondary outcome, cesarean birth, was significantly more common among women whose pregnancy was expectantly managed than among women whose labor was induced at 39 weeks. These results have the potential to change existing practice. Several aspects of the study design may influence its potential internal and external validity and should be considered in order to make sound causal inferences from this trial, which will in turn affect how its findings are translated to practice. Although chance and confounding are of minimal concern, given the sample size and randomization used in the study, selection bias may be a concern. Studies are vulnerable to selection bias when the sample population differs from eligible nonparticipants, including in randomized controlled trials. External validity is defined as the extent to which the study population and setting are representative of the larger source population the study intends to represent. External validity may be limited given the characteristics of the women enrolled in the ARRIVE trial and the practice settings where the study was conducted. This brief report provides concrete suggestions for further analyses that could help solidify conclusions from the trial, and for further research questions that will continue advancement toward answering this complex question of how best to manage labor and birth decisions at full term among low-risk women.

SMFM Statement on Elective Induction of Labor in Low-Risk Nulliparous Women at Term: the ARRIVE Trial

A Randomized Trial of Induction Versus Expectant Management (ARRIVE) was conducted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network from March 2014 to August 2017.This large multicenter, unmasked, randomized controlled trial was performed to test the hypothesis that elective IOL at 39 weeks of gestation, compared with expectant management among low-risk nulliparous women, reduces the risk of a composite outcome of perinatal death or severe neonatal morbidity. Nulliparous women with reliable dating and no obstetric or medical complications were eligible, regardless of favorability of cervical examination. The purpose of this document is to review the findings of the recent randomized trial and to provide guidance for implementation of the study findings.

Using the Probability of Cesarean from a Validated Cesarean Prediction Calculator to Predict Labor Length and Morbidity

OBJECTIVE

To determine if increasing predicted risk of cesarean was associated with longer labor length and increased morbidity among women undergoing induction with an unfavorable cervix.

STUDY DESIGN

Using a publically available database, we evaluated whether a previously validated prediction model for cesarean delivery after induction was associated with labor length, maternal morbidity (third-/fourth-degree lacerations, endometritis, blood transfusion, wound infection, venous thromboembolism, hysterectomy, intensive care unit admission, and death), and neonatal morbidity (blood transfusion, encephalopathy, intraventricular hemorrhage, severe respiratory distress syndrome, necrotizing enterocolitis, and sepsis). Full-term (≥37 weeks) singleton gestations with intact membranes and an unfavorable cervix (Bishop score ≤6 and dilation ≤2 cm) undergoing induction of labor were included.

RESULTS

A total of 8,466 women met the inclusion criteria. Each category increase in cesarean probability (<20, 20-39.9, 40-59.9, ≥60%) was associated with an increase in labor length (9.6, 10.8, 11.7, and 11.9 hours, respectively; p < 0.001). With increasing predicted probability of cesarean there, was also a significant increase in maternal morbidity with each category (2.6, 4.7, 5.1, 6.1%; p = 0.001) and increase in neonatal morbidity (0.9, 1.5, 2, 2.2%; p = 0.002).

CONCLUSION

Using a validated prediction model for cesarean delivery among women induced with an unfavorable cervix, increasing predicted probability of cesarean is associated with longer labor length and increased maternal and neonatal morbidity.

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.

Impact of different glycaemic treatment targets on pregnancy outcomes in gestational diabetes

AIM

With no current randomized trials, we explored the impact of tight compared with standard treatment targets on pregnancy outcomes in gestational diabetes mellitus (GDM).

METHODS

This cohort study of singleton births ≥ 28 weeks' gestation was conducted at two major Australian maternity services (2009-2013). Standardized maternal, neonatal and birth outcomes were examined using routine healthcare data and compared for women with GDM at Service One (n = 2885) and Service Two (n = 1887). Services applied different treatment targets: Service One (standard targets, reference group) fasting < 5.5 mmol/l, 2-h postprandial < 7.0 mmol/l; Service Two (tight targets) fasting < 5.0 mmol/l, 2-h postprandial < 6.7 mmol/l. Multivariable regression with propensity score adjustment was used to examine associations between targets and outcomes.

RESULTS

GDM prevalence and insulin use were 7.9% and 31% at Service One, and 5.7% and 46% at Service Two. There were no differences in primary outcomes: birthweight > 90th centile [adjusted odds ratio (OR) 1.06, 95% confidence interval (CI) 0.87-1.30] and < 10th centile (OR 0.84, 95% CI 0.70-1.01), or secondary outcomes gestational hypertension, pre-eclampsia, shoulder dystocia or a perinatal composite. Service Two with tight targets had increased induction of labour (OR 3.63, 95% CI 3.17-4.16), elective Caesarean section (OR 1.75, 95% CI 1.37-2.23) and Apgar scores < 7 at 5 min (OR 1.54, 95% CI 1.05-2.25), decreased hypoglycaemia (OR 0.76, 95% CI 0.61-0.94]), jaundice (OR 0.47, 95% CI 0.35-0.63) and respiratory distress (OR 0.68, 95% CI 0.47-0.98).

CONCLUSIONS

Tight GDM treatment targets were associated with greater insulin use and no difference in primary birthweight outcomes. The service with tight targets had higher obstetric intervention, lower rates of reported hypoglycaemia, jaundice, respiratory distress and lower Apgar scores. High-quality interventional data are required before tight treatment targets can be implemented.

Pregnancy outcomes of elective induction in low-risk term pregnancies: A propensity-score analysis

We investigated the mode of delivery and perinatal outcomes in low-risk pregnant women whose labor was electively induced or expectantly managed at term.Healthy women with viable, vertex singleton pregnancies at 37 to 40 weeks of gestation were included. Women electively induced (n = 416) in each week (37-37, 38-38, 39-39, 40-40 weeks) were compared with pregnant women with spontaneous labor (n = 487). The primary outcome was mode of delivery. A propensity score (PS) was derived using logistic regression to model the probability of elective induction group as a function of potential confounders. Altogether, 284 women with elective induction were matched with 284 women who underwent expectant management to create a PS-matched population. All analysis was performed using SAS software, version 9.4 (SAS Institute Inc., Cary, NC). All P values reported of the significance level was set at <.05.There are no significant differences of delivery mode, neonatal intensive care unit (NICU) admission, and neonatal complication between PS-matched groups. Incidence of antepartum complications showed higher in the elective induction group compared to the spontaneous labor group (P = .04). When comparing each gestational week, incidence of NICU admission at 38 weeks in the elective induction group [10/74 (13.5%)] was significantly higher than in and the spontaneous labor group [2/74 (2.7%)] (P = .04).Elective induction of labor at term is not associated with increased risk of cesarean delivery. However, overall incidence of NICU admission at 38 gestational weeks seems to be increased in elective induction.

Elective induction of labor: A prospective observational study

The aim of the present study was to assess indications for induction and describe the characteristics and delivery outcome in medical compared to non-medical/elective inductions. During a three-month period, 1663 term inductions were registered in 24 delivery units in Norway. Inclusion criteria were singleton pregnancies with cephalic presentation at gestational age 37⁺⁰ and beyond. Indications, pre-induction Bishop scores, mode of delivery and adverse maternal and fetal outcomes were registered, and compared between the medically indicated and elective induction groups. Ten percent of the inductions were elective, and the four most common indications were maternal request (35%), a previous negative delivery experience or difficult obstetric history (19%), maternal fatigue/tiredness (17%) and anxiety (15%). Nearly half of these inductions were performed at 39⁺⁰–40⁺⁶ weeks. There were fewer nulliparous women in the elective compared to the medically indicated induction group, 16% vs. 52% (p<0.05). The cesarean section rate in the elective induction group was 14% and 17% in the medically indicated group (14% vs. 17%, OR = 0.8, 95% CI 0.5–1.3). We found that one in ten inductions in Norway is performed without a strict medical indication and 86% of these inductions resulted in vaginal delivery.

Benefits and risks of induction of labor at 39 or more weeks in uncomplicated nulliparous women: a retrospective, observational study

Objective

To critically compare the benefits and risks of labor induction versus spontaneous labor in uncomplicated nulliparous women at 39 or more weeks of gestation.

Methods

We conducted a retrospective, observational study of 237 nulliparous women who were at 39 or more weeks of a singleton pregnancy with vertex presentation and intact membranes. We compared maternal outcomes including the Cesarean section rate and neonatal outcomes in the induced labor and spontaneous labor groups.

Results

Among the 237 women, 199 delivered vaginally (84.0%). The spontaneous labor group and induced labor group had a similar incidence of Cesarean delivery (17.7% vs. 12.3%, P=0.300). The length of stay and blood loss during delivery were also similar between the groups (4.3±1.5 vs. 3.9±1.5 days and 1.9±1.3 vs. 1.8±1.0 mg/sL, respectively; all P>0.05). Regarding neonatal outcomes, the rate of meconium-stained amniotic fluid, Apgar score <7 at 5 minutes, and intubation rate were similar between the groups (18.9% vs. 24.7%, 7.9% vs. 4.1%, and 6.1% vs. 4.4%, respectively, all P>0.05). Only the neonatal intensive care unit admission rate was significantly lower in the induction group than in the spontaneous labor group (28.0% vs. 13.2%, P=0.001).

Conclusion

Maternal adverse outcomes of labor induction at 39 weeks of gestation were similar to those in a spontaneous labor group in uncomplicated nulliparous women. Neonatal adverse events were also similar between the groups. It may be acceptable to schedule labor induction as long as 7 days before the estimated date, even when the indication is only relative.

Predictors of cesarean delivery in cervical ripening and labor induction with Foley catheter

Purpose: The aim of this paper is to identify predictors of cesarean delivery (CD) in patients with an unfavorable cervix undergoing cervical ripening and labor induction with Foley catheter.Materials and methods: A retrospective cohort study of singleton pregnancies induced using Foley catheter was performed to evaluate whether factors in the maternal history and during the process of labor induction are useful in predicting the risk of CD.Results: During the study period there were 2221 births in the Chair and Department of Obstetrics and Perinatology, Medical University of Lublin, Poland. From a cohort of 402 women with Foley catheter induction (FCI), 327 met inclusion criteria. There were 236 vaginal labors (72.2%) and 91 CDs (27.8%). Nulliparity (OR 2.344), Bishop score of 1-2 points (OR 1.473), and meconium-stained amniotic fluid (OR 1.980) are linked to the risk of CD. In nulliparous patients, factors associated with an increased risk of CD included maternal age greater than 30 years (OR 3.200), meconium-stained amniotic fluid (OR 2.505), and birthweight ≥3400 g (OR 1.803). Among multiparous women none of the evaluated factors was significantly connected to CD.Conclusions: Nulliparity, low Bishop score, and meconium-stained amniotic fluid are important risk factors of CD after FCI.

Elective induction of labor at 39 weeks among nulliparous women: The impact on maternal and neonatal risk

Objective

Optimal management of pregnancies at 39 weeks gestational age is unknown. Therefore, we sought to perform a comparative effectiveness analysis of elective induction of labor (eIOL) at 39 weeks among nulliparous women with non-anomalous singleton, vertex fetuses as compared to expectant management (EM) which included IOL for medical or obstetric indications or at 41 weeks in undelivered mothers.

Materials and methods

A Monte Carlo micro-simulation model was constructed modeling two mutually exclusive health states: eIOL at 39 weeks, or EM with IOL for standard medical or obstetrical indications or at 41 weeks if undelivered. Health state distribution probabilities included maternal and perinatal outcomes and were informed by a review of the literature and data derived from the Consortium of Safe Labor. Analyses investigating preferences for maternal versus infant health were performed using weighted utilities. Primary outcome was determining which management strategy posed less maternal and neonatal risk. Secondary outcomes were rates of cesarean deliveries, maternal morbidity and mortality, stillbirth, neonatal morbidity and mortality, and preferences regarding the importance of maternal and perinatal health.

Results

A management strategy of eIOL at 39 weeks resulted in less maternal and neonatal risk as compared to EM with IOL at 41 weeks among undelivered patients. Cesarean section rates were higher in the EM arm (35.9% versus 13.9%, p<0.01). When analysis was performed only on patients with an unfavorable cervix, 39 week eIOL still resulted in fewer cesarean deliveries as compared to EM (8.0% versus 26.1%, p<0.01). There was no statistical difference in maternal mortality (eIOL 0% versus EM 0.01%, p = 0.32) but there was an increase in maternal morbidity among the EM arm (21.2% versus 16.5, p<0.01). There were more stillbirths (0.13% versus 0%, p<0.0003), neonatal deaths (0.25% versus 0.12%, p< 0.03), and neonatal morbidity (12.1% versus 9.4%, p<0.01) in the EM arm as compared to the eIOL arm. Preference modeling revealed that 39 week eIOL was favored over EM.

Conclusions and relevance

Mathematical modeling revealed that eIOL at 39 weeks resulted in lower population risks as compared to EM with induction of labor at 41 weeks. Specifically, eIOL at 39 weeks resulted in a lower cesarean section rate, lower rates of maternal morbidity, fewer stillbirths and neonatal deaths, and lower rates of neonatal morbidity.

[To the question of elective induction of labor at 39 weeks of gestation, the answer lies in the question]

The goal of induction of labor is to achieve vaginal delivery when the benefits of expeditious delivery outweigh the risks of continuing the pregnancy. In order to correctly understand the problematic of the elective induction of labor at 39 weeks of gestation (WG), two questions must be raised. (i) What is the perinatal mortality evolution according the gestational age at delivery? All the most recent and methodologically well-conducted studies are convergent: they show that the fetal mortality risk exceeds the perinatal/infant (during the first year of life) mortality risk from 39 WG. The benefit/risk balance related to the expectant management is therefore reversed from 39 WG in favor of the elective induction of labor when the considered issue is the perinatal mortality. (ii) What are the associated risks with elective induction of labor? While some observational studies suggested that the elective induction of labor after 37 WG was associated with an increased risk of cesarean sections, these studies presented a major methodological bias: an error in the control group selection. Indeed, the control group consisted of women in spontaneous labor, whereas the appropriate comparison group must be an expectant management group. Several large cohort studies using a rigorous methodology have shown that elective induction of labor at 39 WG reduces the cesarean section risk compared to an expectant management. Three systematic reviews with meta-analysis of randomized controlled trials comparing induction of labor with expectant management were published: two showed that the cesarean section risk was lowered with the induction of labor compared to an expectant management and the third that the cesarean section rates were similar. Finally, the most recent randomized controlled trial, published in 2016, showed no significant difference between the 2 arms in the cesarean section rate. In all, the most recent literature data, free from comparative bias, show that elective induction of labor at term is associated with a significant reduction in the cesarean section risk and perinatal morbidity and mortality compared to an expectant management.