Maternal outcome monitoring: induction of labor versus spontaneous onset of labor—a retrospective data analysis

The role of labor induction in modern obstetrics

A primary goal of obstetrical practice is the optimization of maternal and perinatal health. This goal translates into a seemingly simple assessment with regard to considerations of the timing of delivery: delivery should occur when the benefits are greater than those of continued pregnancy. In the absence of an indication for cesarean delivery, planned delivery is initiated with induction of labor. When medical or obstetrical complications exist, they may guide recommendations regarding the timing of delivery. In the absence of these complications, gestational age also has been used to guide delivery timing, given its association with both maternal and perinatal adverse outcomes. If there is no medical indication, delivery before 39 weeks has been discouraged, given its association with greater chances of adverse perinatal outcomes. Conversely, it has been recommended that delivery occur by 42 weeks of gestation, given the perinatal risks that accrue in the post-term period. Historically, a 39-week induction of labor, particularly for individuals with no previous birth, has not been routinely offered in the absence of medical or obstetrical indications. That approach was based on numerous observational studies that demonstrated an increased risk of cesarean delivery and other adverse outcomes among individuals who underwent labor induction compared to those in spontaneous labor. However, from a management and person-centered-choice perspective, the relevant comparison is between those undergoing planned labor induction at a given time vs those planning to continue pregnancy beyond that time. When individuals have been compared using that rubric-either in observational studies or randomized trials that have been performed in a wide variety of locations and populations- there has not been evidence that induction increases adverse perinatal or maternal outcomes. Conversely, even when the only indication for delivery is the achievement of a full-term gestational age, evidence suggests that multiple different outcomes, including cesarean delivery, hypertensive disorders of pregnancy, neonatal respiratory impairment, and perinatal mortality, are less likely when induction is performed. This information underscores the importance of making the preferences of pregnant individuals for different birth processes and outcomes central to the approach to delivery timing.

Maternal and Neonatal Outcomes of Elective Induction of Labor at 39 or More Weeks: A Prospective, Observational Study

The purpose of our study is to compare the maternal and neonatal outcomes of induction of labor (IOL) versus expectant management at 39 weeks of gestation. We conducted a single-centered, prospective, observational study of nulliparous singleton women at 39 weeks or more. We compared the maternal and perinatal outcomes. Of 408 nulliparous women, 132 women were IOL group and 276 women were expectant management group. IOL and expectant group had similar cesarean delivery rate (18.2% vs. 15.9%, p = 0.570). The delivery time from admission was longer in IOL group (834 ± 527 vs. 717 ± 469 min, p = 0.040). The IOL group was less likely to have Apgar score at 5 min < 7 than in expectant group (0.8% vs. 5.4%, p = 0.023). Multivariate analysis showed that IOL at 39 weeks was not an independent risk factor for cesarean delivery (relative risk 0.64, 95% confidence interval: 0.28−1.45, p = 0.280). Maternal and neonatal adverse outcomes, including cesarean delivery rate, were similar to women in IOL at 39 weeks of gestation compared to expectant management in nulliparous women. IOL at 39 weeks of gestation could be recommended even when the indication of IOL is not definite.

Prediction of spontaneous onset of labor at term (PREDICT study): Research protocol

Background

Recent studies have shown that elective induction of labor versus expectant management after 39 weeks of pregnancy result in lower incidence of perinatal complications, while the proportion of cesarean deliveries remains stable, or even decreases. Still, evidence regarding collateral consequences of the potential increase of induction of labor procedures is still lacking. Also, the results of these studies must be carefully interpreted and thoroughly counter-balanced with women’s thoughts and opinions regarding the active management of the last weeks of pregnancy. Therefore, it may be useful to develop a tool that aids in the decision-making process by differentiating women who will spontaneously go into labor from those who will require induction.

Objective

To develop a predictive model to calculate the probability of spontaneous onset of labor at term.

Methods

We designed a prospective national multicentric observational study including women enrolled at 39 weeks of gestation, carrying singleton pregnancies. After signing an informed consent form, several clinical, ultrasonographic, biophysical and biochemical variables will be collected by trained staff. If delivery has not occurred at 40 weeks of pregnancy, a second visit and evaluation will be performed. Prenatal care will be continued according to current hospital guidelines. Once recruitment is completed, the information gathered will be used to develop a logistic regression-based predictive model of spontaneous onset of labor between 39 and 41 weeks of gestation. A secondary exploration of the data collected at 40 weeks, as well as a survival analysis regarding time-to-delivery outcomes will also be performed. A total sample of 429 participants is needed for the expected number of events.

Conclusion

This study aims to develop a model which may help in the decision-making process during follow-up of the last weeks of pregnancy.

Trial registration

NCT05109247 (clinicaltrials.gov).

Fetomaternal Outcome Among the Pregnant Women Subject to the Induction of Labor

Introduction

Induction of labor (IOL) is characterized by stimulating contractions of the uterus just before the instantaneous onset of labor, with or without amniotomy. According to the recommendation of the World Health Organization (WHO), induction must only be carried out when there is a clear medical need for one and when potential benefits outweigh the expected harm that may be caused by it. The present study was to determine the frequency of fetomaternal outcomes among pregnant women subject to the induction of labor.

Methods

The present prospective cross-sectional study was conducted over a period of one year starting from June 17, 2018, to July 25, 2019, in the Department of Obstetrics and Gynecology Unit III, Civil Hospital Karachi. After institutional ethical committee approval, 302 pregnant women who were subject to induction of labor were enrolled using a non-probability consecutive sampling technique. Outcome variables, i.e., postpartum hemorrhage, mode of delivery, hospital stay more than seven days, birth asphyxia, Apgar score < 7 at five minutes, neonatal jaundice, and low birth weight were noted. IBM Statistical Package for Social Sciences (SPSS) Statistics for Windows, version 21.0 (IBM Corp., Armonk, NY) was used for data analysis.

Results

A total of 302 women with an average age range was 18-45 years with a mean age of 28.5 ± 4.47, body mass index (BMI) 29.83 ± 3.83, and mean gestational age was 37 ± 4.3. Almost 205 (67.9%) of the cases were booked. One hundred and eighty (59.6%) were nulliparas, 57(18.8%) had para-1, 43 (14.4%) had para-2, and 22 (7.14%) had par-3. When fetomaternal outcome among the pregnant women subject to induction of labor was observed, postpartum hemorrhage was observed in 55 (18.21%), hospital stay more than seven days was in 51 (17%), birth asphyxia was in 45 (14.9%), neonatal jaundice was in 53 (17.6%), low birth weight was in 15 (4.96%), Apgar score < 7 was in 48 (16%), 39 (13%) women underwent for C-section and 263 (87%) of the women delivered vaginally.

Conclusion

This study concludes that the induction of labor (IOL) is safe and reliable and less risk of adverse feto-maternal outcome is associated with pregnancies between 37 weeks and 42 weeks of gestation. The evidence regarding IOL prior to 37 weeks and beyond 42 weeks of gestation is inadequate to reach any conclusion.

Effects of induction of labor prior to post-term in low-risk pregnancies: a systematic review

OBJECTIVE

The objective of this review was to identify, assess and synthesize the best available evidence on the effects of induction prior to post-term on the mother and fetus. Maternal and fetal outcomes after routine labor induction in low-risk pregnancies at 41+0 to 41+6 gestational weeks (prior to post-term) were compared to routine labor induction at 42+0 to 42+6 gestational weeks (post-term).

INTRODUCTION

Induction of labor when a pregnancy exceeds 14 days past the estimated due date has long been used as an intervention to prevent adverse fetal and maternal outcomes. Over the last decade, clinical procedures have changed in many countries towards earlier induction. A shift towards earlier inductions may lead to 15-20% more inductions. Given the fact that induction as an intervention can cause harm to both mother and child, it is essential to ensure that the benefits of the change in clinical practice outweigh the harms.

INCLUSION CRITERIA

This review included studies with participants with expected low-risk deliveries, where both fetus and mother were considered healthy at inclusion and with no known risks besides the potential risk of the ongoing pregnancy. Included studies evaluated induction at 41+1-6 gestational weeks compared to 42+1-6 gestational weeks. Randomized control trials (n = 2), quasi-experimental trials (n = 2), and cohort studies (n = 3) were included. The primary outcomes of interest were cesarean section, instrumental vaginal delivery, low Apgar score (≤ 7/5 min.), and low pH (< 7.10). Secondary outcomes included additional indicators of fetal or maternal wellbeing related to prolonged pregnancy or induction.

METHODS

The following information sources were searched for published and unpublished studies: PubMed, CINAHL, Embase, Scopus, Swemed+, POPLINE; Cochrane, TRIP; Current Controlled Trials; Web of Science, and, for gray literature: MedNar; Google Scholar, ProQuest Nursing & Allied Health Source, and guidelines from the Royal College of Obstetricians and Gynaecologists, and American College of Obstetricians and Gynecologists, according to the published protocol. In addition, OpenGrey and guidelines from the National Institute for Health and Care Excellence, World Health Organization, and Society of Obstetricians and Gynaecologists of Canada were sought. Included papers were assessed by all three reviewers independently using the Joanna Briggs Institute System for the Unified Management, Assessment and Review of Information (JBI SUMARI). The standardized data extraction tool from JBI SUMARI was used. Data were pooled in a statistical meta-analysis model using RevMan 5, when the criteria for meta-analysis were met. Non-pooled results were presented separately.

RESULTS

Induction at 41+0-6 gestational weeks compared to 42+0-6 gestational weeks was found to be associated with an increased risk of overall cesarean section (relative risk [RR] = 1.11, 95% confidence interval [CI] 1.09-1.14), cesarean section due to failure to progress (RR = 1.43, 95% CI 1.01-2.01), chorioamnionitis (RR = 1.13, 95% CI 1.05-1.21), labor dystocia (RR = 1.29, 95% CI 1.22-1.37), precipitate labor (RR = 2.75, 95% CI 1.45-5.2), uterine rupture (RR = 1.97, 95% CI 1.54-2.52), pH < 7.10 (RR = 1.9, 95% CI 1.48-2.43), and a decreased risk of oligohydramnios (RR = 0.4, 95% CI 0.24-0.67) and meconium stained amniotic fluid (RR = 0.82, 95% CI 0.75-0.91). Data lacked statistical power to draw conclusions on perinatal death. No differences were seen for postpartum hemorrhage, shoulder dystocia, meconium aspiration, 5-minute Apgar score < 7, or admission to neonatal intensive care unit. A policy of awaiting spontaneous onset of labor until 42+0-6 gestational weeks showed, that approximately 70% went into spontaneous labor.

CONCLUSIONS

Induction prior to post-term was associated with few beneficial outcomes and several adverse outcomes. This draws attention to possible iatrogenic effects affecting large numbers of low-risk women in contemporary maternity care. According to the World Health Organization, expected benefits from a medical intervention must outweigh potential harms. Hence, our results do not support the widespread use of routine induction prior to post-term (41+0-6 gestational weeks).

Roles and mechanisms of TRPC3 and the PLCγ/PKC/CPI-17 signaling pathway in regulating parturition

The aim of the current study was to investigate the role of phospholipase C (PLC)γ/protein kinase C (PKC)/C-kinase-activated protein phosphatase-1 (CPI-17) signaling pathways in uterine smooth muscle during parturition. Samples of uterine tissue were collected from pregnant patients who underwent a caesarean section for preterm delivery, full-term delivery with labor onset, full-term delivery without labor onset, and from a non-pregnant control group undergoing surgery for cervical intraepithelial neoplasia III. Immunohistochemistry, and western blotting were used to assess the association between TRPC3 levels and parturition and the influence of calcium ion channels. In addition, pregnant mice were used to explore the effect of uterine canonical transient receptor potential 3 (TRPC3) expression on the parturition-triggering mechanism and PLCγ/PKC/CPI-17 signaling pathways. Pregnant mouse uterine smooth muscle cells were cultivated, with and without TRPC3 silencing, and the expression levels of PLCγ, PKC and CPI-17, the upstream and downstream factors of the TRPC3 pathway, were measured in pregnant mouse uterine smooth muscle cells, in order to provide a theoretical basis for the prevention and treatment of premature labor. In the preterm and full-term without labor onset patient groups, the TRPC3 gene expression in the mSMCs was significantly overexpressed when compared with the non-pregnant group (P<0.05); however, TRPC3 expression was not elevated in the full-term with labor onset group, exhibiting no significant difference compared with the non-pregnant group (P>0.05). During pregnancy, compared with the non-pregnant controls, Ca_v1.2, Ca_v3.1 and Ca_v3.2 gene expression levels were markedly increased (P<0.05) in mSMCs from the preterm delivery group and the full-term with labor onset group, however were non-significantly increased in the full-term without labor onset group. The level of TRPC3 was highest in the preterm group, while the levels of Ca_v1.2, Ca_v3.1 and Ca_v3.2 were highest in the full-term with labor onset group. In the preterm, LPS-treated preterm and full-term groups, TRPC3, MAPK, ERK1/2, P-ERK, Ca_v3.2, Ca_v3.1 and Ca_v1.2 were all expressed at higher levels than in the unfertilized group. In the LPS-treated preterm group, the levels of TRPC3, MAPK, ERK1/2, P-ERK, Ca_v3.2, Ca_v3.1 and Ca_v1.2 were increased compared with the preterm group. Furthermore, following transfection of small interfering TRPC3 (siTRPC3) into cells, it was demonstrated that the levels of TRPC3, PLCγ, PKC, CPI-17, P-CPI-17, Ca_v1.2, Ca_v3.1 and Ca_v3.2 expression were lower in the LPS siTRPC3 group when compared with that of the LPS-treated untransfected control group.

Temporal trends in fetal mortality at and beyond term and induction of labor in Germany 2005-2012: data from German routine perinatal monitoring

PURPOSE

While a variety of factors may play a role in fetal and neonatal deaths, postmaturity as a cause of stillbirth remains a topic of debate. It still is unclear, whether induction of labor at a particular gestational age may prevent fetal deaths.

METHODS

A multidisciplinary working group was granted access to the most recent set of relevant German routine perinatal data, comprising all 5,291,011 hospital births from 2005 to 2012. We analyzed correlations in rates of induction of labor (IOL), perinatal mortality (in particular stillbirths) at different gestational ages, and fetal morbidity. Correlations were tested with Pearson's product-moment analysis (α = 5 %). All computations were performed with SPSS version 22.

RESULTS

Induction rates rose significantly from 16.5 to 21.9 % (r = 0.98; p < 0.001). There were no significant changes in stillbirth rates (0.28-0.35 per 100 births; r = 0.045; p = 0.806). Stillbirth rates 2009-2012 remained stable in all gestational age groups irrespective of induction. Fetal morbidity (one or more ICD-10 codes) rose significantly during 2005-2012. This was true for both children with (from 33 to 37 %, r = 0.784, p < 0.001) and without (from 25 to 31 %, (r = 0.920, p < 0.001) IOL.

CONCLUSIONS

An increase in IOL at term is not associated with a decline in perinatal mortality. Perinatal morbidity increased with and without induction of labor.

Breast stimulation in low-risk primigravidas at term: does it aid in spontaneous onset of labour and vaginal delivery? A pilot study

Aims. The aim of the study was to elicit the safety and efficacy of breast stimulation as an intervention to prevent postdatism and as an aid in spontaneous onset of labour. Methods. Primigravidas with cephalic presentation, without any high-risk factor, were recruited between 36 to 38 weeks of gestation. 200 patients were recruited and randomized into two groups (n = 100). Breast stimulation was advised to one group but not to the other group. Bishop's scoring was done at 38 weeks and repeated at 39 weeks of gestation. Maternal and fetal outcomes were compared in two groups. Result. Bishop's score changed from 3.12 (±1.01) to 3.9 (±1.08) in control group and from 3.02 (±0.82) to 6.08 (±1.29) in breast stimulation group after one week (P value < 0.0001). The period of gestation at delivery was 39.5 (±2.3) weeks in control group and 39.2 (±2.8) weeks in intervention group (P value: 0.044). There were increased chances of vaginal delivery in intervention group (P value: 0.046). Duration of labor, hyperstimulation, presence of meconium stained liquor, postpartum hemorrhage, and neonatal outcomes were similar in both groups. Conclusion. Breast stimulation in low-risk primigravidas helps in cervical ripening and increases chances of vaginal delivery.

Managing the primary cesarean delivery rate

One third of deliveries in the United States are by cesarean, a rate that far exceeds that recommended by professional organizations and experts. A dominant reason for the high overall cesarean rate is the rising primary cesarean rate. The high primary cesarean rate results from multiple factors, both clinical and nonclinical. This review outlines proposed interventions to lower the primary cesarean rate. We focus on those implementable at a facility level and would likely yield immediate results, including aligning provider incentives for vaginal birth, limiting elective induction of labor, and improving labor management of dystocia and abnormal fetal heart rate tracings.

Labor induction with prostaglandin E2: characteristics of response and prediction of failure

OBJECTIVE

To characterize the response to labor induction with prostaglandin E2 (PGE2) and to identify risk factors for induction failure.

METHODS

A prospective controlled study of women admitted for labor induction with PGE2. Maternal characteristics, Bishop score and sonographic cervical length were documented at admission. The change in cervical characteristics and the emergence of uterine contractions following each application of PGE2 were analyzed.

RESULTS

Of the 88 women who were included in the study, 19 (21.6%) failed to response to PGE2. The following factors were independently associated with induction failure: nulliparity (odds ratio [OR] = 5.9, 95% confidence interval (CI): 1.2-30.2), pre-pregnancy body mass index >25 kg/m2 (OR = 5.4, 95% CI: 1.1-26.5), Bishop score <4 (OR = 2.3, 95% CI: 1.05-14.4), cervical length <25 mm (OR = 0.2, 95% CI: 0.1-0.8) and the development of uterine contractions in response to the first application of PGE2 (OR = 0.4, 95% CI: 0.1-0.93). Overall, most women required only one (60.9%) or two (85.5%) applications of PGE2 to achieve successful induction. The number of applications of PGE2 required to achieve successful induction was related to parity and cervical status at presentation.

CONCLUSIONS

Overall, most women who eventually respond to PGE2 do so following the first two applications of PGE2, and the contribution of subsequent applications is relatively small and related to cervical status at admission.