Induction of labor in the absence of standard medical indications: incidence and correlates

Indications of Induction and Caesarean Sections Performed Using the Robson Classification in a University Hospital in Spain from 2010 to 2021

Background: The Robson Ten Group Classification System (RTGCS) enables the assessment, monitoring, and comparison of caesarean section rates both within healthcare facilities and between them, and the indications of caesarean sections (CS) performed in a maternity ward. The aims of the present study were to conduct an analysis to assess the levels and distribution of birth from a descriptive approach by CS in La Ribera University Hospital (Spain) between 2010-2021 using the Robson classification; to describe the indications for the induction of labour and the causes of caesarean sections performed; and to examine the association between the induction of labour and CS birth. Methods: A retrospective study between 1 January 2010 and 31 December 2021. All eligible women were classified according to the RTGCS to determine the absolute and relative contribution by each group to the overall CS rate. The odds ratio (OR) of the variables of interest was estimated by logistic regression. In an analysis of the subgroups, the level of significance was adjusted using the Bonferroni method. Results: 20,578 women gave birth during the study period, 19% of them by CS. In 33% of births, induction was performed, and the most common cause was the premature rupture of membranes. Group 2 (nulliparous with induced labour/elective CS before labour) accounted for the largest contribution to the overall rate of CS (31.5%) and showed an upward trend from 23.2% to 39.7% in the time series, increasing the CS rate by 6.7%. The leading cause of CS was suspected fetal distress, followed by induction failure. Conclusions: In our study, Robson Group 2 was identified as the main contributor to the hospital's overall CS rate. Determining the causes of induction and CS in a population sample classified using the RTGCS enables the identification of the groups with the greatest deviation from the optimal rate of CS and the establishment of improvement plans to reduce the overall rate of caesarean sections in the maternity unit.

Guideline No. 432a: Cervical Ripening and Induction of Labour - General Information

OBJECTIVE

This guideline presents evidence and recommendations for cervical ripening and induction of labour. It aims to provide information to birth attendants and pregnant individuals on optimal perinatal care while avoiding unnecessary obstetrical intervention.

TARGET POPULATION

All pregnant patients.

BENEFITS, HARMS, AND COSTS

Consistent interprofessional use of the guideline, appropriate equipment, and trained professional staff enhance safe intrapartum care. Pregnant individuals and their support person(s) should be informed of the benefits and risks of induction of labour.

EVIDENCE

Literature published to March 2022 was reviewed. PubMed, CINAHL, and the Cochrane Library were used to search for systematic reviews, randomized controlled trials, and observational studies on cervical ripening and induction of labour. Grey (unpublished) literature was identified by searching the websites of health technology assessment and health technology related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

All providers of obstetrical care.

RECOMMANDATIONS

Directive clinique no 432a : Maturation cervicale et déclenchement artificiel du travail - Information générale

OBJECTIF

Présenter des données probantes et des recommandations sur la maturation cervicale et le déclenchement artificiel du travail. Fournir de l'information aux professionnels accoucheurs et aux personnes enceintes sur les soins périnataux optimaux et la prévention des interventions obstétricales inutiles.

POPULATION CIBLE

Toutes les patientes enceintes. BéNéFICES, RISQUES ET COûTS: La mise en application interprofessionnelle et cohérente de la présente directive, l'équipement adéquat et le personnel compétent améliorent la sécurité des soins per partum. Les personnes enceintes et leurs personnes de soutien doivent être informées des risques et bénéfices du déclenchement artificiel du travail. DONNéES PROBANTES: La littérature publiée jusqu'en mars 2022 a été passée en revue. Une recherche a été effectuée dans les bases de données PubMed, CINAHL et Cochrane Library pour répertorier des revues systématiques, des essais cliniques randomisés et des études observationnelles sur la maturation cervicale et le déclenchement artificiel du travail. La littérature grise (non publiée) a été obtenue à l'aide de recherches menées dans des sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, des registres d'essais cliniques et des sites Web de sociétés de spécialité médicale nationales et internationales. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Tous les fournisseurs de soins obstétricaux.

RECOMMANDATIONS

Validating machine learning models for the prediction of labour induction intervention using routine data: a registry-based retrospective cohort study at a tertiary hospital in northern Tanzania

OBJECTIVES

We aimed at identifying the important variables for labour induction intervention and assessing the predictive performance of machine learning algorithms.

SETTING

We analysed the birth registry data from a referral hospital in northern Tanzania. Since July 2000, every birth at this facility has been recorded in a specific database.

PARTICIPANTS

21 578 deliveries between 2000 and 2015 were included. Deliveries that lacked information regarding the labour induction status were excluded.

PRIMARY OUTCOME

Deliveries involving labour induction intervention.

RESULTS

Parity, maternal age, body mass index, gestational age and birth weight were all found to be important predictors of labour induction. Boosting method demonstrated the best discriminative performance (area under curve, AUC=0.75: 95% CI (0.73 to 0.76)) while logistic regression presented the least (AUC=0.71: 95% CI (0.70 to 0.73)). Random forest and boosting algorithms showed the highest net-benefits as per the decision curve analysis.

CONCLUSION

All of the machine learning algorithms performed well in predicting the likelihood of labour induction intervention. Further optimisation of these classifiers through hyperparameter tuning may result in an improved performance. Extensive research into the performance of other classifier algorithms is warranted.

Effect of maternal age on maternal and perinatal outcomes including cesarean delivery following induction of labor in uncomplicated elderly primigravidae

ABSTRACT

Age above 35 years at the time of birth is generally referred to as advanced maternal age (AMA), and it could be a risk factor for various complications besides genetic changes in the fetus. The primary outcome of this study was to determine if AMA is associated with emergent cesarean delivery (CD) following induction of labor (IOL). The secondary outcomes were a composite of adverse maternal and perinatal outcomes following IOL.This retrospective observational study included women with singleton, live-born, cephalic, non-anomalous pregnancies undergoing IOL from 38 0/7 to 41 6/7 weeks of gestation. Mode of delivery and other maternal and neonatal outcomes were compared between women aged ≥35 (AMA) and <35 years. Multivariate logistic regression analyses were performed.A total of 307 nulliparous women underwent IOL (≥35 years n = 73, 23.8%; <35 years n = 234, 76.2%) and among them, 252 (82.1%) delivered vaginally. The rate of CD was significantly higher in women of AMA (31.5% vs 13.7%, P = .001). Multivariable analysis showed that AMA was independently associated with CD (odds ratio 3.04, 95% confidence interval 1.55-5.96, P = .001). The rate of instrumental deliveries was higher in the AMA group (19.6% vs 8.2%, P = .043) and hemoglobin decrease during delivery was similar between the 2 groups (1.90 ± 1.25 vs 2.02 ± 1.27 mg/dL, all P > .05). Regarding neonatal outcomes, there was no difference between the 2 groups in the neonatal intensive care unit admission rate and Apgar score <7 at 5 minutes (30.3% vs 30.1% and 6.0% vs 8.2%, respectively, all P > .05). Neonatal intubation rate and severe respiratory problems were non-significantly higher in AMA (3.8% vs 2.7% and 3.4% vs 1.4%, respectively, all P > .05).AMA was associated with an approximately three-fold increased likelihood of birth by CD and operative vaginal delivery in uncomplicated nulliparous women following IOL. However, we found no evidence that IOL in primigravid women of AMA increases adverse maternal and perinatal outcomes as compared with women aged <35 years except the high prevalence of CD and operative vaginal delivery.

Examining Cesarean Section Rates in Canada Using the Modified Robson Classification

OBJECTIVE

Canada's cesarean delivery (CD) rate continues to increase. The Society of Obstetricians and Gynaecologists of Canada advocates the use of the modified Robson classification for comparisons. This study describes national and provincial CD rates according to this classification system.

METHODS

All 2016-2017 in-hospital births in Canada (outside Québec) reported to the Discharge Abstract Database were categorized using the modified Robson classification system. CD rates, group size, and contributions of each group to the overall volume of CD were reported. Rates by province and hospital peer group were also examined (Canadian Task Force Classification III).

RESULTS

A total of 286 201 women gave birth; among these, 83 262 (29.1%) had CDs. Robson group 5 (term singleton previous CD) had a CD rate of 80.5% and was the largest contributing group to the overall number of CD (36.6%). Women whose labour was induced (Robson group 2A) had a CD rate almost double the rate of women with spontaneous labour (Robson group 1): 33.5% versus 18.4%. These latter two groups made the next largest contributions to overall CD (15.7% and 14.1%, respectively). There were substantial variations in CD rates across provinces and among hospital peer groups.

CONCLUSION

The study found large variations in CD rates across provinces and hospitals within each Robson group, thus suggesting that examining variations to determine the groups contributing the most to CD rates (Robson groups 5, 2A, and 1) may provide valuable insight for reducing CD rates. This study provides a benchmark for measuring the impact of future initiatives to reduce CD rates in Canada.

Target populations to reduce cesarean rates after induced labor: A national population-based cohort study

INTRODUCTION

Great variations in cesarean rates after induction of labor exist and reasons for these disparities remain unclear. They may be explained by individual characteristics or obstetric practices. Ten-group classification systems have proved their utility to monitor cesarean rates in general population. We aimed to identify groups of women that account for most cesareans after induction of labor using the Nippita reproducible 10-group classification, specifically designed for induced population.

MATERIAL AND METHODS

A prospective population-based cohort study was performed in 94 French maternity units, including 3042 women undergoing induction of labor. Women were sorted according to 10 mutually exclusive groups based on parity, weeks of gestation, number of fetuses, fetal presentation and previous cesarean delivery. Relative size, cesarean delivery rate and contribution to the overall cesarean rate were described for each group. Cesarean rates were compared according to the Bishop score at the onset of labor induction. Indications for cesarean delivery were also described in the groups that contributed most to the overall cesarean rate. The MEDIP protocol was registered in ClinicalTrial (NCT02477085).

RESULTS

The overall cesarean rate was 21.0% among this population of induced women. Nulliparous women with a term singleton cephalic fetus (groups 1, 2 and 3; at 37-38, 39-40 and ≥41 weeks of gestation, respectively) accounted for two-thirds of the overall cesarean rate because they were the largest group (relative size of 10.6, 16.6 and 18.1%, respectively) and had higher cesarean rates (27.2, 30.9 and 33.0%, respectively). When the Bishop score was <6 (n = 2270/3042), cesarean delivery rates were higher (24.1 vs 10.7% if Bishop score ≥6, P < 0.01), in particular for group 1 (29.1 vs 12.5%, P = 0.02), and group 2 (33.3 vs 19.3%, P = 0.01). In groups 1, 2 and 3, which contributed most to the overall cesarean rate, a significant part of the cesareans were performed before 6 cm of cervical dilation for dystocia only (40.0, 16.7 and 17.6%, respectively).

CONCLUSIONS

Nulliparous women with a term singleton cephalic fetus and an unfavorable cervix represent the population to target for auditing induction practices. Specific actions could be implemented among this population to weigh the benefits and risks of induction and improve the management of labor induction.

Clinical factors and ultrasound parameters to predict successful vaginal delivery following labour induction

Morbidity and complications are higher with caesarean delivery after labour induction. We aimed to evaluate which maternal/neonatal pregnancy characteristics and ultrasound parameters are useful in predicting successful vaginal delivery following labour induction. In this retrospective observational study, several maternal and foetal characteristics were studied in 197 primigravidae women at 38 or more gestational weeks before induction. Multivariate analysis showed that maternal age (odds ratio [OR] 0.907, 95% confidence intervals [CI] 0.826-0.995, p = .038), term body mass index (BMI; OR 0.909, 95% CI 0.828-0.997, p = .044), and foetal engagement (OR 3.295, 95% CI 1.232-8.810, p = .017) were independent predictors for a successful vaginal delivery in an induced labour. An older maternal age, high term BMI and un-engagement were associated with a failed labour induction.IMPACT STATEMENTWhat is already known on this subject? Labour induction is being used more frequently worldwide, but it is not always easy to predict those patients who will progress to a vaginal delivery and those who will require a caesarean section. Because caesarean sections are associated with a higher mortality and morbidity in patients who have undergone a labour induction, it is important to identify the factors predictive of successful vaginal delivery after labour induction.What do the results of this study add? Multivariate analysis showed that maternal age, term BMI, and foetal engagement were independent predictors for successful vaginal delivery in an induced labour.What are the implications of these findings for clinical practice and/or further research? We found that maternal age, term body mass index and foetal engagement were important variables to consider when predicting a successful labour induction. A comprehensive assessment of these variables should be done before inducing labour to limit any unnecessary mortality and morbidity associated with a failed induction. Women should be given accurate information regarding the risks of induction based on their individual characteristics.

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.

The Ten-Group Robson Classification: A Single Centre Approach Identifying Strategies to Optimise Caesarean Section Rates

Caesarean section (CS) rates have been increasing worldwide and have caused concerns. For meaningful comparisons to be made World Health Organization recommends the use of the Ten-Group Robson classification as the global standard for assessing CS rates. 2625 women who birthed over a 12-month period were analysed using this classification. Women with previous CS (group 5) comprised 10.9% of the overall 23.5% CS rate. Women with one previous CS who did not attempt VBAC contributed 5.3% of the overall 23.5% CS rate. Second largest contributor was singleton nulliparous women with cephalic presentation at term (5.1% of the total 23.5%). Induction of labour was associated with higher CS rate (groups 1 and 3) (24.5% versus 11.9% and 6.2% versus 2.6%, resp.). For postdates IOL we recommend a gatekeeper booking system to minimise these being performed <41 weeks. We suggest setting up dedicated VBAC clinic to support for women with one previous CS. Furthermore review of definition of failure to progress in labour not only may lower CS rates in groups 1 and 2a but also would reduce the size of group 5 in the future.

Maternal and perinatal outcomes in women with and without hypertensive syndromes submitted to induction of labor with misoprostol

OBJECTIVES

To determine maternal and perinatal outcomes according to the mode of delivery in normotensive and hypertensive women bearing a live, full-term fetus, who were submitted to labor induction with misoprostol.

METHODS

Retrospective cohort study. The endpoints were tachysystole, uterine hyperstimulation, indications for cesarean section, severe maternal morbidity, side effects, maternal death, 1st/5th minute Apgar, neonatal death, requirement for neonatal intensive care, and birth weight (grams). The chi-square or Fisher's exact test was applied at a significance level of 5%. Risk ratios (RRs) and their 95% confidence intervals (95% CI) were calculated.

RESULTS

No significant differences were found in maternal outcome as a function of mode of delivery. First-minute Apgar score <7 was less common with vaginal deliveries in normotensive women (RR = 0.41; 95% CI: 0.18-0.90), this being the only significant difference in perinatal outcome.

CONCLUSION

Maternal and perinatal outcomes were similar in hypertensive and normotensive women submitted to labor induction with misoprostol.

Induced Labor in Sweden, 1999-2012: A Population-Based Cohort Study

BACKGROUND

Previous studies show contradictory results about the impact of induced labor on the cesarean delivery rate and few studies have investigated the risk of vacuum extraction subsequent to induced labor. The aims of the present study were to describe the rate of induced labor in Sweden from 1999 to 2012, and to assess the risk of unplanned cesarean delivery and vacuum extraction after induced labor in relation to medical complications and length of gestation.

METHODS

A register-based cohort study was conducted, including 1,078,536 women with spontaneous or induced onset of labor who gave birth by noninstrumental vaginal delivery, unplanned cesarean delivery, or vacuum extraction in gestational week 37 + 0 to 41 + 6. Logistic regression was used to study the association between induced labor and instrumental delivery.

RESULTS

The rate of induced labor increased from 7.7 to 12.9 percent among primiparous and from 7.5 to 11.8 percent among multiparous women. Induced labor was associated with 2-3 times greater risk of unplanned cesarean delivery among all women, except multiparas in gestational week 37-38, and with a 20-50 percent higher risk of vacuum extraction after the adjustment for confounding factors. Among women without a recognized medical complication, induced labor was associated with a threefold increased risk of cesarean delivery in gestational week 39-41 and a 40 percent increase in gestational week 37-38 compared with women with spontaneous onset of labor.

CONCLUSIONS

The proportion of induced labors increased substantially during the 14-year study period and was associated with an increased risk of both cesarean delivery and vacuum extraction, even in women without a documented medical complication. The increased risk of instrumental delivery should be taken into account when counseling about the risks and benefits of induced labor.

Cesarean section and the manipulation of exact delivery time

Physicians are often alleged responsible for the manipulation of delivery timing. We investigate this issue in a setting that negates the influence of financial incentives on physician's behavior. Working on a sample of women admitted at the onset of labor in a big public hospital in Italy we estimate a model for the exact time of delivery as driven by individual Indication to Cesarean Section (ICS) and covariates. We find that ICS does not affect the day of delivery but leads to a circadian rhythm in the likelihood of delivery. The pattern is consistent with the postponement of high ICS deliveries in the late night\early morning shift. Our evidence hardly supports the manipulation of timing of births as driven by medical staff's "demand for leisure". Physicians seem to manipulate the exact timing of delivery to reduce exposure to risk factors extant during off-peak periods.

Elective induction of labour and maternal request: a national population-based study

OBJECTIVE

To estimate the rate of elective inductions in France and the proportion of them that were maternally requested, and to study the factors associated with elective inductions that were or were not requested by women.

DESIGN

Cross-sectional population-based study.

SETTING

All maternity units in France.

POPULATION

About 14 681 women from the 2010 French National Perinatal Survey of a representative sample of births.

METHODS

Inductions were classified as elective based on their indications and maternal and fetal characteristics, collected from medical records. Elective inductions requested by women were identified from the mother's postpartum interviews. Polytomous logistic regression analysis was used to study the determinants of inductions that were or were not maternally requested. Women with spontaneous labour served as the comparison group.

MAIN OUTCOME MEASURE

Rate of elective inductions.

RESULTS

The induction rate was 22.6, 13.9% elective. Among elective inductions, 47.3% were requested by women. The characteristics of mothers, pregnancies, and maternity units were similar in both groups of elective inductions. The main associated factors were parity 2 or more [adjusted odds ratio (OR) 4.7, 95% confidence interval (CI) 3.1-7.2 for maternally requested inductions and aOR of 1.8 (95% CI1.2-2.7) for unrequested inductions, compared with parity 0] and private hospital status [aOR 4.5 95% (CI 3.3-6.0) for maternally requested inductions and aOR 3.7 (95% CI 2.8-4.9) for inductions not requested by the mother]. We found no association between maternal social characteristics and type of elective induction.

CONCLUSION

Parity and organisational factors appear to influence the decision about elective inductions. It would be interesting to determine how obstetricians and women make this decision and for what reasons.

TWEETABLE ABSTRACT

About 13.9% of inductions of labour were elective in France, 47.3% of these requested by women.

Factors associated with vaginal delivery in hypertensive and normotensive pregnant women submitted to labor induction with misoprostol: a cohort study

OBJECTIVE

To determine the factors associated with vaginal delivery in hypertensive and normotensive pregnant women submitted to induction of labor with misoprostol.

METHODS

A cohort study.

RESULTS

The factors associated with vaginal delivery in both normotensive and hypertensive women were, respectively, Bishop score ≥ 4 (OR = 1.87; 95% CI: 1.06-3.29; p = 0.03) and (OR = 2.31; 95% CI: 1.25-4.28; p = 0.008) and parity ≥ 1 (OR = 4.36; 95% CI: 2.16-8.80; p < 0.0001) and (OR = 2.61; 95% CI: 1.36-5.04; p = 0.004).

CONCLUSION

The factors associated with vaginal delivery were Bishop score ≥ 4 and parity ≥ 1 irrespective of whether or not the women were hypertensive.

Is oxytocin a maternal-foetal signalling molecule at birth? Implications for development

The neuropeptide oxytocin was first noted for its capacity to promote uterine contractions and facilitate delivery in mammals. The study of oxytocin has grown to include awareness that this peptide is a neuromodulator with broad effects throughout the body. Accumulating evidence suggests that oxytocin is a powerful signal to the foetus, helping to prepare the offspring for the extrauterine environment. Concurrently, the use of exogenous oxytocin or other drugs to manipulate labour has become common practice. The use of oxytocin to expedite labour and minimise blood loss improves both infant and maternal survival under some conditions. However, further investigations are needed to assess the developmental consequences of changes in oxytocin, such as those associated with pre-eclampsia or obstetric manipulations associated with birth. This review focuses on the role of endogenous and exogenous oxytocin as a neurochemical signal to the foetal nervous system. We also examine the possible developmental consequences, including those associated with autism spectrum disorder, that arise from exogenous oxytocin supplementation during labour.

Epidemiologic considerations: scope of problem and disparity concerns

Elective labor induction is an increasingly common practice not only in high-income countries but also in many low-income and middle-income countries. Many questions remain unanswered on the safety and cost-effectiveness of elective labor induction, particularly in resource-constrained settings wherein there may be a high unmet need for medically indicated inductions, as well as limited or no access to appropriate medications and equipment for induction and monitoring, comprehensive emergency obstetric care, safe, and timely cesarean section, and appropriate supervision from health professionals. This article considers the global perspective on the epidemiology, practices, safety, and costs associated with elective labor induction.

Induction of labour

OBJECTIVE

To review the most current literature in order to provide evidence-based recommendations to obstetrical care providers on induction of labour.

OPTIONS

Intervention in a pregnancy with induction of labour.

OUTCOMES

Appropriate timing and method of induction, appropriate mode of delivery, and optimal maternal and perinatal outcomes.

EVIDENCE

Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in 2010 using appropriate controlled vocabulary (e.g., labour, induced, labour induction, cervical ripening) and key words (e.g., induce, induction, augmentation). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to the end of 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The evidence in this document was rated using criteria described in the Report of the Canadian Task Force on Preventative Health Care (Table 1). SUMMARY STATEMENTS: 1. Prostaglandins E(2) (cervical and vaginal) are effective agents of cervical ripening and induction of labour for an unfavourable cervix. (I) 2. Intravaginal prostaglandins E(2) are preferred to intracervical prostaglandins E(2) because they results in more timely vaginal deliveries. (I).

An Analysis of the NSW Midwives Data Collection over an 11-Year Period to Determine the Risks to the Mother and the Neonate of Induced Delivery for Non-Obstetric Indication at Term

Objective. To determine the risks of induced term delivery to the mother and neonate at different gestational ages in the absence of obstetric indications. Study Design. All deliveries in New South Wales (NSW) between 1998 and 2008 were reviewed from the MDC. Uncomplicated pregnancies which were induced for non-obstetric reasons after 37 completed weeks were reviewed. This was a retrospective, historical cohort study, and both maternal and neonatal outcomes were analysed and compared between different gestational age groups. Results. An analysis of the data shows that induction of labour after 37 completed weeks exposes the fetus and mother to different levels of risk at different gestations. Conclusion. In an uncomplicated pregnancy, induction of labour is associated with the highest rate of neonatal complication at 37 weeks as compared with rates at later gestations. With each ensuing week, the neonatal outcome improves. At 40 weeks the likelihood of neonatal intensive care admission, low Apgar scores, and perinatal death rate is at its lowest, and then there is a slight but not significant rise after 41 weeks. The likelihood of caesarean section is the lowest when inductions are carried out at 39 weeks and is the highest at 41 weeks and over.

Patterns and Outcomes of Induction of Labour in Africa and Asia: a secondary analysis of the WHO Global Survey on Maternal and Neonatal Health

Background

Labour induction should be performed where benefit outweighs potential harm, however epidemiology of induction in lower-income countries is not well described. We used the WHO Global Survey dataset to describe the epidemiology and outcomes of labour induction in 192,538 deliveries in 253 facilities across 16 countries in Africa and Asia.

Methods

Data was analyzed separately for Africa and Asia. Prevalence of indications, methods, success and characteristics associated with labour induction were determined. Multilevel logistic regression was used to determine the relationship between induction (with medical indication and elective) and maternal/perinatal outcomes.

Results

Induction accounted for 4.4% (Africa) and 12.1% (Asia) of deliveries. Oxytocin alone was the most common method (45.9% and 37.5%) and success rates were generally over 80%. Medically indicated inductions were associated with increased adjusted odds of Apgar <7 at 5 minutes, low birthweight, NICU admission and fresh stillbirth in both regions. The odds of caesarean section in Africa were reduced (Adj OR 0.61, 95%CI 0.42–0.88). Elective induction was associated with increased adjusted odds of NICU (Africa) and ICU (Asia) admissions.

Discussion

Induction was generally less common than in higher-income countries. Prostaglandin use was uncommon despite evidence supporting use. Induction for medical indications may be associated with poorer outcomes due to maternal baseline risks. Despite one-third of elective inductions occurring at <39 weeks, the risk of maternal, fetal and neonatal mortality was not elevated following elective inductions.

Induction of labor and risk of postpartum hemorrhage in low risk parturients

Objective

Labor induction is an increasingly common procedure, even among women at low risk, although evidence to assess its risks remains sparse. Our objective was to assess the association between induction of labor and postpartum hemorrhage (PPH) in low-risk parturients, globally and according to its indications and methods.

Method

Population-based case-control study of low-risk women who gave birth in 106 French maternity units between December 2004 and November 2006, including 4450 women with PPH, 1125 of them severe, and 1744 controls. Indications for labor induction were standard or non-standard, according to national guidelines. Induction methods were oxytocin or prostaglandins. Multilevel multivariable logistic regression modelling was used to test the independent association between induction and PPH, quantified as odds ratios.

Results

After adjustment for all potential confounders, labor induction was associated with a significantly higher risk of PPH (adjusted odds ratio, AOR1.22, 95%CI 1.04–1.42). This excess risk was found for induction with both oxytocin (AOR 1.52, 95%CI 1.19–1.93 for all and 1.57, 95%CI 1.11–2.20 for severe PPH) and prostaglandins (AOR 1.21, 95%CI 0.97–1.51 for all and 1.42, 95%CI 1.04–1.94 for severe PPH). Standard indicated induction was significantly associated with PPH (AOR1.28, 95%CI 1.06–1.55) while no significant association was found for non-standard indicated inductions.

Conclusion

Even in low risk women, induction of labor, regardless of the method used, is associated with a higher risk of PPH than spontaneous labor. However, there was no excess risk of PPH in women who underwent induction of labor for non-standard indications. This raises the hypothesis that the higher risk of PPH associated with labor induction may be limited to unfavorable obstetrical situations.

Induction of labor in a contemporary obstetric cohort

OBJECTIVE

We sought to describe details of labor induction, including precursors and methods, and associated vaginal delivery rates.

STUDY DESIGN

This was a retrospective cohort study of 208,695 electronic medical records from 19 hospitals across the United States, 2002 through 2008.

RESULTS

Induction occurred in 42.9% of nulliparas and 31.8% of multiparas and elective or no recorded indication for induction at term occurred in 35.5% and 44.1%, respectively. Elective induction at term in multiparas was highly successful (vaginal delivery 97%) compared to nulliparas (76.2%). For all precursors, cesarean delivery was more common in nulliparas in the latent compared to active phase of labor. Regardless of method, vaginal delivery rates were higher with a ripe vs unripe cervix, particularly for multiparas (86.6-100%).

CONCLUSION

Induction of labor was a common obstetric intervention. Selecting appropriate candidates and waiting longer for labor to progress into the active phase would make an impact on decreasing the national cesarean delivery rate.

Elective induction versus spontaneous labour in Latin America

OBJECTIVE

To assess the frequency of elective induction of labour and its determinants in selected Latin America countries; quantify success in attaining vaginal delivery, and compare rates of caesarean and adverse maternal and perinatal outcomes after elective induction versus spontaneous labour in low-risk pregnancies.

METHODS

Of 37,444 deliveries in women with low-risk pregnancies, 1847 (4.9%) were electively induced. The factors associated with adverse maternal and perinatal outcomes among cases of spontaneous and induced onset of labour were compared. Odds ratios for factors potentially associated with adverse outcomes were calculated, as were the relative risks of having an adverse maternal or perinatal outcome (both with their 95% confidence intervals). Adjustment using multiple logistic regression models followed these analyses.

FINDINGS

Of 11,077 cases of induced labour, 1847 (16.7%) were elective. Elective inductions occurred in 4.9% of women with low-risk pregnancies (37,444). Oxytocin was the most common method used (83% of cases), either alone or combined with another. Of induced deliveries, 88.2% were vaginal. The most common maternal adverse events were: (i) a higher postpartum need for uterotonic drugs, (ii) a nearly threefold risk of admission to the intensive care unit; (iii) a fivefold risk of postpartum hysterectomy, and (iv) an increased need for anaesthesia/analgesia. Perinatal outcomes were satisfactory except for a 22% higher risk of delayed breastfeeding (i.e. initiation between 1 hour and 7 days postpartum).

CONCLUSION

Caution is mandatory when indicating elective labour induction because the increased risk of maternal and perinatal adverse outcomes is not outweighed by clear benefits.

Rates of labor induction without medical indication are overestimated when derived from birth certificate data

OBJECTIVE

The purpose of this study was to determine the rates of late preterm inductions without a medical indication from birth certificate data and to compare them with rates that were obtained from medical charts.

STUDY DESIGN

The Ohio Perinatal Quality Collaborative, which comprises 20 hospitals in Ohio that came together in 2008 for the purpose of decreasing nonmedically indicated scheduled deliveries, abstracted data on all scheduled births between 36 weeks and 38 weeks 6 days of gestation. We compared labor inductions with "elective" documented or no indication documented in charts to birth certificate data for inductions with no maternal or fetal complications recorded.

RESULTS

Birth certificates overestimate rates of induction without medical indication compared with chart abstraction (11% vs 1%; P < .0001). The monthly difference between chart abstraction and birth certificates averages 10.1%.

CONCLUSION

Birth certificates overestimate nonmedically indicated inductions by 11-fold. Until birth certificate data improve, nonmedically indicated induction rates that are calculated from birth certificates should be interpreted with caution.

Factors and outcomes associated with the induction of labour in Latin America

OBJECTIVE

To describe the prevalence of labour induction, together with its risk factors and outcomes in Latin America.

DESIGN

Analysis of the 2005 WHO global survey database.

SETTING

Eight selected Latin American countries.

POPULATION

All women who gave birth during the study period in 120 participating institutions.

METHODS

Bivariate and multivariate analyses.

MAIN OUTCOME MEASURES

Indications for labour induction per country, success rate per method, risk factors for induction, and maternal and perinatal outcomes.

RESULTS

Of the 97,095 deliveries included in the survey, 11,077 (11.4%) were induced, with 74.2% occurring in public institutions, 20.9% in social security hospitals and 4.9% in private institutions. Induction rates ranged from 5.1% in Peru to 20.1% in Cuba. The main indications were premature rupture of membranes (25.3%) and elective induction (28.9%). The success rate of vaginal delivery was very similar for oxytocin (69.9%) and misoprostol (74.8%), with an overall success rate of 70.4%. Induced labour was more common in women over 35 years of age. Maternal complications included higher rates of perineal laceration, need for uterotonic agents, hysterectomy, ICU admission, hospital stay>7 days and increased need for anaesthetic/analgesic procedures. Some adverse perinatal outcomes were also higher: low 5-minute Apgar score, very low birthweight, admission to neonatal ICU and delayed initiation of breastfeeding.

CONCLUSIONS

In Latin America, labour was induced in slightly more than 10% of deliveries; success rates were high irrespective of the method used. Induced labour is, however, associated with poorer maternal and perinatal outcomes than spontaneous labour.

Provider documentation and elective induction of labor: a 6-month experience at a university medical center

OBJECTIVE

This retrospective study investigated the documentation of clinical history that assured fetal lung maturity, presentation part, and gestational age by 3 provider groups (university obstetricians, family practice, and private obstetricians) before the elective induction of labor.

STUDY DESIGN

This study was conducted at a large university-based medical center. All labor/delivery admissions (n = 1297) and all elective inductions of labor (n = 268) were reviewed. The variables that were compared included provider group vs delivery percentages, induction rates, and cesarean deliveries.

RESULTS

Nine percent of elective inductions occurred before 39 weeks of gestation; 12.7% of the inductions lacked documentation of the presenting part; 17.6% of the inductions failed to meet any commonly accepted screening criteria that assured fetal lung maturity. Rates of elective inductions varied between 16% and 31% when the 3 groups of providers were compared (P < .0001).

CONCLUSION

Adequate documentation is lacking in electively induced patients. A statistically significant relation exists between provider group and clinical behavior as they relate to the elective induction of labor.