Challenges in timing and mode of delivery in morbidly obese women

Globally obesity is increasing especially in the reproductive age group. Pregnant women with obesity have higher complication and intervention rates. They are also at increased risk of stillbirth and intrapartum complications. Although organisations like NICE, RCOG, ACOG and WHO have published guidelines and recommendations on care of pregnant women with obesity the evidence from which Grade A recommendations can be made on timing and how to deliver is limited. The current advice is therefore to have discussions with the woman on risks to help her make an informed decision about timing, place, and mode of delivery. Obesity is an independent risk factor for pregnancy complications including diabetes, hypertension and macrosomia. In those with these complications, the timing of delivery is often influenced by the severity of the complication. As an independent factor, population based observational studies in obese women have shown an increase in the risk of stillbirth. This risk increases linearly with weight from overweight through to class II obesity, but then rises sharply in those with class III obesity by at least 10-fold beyond 42 weeks when compared to normal weight women. This risk of stillbirth is notably higher in obese women from 34 weeks onwards compared to normal weight women. One modifiable risk factor for stillbirth as shown from various cohorts of pregnant women is prolonged pregnancy. Research has linked obesity to prolonged pregnancy. Although the exact mechanism is yet unknown some have linked this to maternal dysregulation of the hypothalamic pituitary adrenal axis leading to hormonal imbalance delaying parturition. For these women the two dilemmas are when and how best to deliver. In this review, we examine the evidence and make recommendations on the timing and mode of delivery in women with obesity. For class I obese women there are no differences in outcome with regards to timing and mode of delivery when compared to lean weight women. However, for class II and III obesity, planned induction or caesarean sections may be associated with a lower perinatal morbidity and mortality although this may be associated with an increased in maternal morbidity especially in class III obesity. Studies have shown that delivery by 39 weeks is associated with lower perinatal mortality compared to delivering after in these women. On balance the evidence would favour planned delivery (induction or caesarean section) before 40 weeks of gestation. In the morbidly obese, apart from the standard lower transverse skin incision for CS, there is evidence that a supraumbilical transverse incision may reduce morbidity but is less cosmetic. Irrespective of the option adopted, it is important to discuss the pros and cons of each.

Failed induction of labor in term nulliparous women with an unfavorable cervix: Comparison of cervical ripening by two forms of vaginal prostaglandins (slow-release pessary and vaginal gel)

OBJECTIVE

To compare the rate of failed induction after cervical ripening by two forms of vaginal prostaglandins.

MATERIAL AND METHODS

This two-year retrospective study (January 1, 2016, through December 31, 2017) in two tertiary maternity units included nulliparous women with a singleton fetus in cephalic presentation and an unfavorable cervix requiring labor induction for prolonged pregnancy. The principal endpoint was the rate of failed induction, defined by the performance of a cesarean delivery before 6 cm of dilation. Cervical ripening was initiated by prostaglandins for 24 h, using a slow-release pessary (unit A) or a vaginal gel (unit B). The care protocol of the two groups after the first 24 h were similar. The women's individual characteristics were compared between the two units. The rates of failed induction were then compared between the two units, first by univariate and then by multivariable analysis adjusted for the characteristics that differed significantly between the units.

RESULTS

Among the 17,217 women delivered in the two maternity units during the study period, 178 met our inclusion criteria (125 in unit A (slow-release pessary) and 53 in unit B (vaginal gel)). The rate of failed induction was similar: 21.6% in unit A (slow-release pessary) and 17.0% in unit B (vaginal gel) (P = 0.48). The multivariate analysis did not show any difference about failed induction, time from the onset of induction to delivery, and vaginal delivery rate within 24h.

CONCLUSION

The rate of failed induction of labor did not differ between slow-release pessary and vaginal gel.

[Prolonged and post-term pregnancies: a regional survey of French clinical practices]

OBJECTIVE

To assess professional practices of prolonged and post-term pregnancies in accordance to French guidelines. The secondary outcome was to evaluate neonatal and maternal morbidity during prolonged pregnancy.

METHODS

Descriptive retrospective study was conducted in the 23 maternity hospitals of perinatal network between September and December 2018. The inclusion criterion was a birth term of≥41⁺⁰ weeks of gestation. Primary outcome was conformity to the national guidelines based on 10 items (conformity score≥80%). The secondary outcome was a composite criteria of neonatal morbidity (ventilation, resuscitation and/or Apgar score<7 at 5minutes) and maternal morbidity (obstetrical anal sphincter injury and/or postpartum hemorrhage).

RESULTS

A total of 596 patients were included and the conformity was obtained in 65.3% of cases. Inconsistent criteria were amniotic fluid evaluation by the deepest vertical pocket (46.8%, n=279), and information of patients on prolonged pregnancy management (14.8%, n=88). Adverse perinatal outcome occurred for 40 newborns (6.0%) with shoulder dystocia (OR=5.2; CI 95%: 1.4-19.7) as a principal risk factor. Maternal morbidity outcome occurred in 70 cases (10.6%) primarily with increase in labour duration (OR=1.1 by hour of labour; CI 95%: 1.02-1.24) and prior caesarian section (OR=4.4; CI 95%: 1.8-11.0).

CONCLUSIONS

Management of prolonged and post-term pregnancies matching with the French national guidelines. Points of improvement are amniotic fluid evaluation at term by a single deepest vertical pocket, and the information about induction of labour at term.

Maternal obesity in prolonged pregnancy: Labor, mode of delivery, maternal and fetal outcomes

INTRODUCTION

Obesity is currently not a medical indication for elective induction of labor although obese patients may not be eligible for expectant management after 41 W G. Few data on labor and complications in this population undergoing prolonged pregnancy are known. The objective of our study was to evaluate labor, mode of delivery, maternal and fetal outcomes in prolonged pregnancy in obese patients compared to normal body mass index (BMI).

MATERIALS AND METHODS

It was a retrospective cohort study in patients who, after prolonged pregnancy gave birth to a single fetus, in cephalic presentation, between the first of January 2002 and December 31, 2018 in the Caen University Hospital Center. Patient's characteristics were compared within each BMI class using uni- and multivariate analysis with regression logistics models.

RESULTS

Overall, 9159 patients were included. Term of birth and spontaneous labor calculated rates were significantly increased in case of obesity (p < 0.001). The adjusted Odds Ratio (ORa) for induced labor in class III obesity was 1.73 [1.13-2.66]. After induction of labor, 83.0 % patients with normal BMI delivered vaginally versus 61.8 % in case of class III obesity (p < 0.001). The ORa for an emergency cesarean was 3.39 [2.04-5.63] and 1.78 [1.06-2.99] for neonatal morbidity in class III obesity.

CONCLUSION

Morbid obese patients do not belong to a low risk patient's group when pregnancy is prolonged. Elective induction in case of morbid obesity may entail less risk than allowing the pregnancy to progress after 41 W G or even 39 W G. Further randomized prospective studies are nevertheless required.

Amniotic fluid and umbilical cord serum erythropoietin in term and prolonged pregnancies

OBJECTIVE

Erythropoietin - a hormone regulating erythropoiesis - is a biomarker of chronic fetal hypoxia. High erythropoietin levels in fetal plasma and amniotic fluid are associated with increased risk of adverse neonatal outcome. Since the risk of perinatal morbidity and mortality is increased in pregnancies beyond 41 gestational weeks, we evaluated erythropoietin levels in amniotic fluid and umbilical cord serum in apparently low-risk term (≥ 37 gestational weeks) and prolonged pregnancies (≥ 41 gestational weeks) with labor induction.

STUDY DESIGN

This prospective cohort study comprised 93 singleton pregnancies at 37⁺⁰-42⁺¹ gestational weeks, of which prolonged pregnancies numbered 63 (67.7%). Amniotic fluid samples were collected at time of labor induction by amniotomy. Umbilical cord blood samples for evaluation of pH, base excess, and umbilical cord serum erythropoietin were collected at birth. Erythropoietin levels were measured by immunochemiluminometric assay. Normal value of amniotic fluid erythropoietin level was defined as ≤ 3 IU/L, and abnormal value as ≥ 27 IU/L. Normal umbilical cord serum erythropoietin was defined as < 40 IU/L. Data on maternal pregnancy and delivery characteristics and short-term neonatal outcomes such as Apgar score were obtained from the hospital charts. Associations were calculated using Spearman's rank correlation coefficient. The Chi-square test, Fisher's exact test and the Mann-Whitney U test were utilized to determine differences in the study groups.

RESULTS

Amniotic fluid erythropoietin levels correlated with gestational age (r = 0.261, p = 0.012) and were higher among prolonged pregnancies as compared to term pregnancies (p = 0.005). There were 78 (83.9%) vaginal deliveries, and among these erythropoietin levels in amniotic fluid correlated with the levels in umbilical cord serum (r = 0.513, p < 0.000). Umbilical cord serum erythropoietin levels correlated with gestational age among vaginal deliveries (r = 0.250, p = 0.027). Erythropoietin levels in amniotic fluid and umbilical cord serum did not correlate with umbilical artery pH or base excess, or other adverse pregnancy outcome.

CONCLUSIONS

In vaginal deliveries erythropoietin levels in amniotic fluid correlated with the levels in umbilical cord serum. Erythropoietin levels correlated with gestational age, probably due to weakening placental function and relative hypoxemia occurring in advanced gestation. However, in this relatively low-risk study population erythropoietin was not related to adverse delivery outcome.

Timing induction of labour at 41 or 42 weeks? A closer look at time frames of comparison: A review

BACKGROUND

Postterm pregnancy is associated with increased perinatal risk. The WHO defines postterm pregnancy as a pregnancy at or beyond 42 weeks + 0 days, though currently labour is induced at 41 weeks in many settings. Guidelines on timing of labour induction are frequently based on the Cochrane systematic review 'Induction of labour for improving birth outcomes for women at or beyond term' in which is concluded that a policy of induction of labour is associated with fewer adverse perinatal outcome and fewer Caesarean sections. However, the included trials differed regarding the timing of induction, ranging from 39 to beyond 42 weeks while the upper limit of expectant management exceeded a gestational age of 42 weeks in most studies.

OBJECTIVE

to evaluate perinatal mortality, meconium aspiration syndrome and Caesarean section rate of trials comparing a policy of elective induction of labour and expectant management according to timeframes of comparison with a focus on studies within the 41-42 weeks' timeframe.

DESIGN

Review.

METHODS

The systematic review of Cochrane was used as a starting point for assessing relevant trials and a search was performed for additional recent trials. We evaluated incidence and causes of perinatal mortality, incidence of meconium aspiration syndrome and Caesarean section according to three time frames of comparison. We pooled estimates and heterogeneity was tested. The quality of the included trials was assessed using the Quality Assessment Tool for Quantative Studies (EPHPP).

FINDINGS

In total 22 trials were included which had all different timeframes of comparison. Only one trial compared induction of labour at 41 weeks + 0-2 days with induction at 42 weeks + 0 days, three other trials compared induction of labour at 41 weeks + 0-6 days with induction at 42 weeks + 0-6 days. In 18 trials the comparison was outside the 41-42 weeks' timeframe: in six trials induction was planned ≤ 40 weeks and in another 12 trials expectant management was beyond 43 weeks. The incidence of potentially gestational age associated perinatal mortality between 41 and 42 weeks was 0/2.444 [0%] (induction) versus 4/2.452 [0.16%] (expectant management), NNT 613; 95%CI 613 - infinite. Two trials in the timeframe of comparison 41-42 weeks were available for evaluation of meconium aspiration syndrome (6/554 (induction) versus 14/554 (expectant management), RR 0.44; 95%CI 0.17-1.16). Three trials in the timeframe 41-42 weeks could be evaluated for Caesarean section, with different inclusion criteria regarding Bishop score. There was no significant difference in the Caesarean section rate 93/629 (induction) versus 106/629 (expectant management), RR 0.88; 95%CI 0.68-1.13.

CONCLUSION

Evidence is lacking for the recommendation to induce labour at 41 weeks instead of 42 weeks for the improvement of perinatal outcome. More studies comparing both timeframes with an adequate sample size are needed to establish the optimal timing of induction of labour in late-term pregnancies.

Management of pregnancy at and beyond 41 completed weeks of gestation in low-risk women: a secondary analysis of two WHO multi-country surveys on maternal and newborn health

BACKGROUND

The World Health Organization (WHO) recommends induction of labour (IOL) for women who have reached 41 completed weeks of pregnancy without spontaneous onset of labour. Many women with prolonged pregnancy and/or their clinicians elect not to induce, and chose either elective caesarean section (ECS) or expectant management (EM). This study intended to assess pregnancy outcomes of IOL, ECS and EM at and beyond 41 completed weeks.

METHODS

This study is a secondary analysis of the WHO Global Survey (WHOGS) and the WHO Multi-country Survey (WHOMCS) conducted in Africa, Asia, Latin America and the Middle East. There were 33,003 women with low risk singleton pregnancies at ≥41 completed weeks from 292 facilities in 21 countries. Multilevel logistic regression model was used to assess associations of different management groups with each pregnancy outcome accounted for hierarchical survey design. The results were presented by adjusted odds ratios (aORs) with 95% confidence intervals (CIs) after adjusting for age, education, marital status, parity, previous caesarean section (CS), birth weight, and facility capacity index score.

RESULTS

The prevalence of prolonged pregnancy at facility setting in WHOGS, WHOMCS and combined databases were 7.9%, 7.5% and 7.7% respectively. Regarding to maternal adverse outcomes, EM was significantly associated with decreased risk of CS rate consistently in both databases i.e. (aOR0.76; 95% CI: 0.66-0.87) in WHOGS, (aOR0.67; 95% CI: 0.59-0.76) in WHOMCS and (aOR0.70; 95% CI: 0.64-0.77) in combined database, compared to IOL. Regarding the adverse perinatal outcomes, ECS was significantly associated with increased risks of neonatal intensive care unit admission (aOR1.76; 95% CI: 1.28-2.42) in WHOMCS and (aOR1.51; 95% CI: 1.19-1.92) in combined database compared to IOL but not significant in WHOGS database.

CONCLUSIONS

Compared to IOL, ECS significantly increased risk of NICU admission while EM was significantly associated with decreased risk of CS. ECS should not be recommended for women at 41 completed weeks of pregnancy. However, the choice between IOL and EM should be cautiously considered since the available evidences are still quite limited.

Does a policy of earlier induction affect labour outcomes in women induced for postmaturity? A retrospective analysis in a tertiary hospital in the North of England

OBJECTIVES

to investigate whether a change in the management of postmature pregnancy to earlier induction affects the length of labour and the induction process. Secondly, to assess the feasibility of the research process to inform a future larger study.

DESIGN

a change in management of postmature pregnancy in an NHS hospital in October 2013, from induction at 42 weeks gestation to induction between 41-42 weeks, provided an opportunity to conduct a retrospective analysis. Pre-existing data from the maternity database and casenotes were collected and primary outcomes analysed using the Mann-Whitney test and the Hodges-Lehman confidence interval for differences in medians.

SETTING

a large city based tertiary referral hospital in the North of England.

PARTICIPANTS

125 women induced before the change in policy were compared with 309 women induced after the change.

MEASUREMENTS

primary outcomes were length of 1st and 2nd stage of labour, overall length of labour, length of induction to established labour and length of induction to birth.

FINDINGS

the median overall length of labour for women induced at 42 weeks was 6.5hours, while for women induced at 41-42 weeks this was 5.2hours. The difference was not statistically significant (p=0.15, 95% CI for median difference -0.27 to 1.93hours) with a small effect size (Pearson's r=-0.08). The median length of induction to birth was 13.6hours for women induced at 42 weeks and 16.5hours for women induced at 41-42 weeks. This difference was also not statistically significant (p=0.14, 95% CI for median difference -7.25 to 1.20hours) with a small effect size (Pearson's r=-0.13).

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

This study demonstrated no statistically significant differences in length of labour and induction following a change in the management of postmature pregnancy to earlier induction. A large study is needed to establish definitively the effects of earlier induction on labour outcomes.

Association between body mass index (BMI) and duration of pregnancy in women referred to Shariati Hospital in Bandar Abbas

INTRODUCTION

Prolonged pregnancy is associated with increased risk of pregnancy complications. The role of body mass index (BMI) is not completely identified in the risk of occurrence of prolonged pregnancy. The aim of this study was to determine the association between BMI and duration of pregnancy in woman referred to the Shariati Maternity Hospital in Bandar Abbas (Hormozgan Province, Iran).

METHODS

This cross-sectional study was carried out on 1100 pregnant women referred to the Shariati Hospital in Bandar Abbas in 2015. Gestational age determined by last menstrual period (LMP) or first-trimester ultra-sonography. The women were divided into two groups of less than 40 weeks of gestation and more than 40 weeks of gestation. The women were divided based on their BMI at the first trimester of pregnancy into four groups, including less than normal, normal, overweight, and excess weight. Data were analyzed using ANOVA, Mann-Whitney test, and chi-square test by SPSS version 16.0.

RESULTS

The average age of mothers studied was 23 ± 4.30 years. Average of gestational age was 39 ± 1.85 weeks. Among the study participants 1020 (92.7%) had term pregnancies, 53 (4.8%) had preterm pregnancies, and 27 (2.5%) had post-term pregnancies. Also among the study participants, 40% had a BMI less than 19.8 kg/m², 45.9% had BMI between 19.8 and 26 kg/m², and 9.8% had BMI between 26.1 and 29 kg/m², and 4.3% had BMI less than 29 kg/m². Mean BMI was 20.95 ± 4.02 for women with gestational age of equal to or less than 40 weeks and 23.34 ± 4.52 for women with gestational age of more than 40 weeks. Duration of pregnancy was significantly higher in women with higher BMI at the first trimester (p<0.00006).

CONCLUSION

High BMI of a mother in the first trimester of pregnancy is associated with prolonged pregnancy and may increase the risk of post-term pregnancy. Women are recommended to reach an ideal weight before pregnancy to decrease the risk of the pregnancy complications.

Earlier induction of labour in post term pregnancies--A historical cohort study

OBJECTIVE

to evaluate a change of guideline for earlier induction of labour in post term pregnancies and its possible impact on selected birth interventions and outcome of the newborn.

DESIGN

a historical cohort study.

SETTINGS

Department of Obstetrics at Aarhus University Hospital in Denmark.

PARTICIPANTS

18,247 women giving birth between 1 January 2009 and 12 December 2012.

METHODS

to compare induction of labour in two consecutive time periods before and after implementation of a new guideline on induction of labour (42 weeks versus 41 weeks plus five days gestational age) in post term pregnancy. t-Test and χ(2) were used to calculate means of gestational age and relative risk (RR) of selected birth and newborn outcomes. Stratification by Mantel-Haenszel-analysis was used to adjust for possible confounders. Robson׳s classification system 'Ten Group Classification System' was used to create comparable groups within the performed analysis.

FINDINGS

a difference in means of three gestational days after implementation of the new guideline on earlier induction of labour was found together with an overall unadjusted decrease in emergency caesarean section rate of 30% (RR 0.70, 95% CI; 0.54-0.91). Stratified analysis on parity showed a reduction in emergency caesarean section but only in nulliparous women (RR 0.78, 95% CI; 0.66-0.92), whereas the analysis in multiparous women showed a non-statistically significant increased risk of emergency caesarean section (RR 1.39, 95% CI; 0.89-2.18). No differences were found in assisted vaginal childbirths and outcome in newborns concerning Apgar score, pH and standard base excess in women induced in 42 weeks versus 41 weeks plus five days gestational age.

CONCLUSION

the findings of this study suggest that earlier induction of labour due to post term pregnancy has a positive influence, but only in nulliparous women, by lowering the risk of emergency caesarean section evidently without increasing the risk on adverse outcome in newborns.