Labor length among overweight and obese women undergoing induction of labor

An Externally Validated Model to Predict Prolonged Induction of Labor with an Unfavorable Cervix

OBJECTIVE

 To develop and externally validate a prediction model to calculate the likelihood of prolonged induction of labor (induction start to delivery time > 36 hours).

STUDY DESIGN

 This was a retrospective cohort study of all nulliparous women with singleton pregnancies and vertex presentation at term who underwent induction of labor and had a vaginal delivery at a single academic center. Women with contraindications for vaginal delivery were excluded. Analyses were limited to women with unfavorable cervix (both simplified Bishop score [dilation, station, and effacement: range 0-9] <6 and cervical dilation <3 cm). Prolonged induction of labor was defined as the duration of induction (induction start time to delivery) longer than 36 hours. A backward stepwise logistic regression analysis was used to identify the factors associated with prolonged induction of labor by considering maternal characteristics and comorbidities as well as fetal conditions. The final model was validated using an external dataset of the Consortium on Safe Labor after applying the same inclusion and exclusion criteria. We developed a receiver observer characteristic curve with area under the curve (AUC) in validation cohorts.

RESULTS

 Of 2,118 women, 364 (17%) had prolonged induction of labor. Factors associated with prolonged induction of labor included body mass index at admission, hypertension, fetal conditions, and epidural. Factors including younger maternal age, prelabor rupture of membranes, and a more favorable simplified Bishop score were associated with a decreased likelihood of prolonged induction of labor. In the external validation cohort, 4,418 women were analyzed, of whom 188 (4%) had prolonged induction of labor. The AUC of the final model was 0.76 (95% confidence interval: 0.73-0.80) for the external validation cohort. The online calculator was created and is available at: https://medstarapps.org/obstetricriskcalculator.

CONCLUSION

 Our externally validated model was efficient in predicting prolonged induction of labor with an unfavorable cervix.

KEY POINTS

· The number of inductions of labor at 39 weeks' gestation and beyond has been increasing.. · Our model had a good prediction of prolonged induction of labor.. · An online calculator has been created and available..

Association of maternal Body Mass Index and parity on induced labor stages

BACKGROUND

Obesity is a widespread pandemic and obstetric care must adapt to meet the needs of obese pregnant women. Little is known about the impact of Body Mass Index (BMI) on the induction of labor (IOL). Therefore, our objective was to evaluate if the duration of the first and second stages of IOL is affected by maternal BMI in nulliparous and multiparous women.

METHODS

We included singleton pregnancies at term with cephalic presentation whose labor was induced from June 2018 to December 2019. Women were divided into two groups according to pre-pregnancy BMI in normal weight and obese women.

RESULTS

A total of 668 women with IOL were included in the study, among them, 349 had a normal weight and 321 were obese. The first stage of labor was longer in obese multiparous than normal-weight women (normal weight 81.98±71.7 vs. obese 134.3±158.1 min, P=0.000), while the second stage resulted significantly shorter (normal weight 22.2±27.8 vs. obese 14.3±14.2 min, P=0.000). The total time elapsed from IOL beginning and delivery was significantly higher in obese nulliparous (normal weight 10.4±19.7 vs. obese 22.0±26.2 h, P=0.000). Operative vaginal deliveries, emergency cesarean section, and failed IOL resulted to be similar between the groups.

CONCLUSIONS

Obese multiparous women have longer first stages of labor while shorter second stages. The total time for induced obese nulliparous to reach delivery is higher than the normal weight. It might be reasonable to reconsider the partographs according to maternal BMI in case of induced labor for future obstetric practice.

Vaginal Dinoprostone Insert versus Cervical Ripening Balloon for Term Induction of Labor in Obese Nulliparas-A Randomized Controlled Trial

Data regarding the preferred induction method in women with obesity is scarce. The current study was aimed at comparing pharmacological and mechanical induction in this population. This prospective randomized controlled trial was conducted between 2016−2020, in nulliparas with a pre-pregnancy body mass index >30. Inclusion criteria were singleton-term pregnancies, bishop score < 5, and indication for induction. Patients were randomized to induction by a cervical ripening balloon (CRB) or a 10 mg vaginal dinoprostone insert. The primary outcome was delivery rate within 24 h. Secondary outcomes included time to delivery, cesarean section rate, maternal and neonatal outcomes, satisfaction, and anxiety. The study population comprised of 83 women in the CRB group and 81 in the dinoprostone group. There was a significant difference in delivery rates within 24 h and time to delivery between the dinoprostone and CRB groups (45% vs. 71%, p = 0.017 and 49.3 ± 6.8 h vs. 23.5 ± 5.9 h, p = 0.003, respectively). There were no differences in cesarean delivery rates or maternal and neonatal outcomes, though CRB induction was associated with a significantly lower rate of tachysystole. Induction with CRB was accompanied by higher satisfaction and lower anxiety. In summary, CRB induction is associated with shorter time to delivery, higher satisfaction, and lower anxiety compared to PGE2 in women with obesity, without compromising maternal or neonatal outcomes.

Factors associated with delayed onset of active labor following vaginal misoprostol administration among women at Mbarara Regional Referral Hospital, Uganda

OBJECTIVE

To determine the factors associated with delayed onset of active labor following labor induction with vaginal misoprostol.

METHODS

We conducted a prospective cohort study over 6 months at a tertiary hospital in Uganda. We enrolled mothers with pregnancies of at least 28 weeks, who were undergoing labor induction with 50 µg of vaginal misoprostol, administered every 6 hours with a maximum of four doses, and followed them up until onset of active labor. Labor onset was considered delayed if it occurred later than 12 hours after the first dose. Bivariate and multivariate analysis was performed to determine factors associated with delayed onset of active labor.

RESULTS

Of the 88 mothers enrolled, 22.7% (n=20) had delayed onset of active labor. Nulliparity (adjusted relative risk [aRR] 2.34, 95% confidence interval [CI] 1.17-4.68) and gestational age less than 37 weeks (aRR 3.79, 95% CI 1.40-10.23) were associated with delayed onset of active labor following vaginal misoprostol administration whereas higher body mass index (aRR 0.38, 95% CI 0.18-0.79) decreased the risk.

CONCLUSION

Delayed onset of active labor following labor induction remains an important obstetric care challenge. Mothers undergoing labor induction should have their body mass index documented, and nulliparous women and mothers at less than 37 weeks of gestation should have their labor monitored for a longer duration following labor induction.

Contemporary patterns of labor in nulliparous and multiparous women

BACKGROUND

Controversy surrounds the definition of "normal" and "abnormal" labor.

OBJECTIVE

In this study, we used contemporary labor charts to explore labor patterns in large obstetric population (2011-2016).

STUDY DESIGN

Detailed information from electronic medical records of live singleton deliveries at term (≥37 weeks of gestation) was extracted. Cases of elective cesarean deliveries, nonvertex presentation, and cesarean deliveries during the first stage of labor were excluded.

RESULTS

Overall, 35,146 deliveries were included, of whom 15,948 deliveries (45.3%) were of nulliparous women. Median cervical dilation at admission was not significantly different between nulliparous (median, 4 cm; interquartile range, 3-5 cm) and multiparous women (median, 4 cm; interquartile range, 3-6 cm). In all, 99.3% of the women delivered vaginally. For nulliparous women, the median duration of the first stage of labor was 274 minutes (interquartile range, 145-441 minutes; 95th percentile, 747.5 minutes). Likewise, for multiparous women, the corresponding duration was 133 minutes (interquartile range, 56-244 minutes; 95th percentile, 494 minutes). During the latent phase (cervical dilation at admission, ≤4 cm), the time elapsed to the second stage of labor was 120-140 minutes longer in nulliparous women, whereas the gap between the groups decreased dramatically with advanced cervical dilation on admission. Nulliparous and multiparous women appeared to progress at a similar pace during the latent phase; however, after 5 cm, labor accelerated faster in multiparous women. Epidural anesthesia lengthens duration first and second stages of labor in all parities. Partograms according to cervical dilation at presentation are proposed.

CONCLUSION

Cervical dilation rate is relatively constant between nulliparous and multiparous pregnant women during the latent phase. Time interval of the first stage was far slower than previously described, which allowed labor to continue for a longer period during this stage. These findings may reduce the rate of intrapartum iatrogenic interventions.

The effect of maternal body mass index on duration of induced labor

INTRODUCTION

Obese primiparous women with induction of labor are at high risk for a cesarean section. There are contradictory results regarding time in induced labor in relation to maternal body mass index (BMI). It is important to characterize the course of induced labor to prevent unnecessary cesarean section. We aimed to evaluate whether the duration of labor was associated with maternal BMI in primiparous women with induction of labor.

MATERIAL AND METHODS

A national retrospective cohort study, including 15 259 primiparae with a single term pregnancy, admitted for induction of labor from January 2014 to August 2017. Data were obtained from the Swedish Pregnancy Registry. Cox regression analyses were used to illustrate the association between BMI and active labor and between BMI and time from admission until start of active labor.

RESULTS

Duration of active labor was shorter in underweight women and prolonged in women with BMI ≥40 kg/m² compared with women in other BMI classes, illustrated by Cox regression graphs (P < .001). The median durations of active labor in underweight women were 6.1 and 7.4 hours in women with BMI ≥40 kg/m² . The time from admission until start of active labor increased with maternal BMI, illustrated by Cox regression graphs (P < .001) and the median duration increased from 12.9 hours in underweight women to 22.6 hours in women with BMI ≥40 kg/m² . The cesarean section rate in active labor increased significantly with BMI (P < .001) from 7.4% in underweight women to 22.0% in women with BMI ≥40 kg/m² . Obese and normal weight women had similar rates of spontaneous vaginal delivery (69.9% in the total study population).

CONCLUSIONS

The duration of active labor was associated with maternal BMI for underweight women and women with BMI ≥40 kg/m² . Although women with BMI ≥40 kg/m² who reached the active phase of labor had the same chance for a spontaneous vaginal delivery as normal weight women, the duration of active labor and the cesarean section rate were increased. The time from admission until start of active labor increased successively with maternal BMI.

Preventing Cesarean Birth in Women with Obesity: Influence of Unit-Level Midwifery Presence on Use of Cesarean among Women in the Consortium on Safe Labor Data Set

INTRODUCTION

Maternal obesity is associated with slow labor progression and unplanned cesarean birth. Midwives use fewer medical interventions during labor, and the women they care for have lower cesarean birth rates, compared with low-risk, matched groups of women cared for by physicians. The primary aim of this study was to examine associations between midwifery unit-level presence and unplanned cesarean birth in women with different body mass index (BMI) ranges. Unit-level presence of midwives was analyzed as a representation of a unique set of care practices that exist in settings where midwives work.

METHODS

A retrospective cohort study was conducted using Consortium on Safe Labor data from low-risk, healthy women who labored and gave birth in medical centers with (n = 9795) or without (n = 13,398) the unit-level presence of midwives. Regression models were used to evaluate for associations between unit-level midwifery presence and 1) the incidence of unplanned cesarean birth and 2) in-hospital labor durations with stratification by maternal BMI and adjustment for maternal demographic and pregnancy factors.

RESULTS

The odds of unplanned cesarean birth among women who gave birth in centers with midwives were 16% lower than the odds of cesarean birth among similar women at who gave birth at centers without midwives (adjusted odds ratio, 0.84; 95% CI, 0.77-0.93). However, women whose BMI was above 35.00 kg/m2 at labor admission had similar odds of cesarean birth, regardless of unit-level midwifery presence. In-hospital labor duration prior to unplanned cesarean was no different by unit-level midwifery presence in nulliparous women whose BMI was above 35.00 kg/m2 .

DISCUSSION

Although integration of midwives into the caregiving environment of medical centers in the United States was associated with overall decrease in the incidence of cesarean birth, increased maternal BMI nevertheless remained positively associated with these outcomes.

Foley catheter versus cervical double balloon for labor induction: a prospective randomized study

OBJECTIVE

Cervical ripening by mechanical methods enhances labor induction success. We compared Cervical Ripening Double Balloon catheter (CRDB) to Foley catheter.

STUDY DESIGN

This prospective blind study randomized 85 nulliparas and 95 multiparas to labor induction by either Foley catheter or CRDB. Primary outcomes were Bishop score increment, time from catheter withdrawal to delivery, and cesarean section rate.

RESULTS

In multiparas, mean Bishop score increment between pre- and post-catheter was significantly higher in the CRDB catheter than in the Foley group (4.4 ± 1.9 and 3.4 ± 2.0, respectively, p = .02). Mean interval from catheter withdrawal to delivery was shorter in the CRDB catheter (14.6 ± 12.3 and 8.6 ± 5.4) than in the Foley catheter group (22.6 ± 27.2 and 13.9 ± 17.7), in both nulliparas and multiparas (p = .05 and p = .03, respectively). In nulliparas, no statistically significant differences were found in mean Bishop score increment between the two catheters, but cesarean section rate was higher in the Foley group than the CRDB group (46.5% and 20%, respectively, p = .02).

CONCLUSION

Bishop score increment by CRDB catheter is more effective than induction by Foley catheter in multiparas. CRDB catheter is associated with decreased time to delivery in both nulliparas and multiparas and a lower cesarean section rate in nulliparas. ClinicalTrials.gov Identifier: NCT00501033.

A comparison of cervical ripening modalities among overweight and obese nulliparous gravidas

Objective: To determine if differences exist among nulliparous overweight and obese gravidas undergoing cervical ripening employing three different agents (dinoprostone, misoprostol, or cervical catheter).Methods: A retrospective cohort study of nulliparous overweight and obese women who underwent induction of labor at two south-central Pennsylvania hospitals between January 2014 and December 2017. Nulliparous gravidas, ≥37 weeks' gestational age, with singleton pregnancies in the vertex presentation, were included in the study. We employed the following definitions: (1) overweight: BMI 25.0-29.9 kg/m²; (2) class I obesity: BMI 30.0-34.9 kg/m²; (3) class II obesity: BMI 35.0-39.9 kg/m²; and (4) class III obesity: BMI >40.0 kg/m². The primary outcome measure was the mean difference in induction-to-birth time. A subanalysis was performed to assess the effect of BMI on the primary outcome. Secondary outcome measures included mode of delivery, induction-to-second-stage-of-labor time, estimated blood loss, neonatal feeding type, neonatal Apgar scores, and neonatal admission to triage or intensive care unit (ICU) after delivery. A priori power calculation estimated that 156 patients would be needed using the medium effective size. Data analysis was performed using ANOVA for continuous variables and chi-square tests for categorical variables.Results: Among 192 nulliparous overweight and obese gravidas, 70 received dinoprostone, 72 were given misoprostol, and 50 had cervical ripening with cervical catheters. There were no significant differences in mean induction to birth times among overweight and obese women when comparing the three cervical ripening agents (dinoprostone 24.5 ± 15.2 versus misoprostol 28.7 ± 12.3 and catheters 25.1 ± 12.9 hours), (p = .145, 95% CI -8.7 to 0.2 and -5.5 to 4.3, respectively). Overweight nulliparous women had shorter mean induction to birth time (22.9 ± 11.4 versus 29.2 ± 15.8 hours) as compared to class II obese women, (p = .037, 95% CI -12.0 to -0.38). When overweight women were compared to class III obese women, shorter mean induction to birth time (22.9 ± 11.4 versus 30.9 ± 13.9 hours) was also found, (p = .005, 95% CI -13.4 to -2.4).Conclusion: Among nulliparous overweight and obese gravidas, neither dinoprostone, misoprostol, or cervical catheter significantly impacted the induction to birth time. There was a longer induction to birth time for class II and class III obese women when compared to overweight women. Additional studies are warranted to improve cervical ripening in nulliparous overweight and obese women.

Impact of physical activity during pregnancy on obstetric outcomes in obese women

BACKGROUND

Maternal obesity is associated with complications and adverse outcomes during the labor and delivery process. In pregnant women with a healthy body weight, maternal physical activity during pregnancy is associated with better obstetric outcomes; however, the effect of maternal physical activity during pregnancy on obstetric outcomes in obese women is not known. The purpose of the study was to determine the influence of self-reported physical activity levels on obstetric outcomes in pregnant obese women.

METHODS

A retrospective chart review was performed on 48 active obese women and 48 inactive obese women (N.=96) who received prenatal care and delivered at the medical center during the past five years. Obstetric and neonatal outcomes were compared between the active and inactive groups.

RESULTS

Obese women who were active during pregnancy spent less total time in labor (13.4 hours vs. 19.2 hours, P=0.048) and were less likely to request an epidural (92% vs. 100%, P=0.04). When stratified by parity, active multiparous women spent significantly less total time in labor compared to inactive multiparous (6.2 hours vs. 16.7 hours, P=0.018). There were no statistical differences between groups in rates of cesarean deliveries or neonatal outcomes.

CONCLUSIONS

Maternal physical activity during pregnancy appears to improve obstetric outcomes in obese women, and this improvement may be more pronounced among multiparous women. Our finding is of particular importance as pregnant obese women are at higher risk for adverse labor and delivery outcomes.

Influence of obesity on route of delivery in a population of African descent in Martinique

OBJECTIVE

To determine whether obesity is an independent risk factor for cesarean delivery in Martinique.

METHODS

A retrospective study was performed using data for deliveries that occurred at the University Hospital of Fort de France between January and September 2010. Women were divided into four groups on the basis of body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters; < 25 [group 1], 25-29 [group 2], 30-39 [group 3], and ≥ 40 [group 4]). Independent risk factors for cesarean delivery were identified through multivariate analysis.

RESULTS

Overall, 1286 women were included. Mean weight gain was lower in groups 2 (9.9 kg, 95% CI 9.2-10.7), 3 (5.7 kg, 4.7-6.7), and 4 (1.0 kg,-1.5 to 3.5), than in group 1 (12.3 kg, 11.9-12.7; P < 0.001 for all). In univariate analysis, cesarean deliveries were more frequent among nulliparous women in group 2 (P = 0.007) and group 3 (P = 0.053) than among those in group 1. In multivariate analysis, BMI was not associated with cesarean delivery (BMI 25-29: adjusted odds ratio 0.64, 95% CI 0.33-1.25; BMI ≥ 30: 0.61, 0.29-1.39).

CONCLUSION

Obesity was not an independent risk factor for cesarean delivery. Weight control and a positive attitude towards trial of labor in obese women could have led to the findings.

Diabetes in pregnancy: timing and mode of delivery

Diabetes in pregnancy represents a risk condition for adverse maternal and feto-neonatal outcomes and many of these complications might occur during labor and delivery. In this context, the obstetrician managing women with pre-existing and gestational diabetes should consider (1) how these conditions might affect labor and delivery outcomes; (2) what are the current recommendations on management; and (3) which other factors should be considered to decide about the timing and mode of delivery. The analysis of the studies considered in this review leads to the conclusion that the decision to deliver should be primarily intended to reduce the risk of stillbirth, macrosomia, and shoulder dystocia. In this context, this review provides useful information for managing specific subgroups of diabetic women that may present overlapping risk factors, such as women with insulin-requiring diabetes and/or obesity and/or prenatal suspicion of macrosomic fetus. To date, the lack of definitive evidences and the complexity of the problem suggest that the "appropriate" clinical management should be customized according with the clinical condition, the type and mode of intervention, its consequences on outcomes, and considering the woman's consent and informed decisions.