Term Labor Induction and Cesarean Delivery Risk among Obese Women with and without Comorbidities

Contemporary Trends in Cesarean Delivery Rates and Indications

OBJECTIVE

This study aimed to describe cesarean delivery rates and indications at a single center in order to assess the impact of the guidelines published by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine on trends in labor management.

STUDY DESIGN

This is a retrospective cohort study of patients ≥23 weeks' gestation delivering at a single tertiary care referral center from 2013 to 2018. Demographic characteristics, mode of delivery, and main indication for cesarean delivery were ascertained by individual chart review. Cesarean delivery indications (mutually exclusive) were the following: repeat cesarean delivery, nonreassuring fetal status, malpresentation, maternal indications (e.g., placenta previa or genital herpes simplex virus), failed labor (any stage labor arrest), or other (i.e., fetal anomaly and elective). Polynomial (cubic) regression models were used to model rates of cesarean delivery and indications over time. Subgroup analyses further examined trends in nulliparous women.

RESULTS

Of the 24,637 patients delivered during the study period, 24,050 were included in the analysis; 7,835 (32.6%) had a cesarean delivery. The rates of overall cesarean delivery were significantly different over time (p < 0.001), declining to a minimum of 30.9% in 2014 and peaking at 34.6% in 2018. With regard to the overall cesarean delivery indications, there were no significant differences over time. When limited to nulliparous patients, the rates of cesarean delivery were also noted to be significantly different over time (p = 0.02) nadiring at 30% in 2015 from 35.4% in 2013 and then rising up to 33.9% in 2018. As for nulliparous patients, there was no significant difference in primary cesarean delivery indications over time except for nonreassuring fetal status (p = 0.049).

CONCLUSION

Despite changes in labor management definitions and guidelines encouraging vaginal birth, the rates of overall cesarean delivery did not decrease over time. The indications for delivery, particularly failed labor, repeat cesarean delivery, and malpresentation have not significantly changed over time.

KEY POINTS

· The rates of overall cesarean deliveries did not decrease despite the 2014 published recommendations for the reduction in cesarean deliveries.. · There were no significant differences in the indications of cesarean deliveries among nulliparous or multiparous women.. · Despite the adoption of strategies to reduce the overall and primary cesarean delivery rates, these trends remain unchanged.. · Indications for delivery, particularly failed labor, repeat cesarean delivery, and malpresentation have also not significantly changed over time.. · Additional strategies to encourage and increase vaginal delivery rates must be adopted..

Feasibility Study to Compare Oxytocin Function Between Body Mass Index Groups at Term Labor Induction

OBJECTIVE

To determine the feasibility of a protocol to examine the association between oxytocin system function and birth outcomes in women with and without obesity before induction of labor.

DESIGN

Prospective descriptive.

SETTING

Academic medical center in the U.S. Midwest.

PARTICIPANTS

Pregnant women scheduled for induction of labor at 40 weeks of gestation or greater (n = 15 normal weight; n = 15 obese).

METHODS

We collected blood samples and abstracted data by chart review. We used percentages to examine adherence to protocol. We used t tests and chi-square tests to describe differences in sample characteristics, oxytocin system function variables, and birth outcomes between the body mass index groups.

RESULTS

The recruitment rate was 85.7%, protocol adherence was 97.1%, and questionnaire completion was 80.0%. Mean plasma oxytocin concentration was higher in the obese group (M = 2774.4 pg/ml, SD = 797.4) than in the normal weight group (M = 2193.5 pg/ml, SD = 469.8). Oxytocin receptor DNA percentage methylation (CpG -934) was higher in the obese group than in the normal weight group.

CONCLUSION

Our protocol was feasible and can serve as a foundation for estimating sample sizes in forthcoming studies investigating the diversity in oxytocin system measurements and childbirth outcomes among pregnant women in different body mass index categories.

The Influence of Diabetes on Labor Induction with Dinoprostone Vaginal Inserts

OBJECTIVE

The aim of this study was to compare duration of labor induction between diabetic and nondiabetic women receiving dinoprostone vaginal insert (10 mg).

STUDY DESIGN

This is a secondary analysis of two large randomized controlled trials using dinoprostone vaginal inserts for labor induction. We compare time to active labor, overall delivery, and vaginal delivery between diabetic and nondiabetic women undergoing induction of labor with a 10-mg dinoprostone vaginal insert.

RESULTS

Diabetic women receiving dinoprostone vaginal insert had a longer time to onset of active labor, overall delivery, and vaginal delivery than their nondiabetic counterparts. There was no difference in abnormal labor affecting fetal heart rate pattern in diabetic women compared with nondiabetic women. The rates of neonatal hyperbilirubinemia were higher in diabetic women.

CONCLUSION

Diabetes may represent an independent factor associated with prolonged induction among women undergoing induction of labor with dinoprostone. Dinoprostone is well tolerated in both diabetic and nondiabetic women.

KEY POINTS

· Diabetic women receiving DVI have slower labor curves than nondiabetic women.. · Nulliparous diabetic women took longer to achieve active labor, overall delivery, and vaginal delivery than nondiabetic women.. · Parous diabetic women took longer to achieve vaginal delivery than nondiabetic women..

Prenatal Care for the Obese and Severely Obese Pregnant Patient

Modifications of prenatal care will be needed in expected weight gain, nutritional recommendations, screening tests, thromboprophylaxis, ultrasound, antenatal testing, and timing and mode of delivery.

Risk of Cesarean Delivery after Vaginal Inserts with Prostaglandin Analogs and Single-Balloon Catheter Used for Cervical Ripening and Induction of Labor

(1) Background: Induction of labor is currently the most frequently performed procedure in modern obstetrics, referring to more than one in five women, and it is postulated that the percentage of labor induction will increase. (2) Methods: In total, 2935 patients in uncomplicated full-term pregnancy fulfilled the study inclusion criteria and underwent induction of labor. Pregnant women were divided into three groups: IOL with Dinoprostone, Misoprostol vaginal suppositories, and Foley catheter. Outcomes, including cesarean section rates, time to delivery, and cesarean section indications, were analyzed. (3) Results: There was statistically significantly more cesarean sections within 24 h in the Misoprostol group in comparison with the Dinoprostone and Foley catheter groups (p < 0.0001). The percentage of patients who had a cesarean section due to clinically diagnosed threatened fetal asphyxia was 63% in the Dinoprostone group, 81.3% in the Misoprostol group, and 55.3% in the Foley catheter group. There were statistically significantly more cesarean deliveries due to nonreassuring fetal heart rate patterns within 24 h in the Misoprostol group in comparison with the Dinoprostone and Foley catheter groups (p = 0.0031 and p = 0.0363). (4) Conclusions: Misoprostol may cause a more turbulent and violent course of labor, with a higher rate of increased incidence of nonreassuring fetal heart rate patterns and cesarean deliveries. The use of a Dinoprostone vaginal insert or Foley catheter may provide longer labor, although still within 48 h, with a lower risk of cesarean section caused by nonreassuring fetal heart rate patterns.

Full-term induction of labor vs expectant management and cesarean delivery in women with obesity; systematic review and meta-analysis

OBJECTIVE

This study aimed to review the literature comparing full-term induction of labor with expectant management in women with obesity on the risk of cesarean delivery and other adverse outcomes.

DATA SOURCES

A literature search was performed on PubMed, EMBASE, Scopus, ClinicalTrials.gov, and the Cochrane Library. This study had no time, language, or geographic restriction.

STUDY ELIGIBILITY CRITERIA

Studies were eligible if (1) they were cohort or randomized controlled trials, (2) they compared induction of labor at early or late term with expectant management, and (3) they included women with a body mass index of ≥30 kg/m². Studies restricted to women with multiple pregnancy, premature rupture of membranes, or noncephalic presentation were excluded. The primary outcome was cesarean delivery. The secondary outcomes included maternal and neonatal mortality and morbidities and were evaluated.

METHODS

The risk of bias was assessed by 2 authors using the Risk of Bias In Non-Randomized Studies of Interventions tool. Only studies assessed with low or moderate risk of bias contributed to the meta-analysis. Data were combined to pooled relative risks and 95% confidence intervals using random effects models. The quality of evidence was assessed for selected outcomes.

RESULTS

Of the 232 studies identified, 13 were aligned with the inclusion criteria, and 4 cohort studies, including 216,318 women with induction of labor and 1,122,769 women managed expectantly, were included in the meta-analysis for the primary outcome. In women with obesity, full-term induction of labor was associated with a lower risk of cesarean delivery than expectant management (19.7% vs 24.5%; relative risk, 0.71; 95% confidence interval, 0.63-0.81). Moreover, this study found the same direction of the association for other selected outcomes: severe perineal lacerations (relative risk, 0.65; 95% confidence interval, 0.48-0.89), maternal infection (relative risk, 0.42; 95% confidence interval, 0.21-0.84), perinatal mortality (relative risk, 0.41; 95% confidence interval, 0.18-0.90), low Apgar score (relative risk, 0.48; 95% confidence interval, 0.26-0.91), meconium aspiration syndrome (relative risk, 0.40; 95% confidence interval, 0.28-0.56), and macrosomia (relative risk, 0.57; 95% confidence interval, 0.43-0.75). Conversely, induction of labor was associated with an increased risk of instrumental vaginal delivery (relative risk, 1.12; 95% confidence interval, 1.02-1.22). The quality of evidence ranged from low to very low.

CONCLUSION

Full-term induction of labor in women with obesity may reduce the risk of cesarean delivery compared with expectant management, but the quality of the evidence is low.

A double-blinded randomized controlled trial on the effects of increased intravenous hydration in nulliparas undergoing induction of labor

BACKGROUND

Rates of labor induction are increasing, raising concerns related to increased healthcare utilization costs. High-dose intravenous fluid (250 cc/h) has been previously demonstrated to shorten the time to delivery in nulliparous individuals in spontaneous labor. Whether or not this relationship exists among individuals undergoing induction of labor is unknown.

OBJECTIVE

Our study aimed to evaluate the effect of high-dose intravenous hydration on time to delivery among nulliparous individuals undergoing induction of labor.

STUDY DESIGN

Nulliparous individuals presenting for induction of labor with a Bishop score of ≤6 (with and without rupture of membranes) were randomized to receive either 125 cc/h or 250 cc/h of normal saline. The primary outcome was length of labor (defined as time from initiation of study fluids to delivery). Both time to overall delivery and vaginal delivery were evaluated. Secondary outcomes included the lengths of each stage of labor, the percentage of individuals delivering within 24 hours, and maternal and neonatal outcomes, including cesarean delivery rate.

RESULTS

A total of 180 individuals meeting inclusion criteria were enrolled and randomized. Baseline demographic characteristics were similar between groups; however, there was a higher incidence of diabetes mellitus in the group receiving 125 cc/h. Average length of labor was similar between groups (27.6 hours in 250 cc/h and 27.8 hours in 125 cc/h), as was the length of each stage of labor. Cox regression analysis did not demonstrate an effect of fluid rate on time to delivery. Neither the admission Bishop score, body mass index, nor other demographic characteristics affected time to delivery or vaginal delivery. There were no differences in maternal or neonatal outcomes, including overall cesarean delivery rate, clinically apparent iatrogenic intraamniotic infection, Apgar scores, need for neonatal phototherapy, or neonatal intensive care unit stay.

CONCLUSION

There were no observed differences in the length of labor or maternal or neonatal outcomes with the administration of an increased rate of intravenous fluids among nulliparous individuals undergoing induction of labor.

Is Misoprostol Vaginal Insert Safe for the Induction of Labor in High-Risk Pregnancy Obese Women?

Induction of labor (IOL) is an event that occurs in up to 25% of pregnancies. In Europe, the misoprostol vaginal insert (MVI—Misodel^®) was approved for labor induction in 2013. Studies on the outcomes and safety of IOL in obese pregnant women are scarce; no data are available on MVI IOL in high-risk pregnancy obese women (HRPO—late-term, hypertension, diabetes). As the obesity rates are growing steadily in pregnant women, we aimed to evaluate the failure rate for induction and the safety of a 200 μg MVI in obese (body mass index (BMI) >30 kg/m²) HRPO compared to that for obese non-high-risk pregnancies (non-HRPO). For this purpose, we conducted a cross-sectional study in “Filantropia” Clinical Hospital, Bucharest, Romania, from June 2017—the date of the initiation of the MVI IOL protocol in our clinic—to September 2019. The primary outcomes were the failure rate, measured by cesarean section (CS) ratio, and secondarily, the safety profile of MVI, analyzed by one-way ANOVA. Out of a total of 11,096 registered live births, IOL was performed on 206 obese patients. Of these, 74 obese pregnant women had their labor induced with MVI (HRPO, n = 57, and non-HRPO, n = 17). The average maternal age was 29.9 ± 4.8 years (19–44 years). Across the groups, the rate of CS was 29.8% (n = 17) in the HRPO group compared to 23.5% (n = 4) in the non-HRPO group (p = non significant). In the vaginally birth subgroups, the median time from drug administration to delivery was shorter in the HRPO group compared to the non-HRPO group (16.9 ± 6.0 h 95% confidence interval (CI) 15.0–18.8 vs. 19.4 ± 9.2 h 95% CI 13.8–25.0, p = 0.03). No significant differences were found regarding the maternal outcomes among the studied groups; in terms of perinatal outcomes of safety, 5.4% (n = 4) of the cases of vaginal delivery for HRPO were associated with neonatal intensive care unit (NICU) admissions. The MVI seems to be an efficient labor induction agent in high-risk pregnancy obese women with good maternal outcomes and low perinatologic complications.