The proportion of women who attempt vaginal delivery after prior cesarean delivery has decreased largely because of concern about safety. The absolute and relative risks associated with a trial of labor in women with a history of cesarean delivery, as compared with elective repeated cesarean delivery without labor, are uncertain.
Methods
We conducted a prospective four-year observational study of all women with a singleton gestation and a prior cesarean delivery at 19 academic medical centers. Maternal and perinatal outcomes were compared between women who underwent a trial of labor and women who had an elective repeated cesarean delivery without labor.
Results
Vaginal delivery was attempted by 17,898 women, and 15,801 women underwent elective repeated cesarean delivery without labor. Symptomatic uterine rupture occurred in 124 women who underwent a trial of labor (0.7 percent). Hypoxic-ischemic encephalopathy occurred in no infants whose mothers underwent elective repeated cesarean delivery and in 12 infants born at term whose mothers underwent a trial of labor (P<0.001). Seven of these cases of hypoxic-ischemic encephalopathy followed uterine rupture (absolute risk, 0.46 per 1000 women at term undergoing a trial of labor), including two neonatal deaths. The rate of endometritis was higher in women undergoing a trial of labor than in women undergoing repeated elective cesarean delivery (2.9 percent vs. 1.8 percent), as was the rate of blood transfusion (1.7 percent vs. 1.0 percent). The frequency of hysterectomy and of maternal death did not differ significantly between groups (0.2 percent vs. 0.3 percent, and 0.02 percent vs. 0.04 percent, respectively).
Conclusions
A trial of labor after prior cesarean delivery is associated with a greater perinatal risk than is elective repeated cesarean delivery without labor, although absolute risks are low. This information is relevant for counseling women about their choices after a cesarean section. Copyright 2004 Massachusetts Medical Society.
Pineles BL et al., 2023·AJOG Glob Rep·
Open Access
Cesarean delivery is a major source of maternal morbidity, and repeat cesarean delivery accounts for 40% of cesarean delivery, but recent data on the trial of labor after cesarean and vaginal birth after cesarean are limited. This study aimed to report the national rates of trial of labor after cesarean and vaginal birth after cesarean by number of previous cesarean deliveries and examine the effect of demographic and clinical characteristics on these rates. This was a population-based cohort study using the US natality data files. The study sample was restricted to 4,135,247 nonanomalous singleton, cephalic deliveries between 37 and 42 weeks of gestation, with a history of previous cesarean delivery and delivered in a hospital between 2010 and 2019. Deliveries were grouped by number of previous cesarean deliveries (1, 2, or ≥3). The trial of labor after cesarean (deliveries with labor among deliveries with previous cesarean delivery) and vaginal birth after cesarean (vaginal deliveries among trial of labor after cesarean) rates were computed for each year. The rates were further subgrouped by history of previous vaginal delivery. Year of delivery, number of previous cesarean deliveries, history of previous cesarean delivery, age, race and ethnicity, maternal education, obesity, diabetes mellitus, hypertension, inadequate prenatal care, Medicaid payer, and gestational age were examined concerning the trial of labor after cesarean and vaginal birth after cesarean using multiple logistic regression. SAS software (version 9.4) was used for all analyses. The trial of labor after cesarean rates increased from 14.4% in 2010 to 19.6% in 2019 (P<.001). This trend was seen in all categories of number of previous cesarean deliveries. Moreover, vaginal birth after cesarean rates increased from 68.5% in 2010 to 74.3% in 2019. The trial of labor after cesarean and vaginal birth after cesarean rates were the highest for deliveries with a history of both 1 previous cesarean delivery and a vaginal delivery (28.9% and 79.7%, respectively) and the lowest for those with a history of ≥3 previous cesarean deliveries and no history of vaginal delivery (4.5% and 46.9%, respectively). Factors associated with the trial of labor after cesarean and vaginal birth after cesarean rates are similar, but several factors have different directions of effect, such as non-White race and ethnicity, which is associated with a higher likelihood of trial of labor after cesarean but a lower likelihood of successful vaginal birth after cesarean. More than 80% of patients with a history of previous cesarean delivery deliver by repeat scheduled cesarean delivery. With vaginal birth after cesarean rates increasing among those who attempt a trial of labor after cesarean, emphasis should be put on safely increasing the trial of labor after cesarean rates.
Marshall NE et al., 2011·American Journal of Obstetrics and Gynecology
The purpose of this study was to determine the impact of increasing numbers of cesarean deliveries on maternal morbidity. This study was performed for the 2010 National Institutes of Health Consensus Development Conference on Vaginal Birth After Cesarean: New Insights. We conducted a systematic review and metaanalysis of observational studies. Twenty-one studies (2,282,922 deliveries) were included. The rate of hysterectomy, blood transfusions, adhesions, and surgical injury all increased with increasing number of cesarean deliveries. The incidence of placenta previa increased from 10/1000 deliveries with 1 previous cesarean delivery to 28/1000 with ≥3 cesarean deliveries. Compared with women with previa and no previous cesarean delivery, women with previa and ≥3 cesarean deliveries had a statistically significant increased risk of accreta (3.3-4% vs 50-67%), hysterectomy (0.7-4% vs 50-67%), and composite maternal morbidity (15% vs 83%; odds ratio, 33.6; 95% confidence interval, 14.6-77.4). Serious maternal morbidity progressively increased as the number of previous cesarean deliveries increased.
Coomarasamy A et al., 2019·N Engl J Med·
Open Access
Bleeding in early pregnancy is strongly associated with pregnancy loss. Progesterone is essential for the maintenance of pregnancy. Several small trials have suggested that progesterone therapy may improve pregnancy outcomes in women who have bleeding in early pregnancy. We conducted a multicenter, randomized, double-blind, placebo-controlled trial to evaluate progesterone, as compared with placebo, in women with vaginal bleeding in early pregnancy. Women were randomly assigned to receive vaginal suppositories containing either 400 mg of progesterone or matching placebo twice daily, from the time at which they presented with bleeding through 16 weeks of gestation. The primary outcome was the birth of a live-born baby after at least 34 weeks of gestation. The primary analysis was performed in all participants for whom data on the primary outcome were available. A sensitivity analysis of the primary outcome that included all the participants was performed with the use of multiple imputation to account for missing data. A total of 4153 women, recruited at 48 hospitals in the United Kingdom, were randomly assigned to receive progesterone (2079 women) or placebo (2074 women). The percentage of women with available data for the primary outcome was 97% (4038 of 4153 women). The incidence of live births after at least 34 weeks of gestation was 75% (1513 of 2025 women) in the progesterone group and 72% (1459 of 2013 women) in the placebo group (relative rate, 1.03; 95% confidence interval [CI], 1.00 to 1.07; P = 0.08). The sensitivity analysis, in which missing primary outcome data were imputed, resulted in a similar finding (relative rate, 1.03; 95% CI, 1.00 to 1.07; P = 0.08). The incidence of adverse events did not differ significantly between the groups. Among women with bleeding in early pregnancy, progesterone therapy administered during the first trimester did not result in a significantly higher incidence of live births than placebo. (Funded by the United Kingdom National Institute for Health Research Health Technology Assessment program; PRISM Current Controlled Trials number, ISRCTN14163439.).