Medline ® Abstracts for References 30-32

In order to assess the current management of, and to develop a management scheme for, patients with postterm pregnancy and previous cesarean section (C/S), a retrospective analysis of 112 patients was done. All patients with postdates pregnancy and previous C/S were followed in a postdates clinic according to a previously published protocol. Thirty-four patients (30.4%) underwent elective repeat C/S, and 78 (69.6%) were permitted a trial of labor (TOL). Of these TOL patients, 57 (73.1%) delivered vaginally. Sixteen (42.2%) of 37 patients with a history of prior C/S for cephalopelvic disproportion delivered vaginally. Excluding 34 patients who underwent elective repeat C/S, the remaining 41 patients who had previous C/Ss for other indications delivered vaginally. This difference was statistically significant (p less than 0.001). Other factors--the number of previous vaginal deliveries, type of previous-C/S incision, the complications of the prior C/S and the interval since the previous C/S occurred--had no effect on vaginal delivery. There was no marked difference in perinatal morbidity between infants delivered vaginally and those delivered abdominally. The maternal morbidity, in terms of postpartum fever and requirement for transfusion, in patients with repeat C/S was significantly higher than that in women with vaginal deliveries. Postdates pregnancy was not associated with an increased risk of uterine rupture. On the basis of this experience we think that postterm pregnancy should not be considered a contraindication to a TOL.

OBJECTIVE: To compare outcomes in women with prior cesareans delivering at or before 40 weeks' gestation with those delivering after 40 weeks. METHODS: We reviewed labor outcomes over 12 years at one institution for women with one prior cesarean and no other deliveries who had a trial of labor at term. We analyzed the rates of symptomatic uterine rupture and cesarean for term deliveries before or after 40 weeks and stratified for spontaneous and induced labor. Potential confounding by birth weight was controlled using logistic regression. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: Of 2775 women with one prior scar and no other deliveries, 1504 delivered at or before 40 weeks and 1271 delivered after 40 weeks. For spontaneous labor, rupture rate at or before 40 weeks was 0.5% compared with 1.0% after 40 weeks (P =.2, adjusted OR 2.1, CI 0.7, 5.7). For induced labor, uterine rupture rates were 2.1% at or before 40 weeks and 2.6% after 40 weeks (P =.7, adjusted OR 1.1, CI 0.4, 3.4). For spontaneous labor, rate of cesareans during subsequent trials of labor at or before 40 weeks was 25% compared with 33.5% after 40 weeks (P =.001, adjusted OR 1.5, CI 1.2, 1.8). For induced labor, rate of cesareans during subsequent trials of labor at or before 40 weeks was 33.8% compared with 43% after 40 weeks (P =.03, adjusted OR 1.5, CI 1.1, 2.2). CONCLUSION: The risk of uterine rupture does not increase substantially after 40 weeks but is increased with induction of labor regardless of gestational age. Because spontaneous labor after 40 weeks is associated with a cesarean rate similar to that following induced laborbefore 40 weeks, awaiting spontaneous labor after 40 weeks does not decrease the likelihood of successful vaginal delivery.

OBJECTIVE: To compare rates of vaginal birth after cesarean (VBAC) failure and major complications in women attempting VBAC before and after the estimated date of delivery (EDD) METHODS: This was a 5-year retrospective cohort study in 17 university and community hospitals of women with at least 1 prior cesarean delivery. Women who attempted VBAC before the EDD were compared with those at or beyond 40 weeks of gestation. Logistic regression analyses were performed to assess the relationship between delivery beyond the EDD and VBAC failure or complication rate. RESULTS: A total of 11,587 women in the cohort attempted VBAC. Women past 40 weeks of gestation were more likely to have a failed VBAC. After controlling for confounders, the increased risk of a failed VBAC beyond 40 weeks remained significant (31.3% compared with 22.2%, odds ratio 1.36, 95% confidence interval 1.24-1.50). The risk of uterine rupture (1.1% compared with 1.0%) or overall morbidity (2.7% compared with 2.1%) was not significantly increased in the women attempting VBAC beyond the EDD. When the cohort was defined as 41 weeks or more of gestation, the risk of a failed VBAC was again significantly increased (35.4% compared with 24.3%, odds ratio 1.35, 95% confidence interval 1.20-1.53), but the risk of uterine rupture or overall morbidity was not increased. CONCLUSION: Women beyond 40 weeks of gestation can safely attempt VBAC, although the risk of VBAC failure is increased. LEVEL OF EVIDENCE: II-2.