Dwight J. Rouse

Development of a nomogram for prediction of vaginal birth after cesarean delivery.

OBJECTIVE: To develop a model based on factors available at the first prenatal visit that predicts chance of successful vaginal birth after cesarean delivery (VBAC) for individual patients who undergo a trial of labor. METHODS: All women with one prior low transverse cesarean who underwent a trial of labor at term with a vertex singleton gestation were identified from a concurrently collected database of deliveries at 19 academic centers during a 4-year period. Using factors identifiable at the first prenatal visit, we analyzed different classification techniques in an effort to develop a meaningful prediction model for VBAC success. After development and cross-validation, this model was represented by a graphic nomogram. RESULTS: Seven-thousand six hundred sixty women were available for analysis. The prediction model is based on a multivariable logistic regression, including the variables of maternal age, body mass index, ethnicity, prior vaginal delivery, the occurrence of a VBAC, and a potentially recurrent indication for the cesarean delivery. After analyzing the model with cross-validation techniques, it was found to be both accurate and discriminating. CONCLUSION: A predictive nomogram, which incorporates six variables easily ascertainable at the first prenatal visit, has been developed that allows the determination of a patient-specific chance for successful VBAC for those women who undertake trial of labor. LEVEL OF EVIDENCE: II

Labor outcomes with increasing number of prior vaginal births after cesarean delivery

OBJECTIVE: To estimate the success rates and risks of an attempted vaginal birth after cesarean delivery (VBAC) according to the number of prior successful VBACs. METHODS: From a prospective multicenter registry collected at 19 clinical centers from 1999 to 2002, we selected women with one or more prior low transverse cesarean deliveries who attempted a VBAC in the current pregnancy. Outcomes were compared according to the number of prior VBAC attempts subsequent to the last cesarean delivery. RESULTS: Among 13,532 women meeting eligibility criteria, VBAC success increased with increasing number of prior VBACs: 63.3%, 87.6%, 90.9%, 90.6%, and 91.6% for those with 0, 1, 2, 3, and 4 or more prior VBACs, respectively (P<.001). The rate of uterine rupture decreased after the first successful VBAC and did not increase thereafter: 0.87%, 0.45%, 0.38%, 0.54%, 0.52% (P=.03). The risk of uterine dehiscence and other peripartum complications also declined statistically after the first successful VBAC. No increase in neonatal morbidities was seen with increasing VBAC number thereafter. CONCLUSION: Women with prior successful VBAC attempts are at low risk for maternal and neonatal complications during subsequent VBAC attempts. An increasing number of prior VBACs is associated with a greater probability of VBAC success, as well as a lower risk of uterine rupture and perinatal complications in the current pregnancy. LEVEL OF EVIDENCE: II

Morbidly Adherent Placenta Treatments and Outcomes

OBJECTIVE: To describe recent maternal and neonatal delivery outcomes among women with a morbidly adherent placenta in major centers across the United States. METHODS: This study reviewed a cohort of 115,502 women and their neonates born in 25 hospitals in the United States between March 2008 and February 2011 from the Assessment of Perinatal EXcellence data set. All cases of morbidly adherent placenta were identified. Maternal demographics, procedures undertaken, and maternal and neonatal outcomes were analyzed. RESULTS: There were 158 women with a morbidly adherent placenta (1/731 births, 95% confidence interval 1/632–866). Eighteen percent of women with a morbidly adherent placenta were nulliparous and 37% had no prior cesarean delivery. Only 53% (84/158) were suspected to have a morbidly adherent placenta before delivery. Women with a prenatally suspected morbidly adherent placenta experienced large blood loss (33%), hysterectomy (92%), and intensive care unit admission (39%) compared with 19%, 45%, and 22%, respectively, in those not suspected prenatally to have a morbidly adherent placenta (P<.05 for all). CONCLUSION: Eighteen percent of women with a morbidly adherent placenta were nulliparous. Half of the morbidly adherent placenta cases were suspected before delivery and outcomes were poorer in this group, probably because the more clinically significant morbidly adherent placentas are more likely to be suspected before delivery. LEVEL OF EVIDENCE: II

Can a prediction model for vaginal birth after cesarean also predict the probability of morbidity related to a trial of labor

OBJECTIVEnThe objective of the study was to determine whether a model for predicting vaginal birth after cesarean (VBAC) can also predict the probabilty of morbidity associated with a trial of labor (TOL).nnnSTUDY DESIGNnUsing a previously published prediction model, we categorized women with 1 prior cesarean by chance of VBAC. Prevalence of maternal and neonatal morbidity was stratfied by probability of VBAC success and delivery approach.nnnRESULTSnMorbidity became less frequent as the predicted chance of VBAC increased among women who underwent TOL (P < .001) but not elective repeat cesarean section (ERCS) (P > .05). When the predicted chance of VBAC was less than 70%, women undergoing a TOL were more likely to have maternal morbidity (relative risk [RR], 2.2; 95% confidence interval [CI], 1.5-3.1) than those who underwent an ERCS; when the predicted chance of VBAC was at least 70%, total maternal morbidity was not different between the 2 groups (RR, 0.8; 95% CI, 0.5-1.2). The results were similar for neonatal morbidity.nnnCONCLUSIONnA prediction model for VBAC provides information regarding the chance of TOL-related morbidity and suggests that maternal morbidity is not greater for those women who undergo TOL than those who undergo ERCS if the chance of VBAC is at least 70%.

Elective repeat cesarean delivery compared with spontaneous trial of labor after a prior cesarean delivery: a propensity score analysis.

OBJECTIVEnThe purpose of this study was to determine outcomes, after the use of propensity score techniques, to create balanced groups according to whether a woman undergoes elective repeat cesarean delivery (ERCD) or trial of labor (TOL).nnnSTUDY DESIGNnWomen who were eligible for a TOL with 1 previous low transverse incision were categorized according to whether they underwent an ERCD or TOL. A propensity score technique was used to develop ERCD and TOL groups with comparable baseline characteristics. Outcomes were assessed with conditional logistic regression.nnnRESULTSnThe rates of endometritis, operative injury, respiratory distress syndrome, and newborn infant infection were lower and the rates of hysterectomy and wound complication were higher in the ERCD group.nnnCONCLUSIONnPropensity score techniques can be used to generate comparable ERCD and TOL groups. Some types of maternal morbidity (such as hysterectomy) are higher; other types (such as operative injury) are lower in the ERCD group. Although the absolute risk is low, neonatal morbidity appears to be lower in the ERCD group.

MODE OF DELIVERY IN WOMEN WITH ANTEPARTUM FETAL DEATH AND PRIOR CESAREAN DELIVERY

We describe obstetric outcomes in a group of patients with prior cesarean delivery (CD) presenting with an intrauterine fetal demise (IUFD). A secondary analysis of an observational study of women with prior CD was performed. All antepartum singleton pregnancies with a prior CD and IUFD ≥20 weeks gestation or 500 g were evaluated. Two hundred nine patients met inclusion criteria for analysis. The mean gestational ageu2009±u2009standard deviation at delivery was 31.3u2009±u20096.5 weeks. The trial of labor rate was 75.6% (158/209), and the vaginal birth after cesarean (VBAC) success rate was 86.7%. Labor induction or augmentation occurred in 83.3% of attempted VBAC. Uterine rupture occurred in five women (2.4%), and in 3.4% of those being induced but none of these required hysterectomy. Women with a history of previous CD and an IUFD often undergo trial of labor with a high VBAC success rate. Uterine rupture complicates 2.4% of such cases.

Trial of Labor After One Previous Cesarean Delivery for Multifetal Gestation

OBJECTIVE: To estimate success rates and risks with a trial of labor after one previous cesarean delivery for multifetal gestation compared with one previous cesarean delivery for a singleton pregnancy. METHODS: Patients from the National Institute of Child Health and Human Development Maternal Fetal Medicine Units Network Cesarean Registry with one previous cesarean delivery and a current term singleton pregnancy were identified. Cases had one previous cesarean delivery for a multifetal pregnancy. Controls had one previous cesarean delivery for a singleton pregnancy. RESULTS: Of cases, 556 of 944 (58.9%) attempted a trial of labor. Of controls, 13,923 of 29,329 (47.5%) attempted a trial of labor. The trial of labor success rate was 85.6% among cases and 73.1% among controls (odds ratio 2.19, 95% confidence interval 1.72–2.78). Compared with trial of labor controls, cases had no statistically increased risk of transfusion, endometritis, intensive care unit admissions, uterine rupture, or perinatal complications. Cases in this analysis with a successful trial of labor were more likely to have previously had a successful vaginal birth after cesarean (37.1% compared with 14.1%, P<.001). CONCLUSION: Women with one previous cesarean delivery for a multifetal gestation have high trial of labor success rates and low complication rates. LEVEL OF EVIDENCE: II

White's classification of maternal diabetes and vaginal birth after cesarean delivery success in women undergoing a trial of labor

OBJECTIVE: To estimate the rate of vaginal birth after cesarean delivery (VBAC) success in diabetic women based on White’s Classification. METHODS: This is a secondary analysis of an observational study conducted at 19 medical centers of women attempting VBAC. Diabetic women with singleton gestations, one prior cesarean delivery, and cephalic presentation who underwent a trial of labor were included. Vaginal birth after cesarean delivery success rates and maternal and neonatal complications were compared based on White’s Classification. RESULTS: Of 11,856 women who underwent trial of labor, 624 met all study criteria (class A1, 356; A2, 169; B, 70; C, 21; D/R/F, 8). Vaginal birth after cesarean delivery success in each group was: A1, 68.5% (95% confidence interval [CI] 63.4–73.3%); A2, 55% (95% CI 47.2–62.7%); B, 70% (95% CI 57.9–80.4%); C, 47.6% (95% CI 25.7–70.2%); and D/F/R, 12.5% (95% CI 0.3–52.7%). Maternal and neonatal complications were rare and not found to be different among groups. CONCLUSION: Our study provides estimates for VBAC success based on White’s classification and indicates a relatively low rate of perinatal complications after VBAC attempt for diabetic women. LEVEL OF EVIDENCE: III