Population adjustment of the definition of the vaginal birth after cesarean rate.

OBJECTIVE: The vaginal birth after cesarean delivery rate is calculated with a denominator equal to the number of all women who give birth after a previous cesarean delivery, including those who are not candidates for a trial of labor. We evaluated the impact of adjustment for noncandidates for a trial of labor on vaginal birth after cesarean delivery rates. STUDY DESIGN: All women with a previous cesarean delivery who were delivered during 1998 were classified as either candidates or noncandidates for a trial of labor. An adjusted vaginal birth after cesarean delivery rate was calculated by eliminating noncandidates for a trial of labor from the denominator. The percentage of noncandidates for a trial of labor, the vaginal birth after cesarean delivery rate, and the adjusted vaginal birth after cesarean delivery rate were compared among 3 clinical services. RESULTS: The maternal-fetal medicine service had a significantly higher percentage of noncandidates for a trial of labor than did either the low-risk resident clinic or the low-risk private service. The maternal-fetal medicine service had a significantly lower vaginal birth after cesarean delivery rate than did the private service, but this difference was no longer present after application of an adjusted vaginal birth after cesarean delivery definition. CONCLUSION: For accurate comparison of vaginal birth after cesarean delivery rates among providers it is essential to account for patient risk status in the vaginal birth after cesarean delivery definition through the elimination of noncandidates for a trial of labor.

Prediction of preterm delivery with transvaginal ultrasonography of the cervix in patients with high-risk pregnancies: does cerclage prevent prematurity?

OBJECTIVES: We sought to determine the predictive accuracy for preterm delivery of transvaginal ultrasonography of the cervix between 14 and 24 weeks' gestation in high-risk patients and to determine whether cerclage prevents preterm delivery in patients with ultrasonographic cervical changes. STUDY DESIGN: Patients with asymptomatic singleton pregnancies at high risk for preterm delivery were followed prospectively from 14 weeks' to 23 weeks 6 days' gestation with transvaginal ultrasonography of the cervix. The subgroup of patients with either a cervical length of <25 mm or funneling of >25% or both was offered McDonald salvage cerclage, which was performed at the discretion of the patient and the obstetrician. The 2 groups (with and without cerclage) were compared for the primary outcome of preterm delivery at <35 weeks' gestation. RESULTS: One hundred sixty-eight women were followed, including 97 (58%) with >/=1 prior 14- to 34-week preterm deliveries. Of 63 (37. 5%) patients identified as having cervical changes, 23 (37%) had preterm delivery; of 105 patients with no cervical changes, 8 (8%) had preterm delivery (relative risk, 4.8; 95% confidence interval, 2. 3-10.1). The sensitivity, specificity, and positive and negative predictive values of either a short cervix of <25 mm or funneling of >25% or both were 74%, 70%, 37%, and 92%, respectively. Of 63 pregnancies in which there were cervical changes, 39 underwent cerclage and 24 did not. These 2 groups were similar for demographic characteristics, risk factors, and transvaginal ultrasonographic cervical length and funneling but dissimilar for gestational age at identification of cervical changes (18.3 vs 21.2 weeks' gestation in the groups with and without cerclage, respectively; P <.001). Multivariate logistic regression analysis after adjustment for gestational age at cervical changes showed no difference in the rate of preterm delivery between the groups with and without cerclage (odds ratio, 1.1; 95% confidence interval, 0.3-4.6). Stratified analysis of patients identified between 18 and 24 weeks revealed 22 pregnancies with cerclage and 22 pregnancies without cerclage, which was similar for all characteristics studied. The incidence of preterm delivery remained similar (27% vs 23%, respectively; P =.7), as did days from cervical changes to delivery (111 vs 96, respectively; P =.2). CONCLUSIONS: Transvaginal ultrasonography of the cervix between 14 and 24 weeks' gestation is a good predictor of preterm delivery in high-risk pregnancies. Cerclage may not prevent preterm delivery in patients identified to be at high risk for this outcome by transvaginal ultrasonography.

Initial multicenter experience with double nucleoside therapy for human immunodeficiency virus infection during pregnancy.

OBJECTIVE: To study maternal and neonatal effects of combination nucleoside analog therapy administered to human immunodeficiency virus (HIV)-infected pregnant women for maternal indications. METHODS: A multicenter, prospective observational study was undertaken at six perinatal centers in the United States and Canada that supported regional referral programs for the treatment of HIV-infected pregnant women. Demographic, laboratory, and pregnancy outcome data were collected for 39 women whose antiretroviral treatment regimens were expanded to include more than one nucleoside analog for maternal indications. The 40 newborns were monitored at pediatric referral centers through at least three months of age to ascertain their HIV infection status. RESULTS: For all 39 women, zidovudine (ZDV) therapy was instituted at 13.4 +/- 8.2 weeks, with a second agent (lamivudine [3TC] in 85% of cases) being added at a mean gestational age of 17.6 weeks. Duration of therapy with two agents was 20.6 +/- 10.4 weeks overall, with no women stopping medications because of side effects or toxicity. No significant changes in maternal laboratory values were seen, except for an increase in mean corpuscular volume, over the course of pregnancy. No clinically significant adverse neonatal outcomes were noted, with all but the three preterm newborns leaving hospital with their mothers. Neonatal anemia (hematocrit < 50%) was seen in 62% of newborns, with no children needing transfusion; mild elevations of liver function tests, primarily aspartate aminotransferase, were noted in 58% of newborns tested, though none were clinically jaundiced. Overall rate of neonatal HIV infection was 2.5% (95% confidence interval: 0.1-13.2%). CONCLUSION: Combination antiretroviral therapy during pregnancy with two nucleoside analogs was well-tolerated by mothers and newborns, with no significant short-term toxicities or side effects noted. Surveillance of exposed newborns' hematologic and liver function appears warranted.