A population-based analysis of risk factors for obstetrical brachial plexus palsy in neonates delivered by vacuum extraction: an analysis based on 13,716 deliveries

ULATION-BASED STUDY JUN ZHANG, BRADY HAMILTON, JOYCE MARTIN, ANN TRUMBLE, National Institutes of Health, Epidemiology Branch, Bethesda, MD National Center for Health Statistics, Hyattsville, MD National Institutes of Health, Bethesda, MD OBJECTIVE: The number of multifetal pregnancies has increased dramatically. Cases such as premature rupture of the membranes of one fetus, single fetal demise, and premature labor in extreme preterm are encountered more often than before. Delaying delivery of the remaining fetus(es) is feasible in some cases. However, benefits and risks of this procedure have yet to be established. STUDY DESIGN: We used the U.S. 1995-98 Matched Multiple Birth File to examine infant survival after delayed interval delivery. We identified 200 twin pregnancies in which the first twin was delivered between 17 and 29 weeks of gestation and the second twin was delivered at least 24 hours later. We individually matched the delayed deliveries with 374 twin pregnancies in which delivery of second twin was not delayed. Perinatal outcomes and infant survival were compared between the delayed and non-delayed twins. RESULTS: Among the 200 pregnancies with delayed delivery, the mean gestational age at first delivery was 23 weeks and the median duration of delay was 6 days (ranging from 2 to 107 calendar days). With every week of delay in delivery, the fetus gained 131 grams on average (95% CI: 115-147 g). 56% of the delayed second twins survived to 1 year of age (95% CI: 50-64%) while only 24% of the non-delayed second twins did so (95% CI: 20-29%) (P < 0.001). The delayed twins also had significantly higher Apgar scores at 5 minutes. However, delayed delivery was also associated with 11% of risk (95% CI: 6-16%) for fetal death of the remaining twin before 24 weeks. CONCLUSION: Delaying delivery of the remaining fetus(es) before 30 weeks of gestation improves infant survival by more than twofold and, probably, reduces long-term child morbidity by increasing birthweight and Apgar score at 5 minutes.