Factors influencing neonatal outcomes in the very-low-birth-weight fetus (< 1500 grams) with a breech presentation.

OBJECTIVES

Our purpose was to evaluate factors that may influence perinatal outcomes in the very-low-birth-weight infant with breech presentation.

STUDY DESIGN

An observational study that included all consecutive singletons and twins with the first fetus with breech presentation weighing between 500 and 1500 gm delivered at Chicago Lying-In Hospital from July 1980 to December 1987 was performed. Uncorrected and corrected perinatal mortality and morbidity were calculated. After correction, the effect of mode of delivery (vaginal versus cesarean section) was studied. A further correction was made by excluding cesarean sections performed for fetal distress. Statistical methods included chi 2 and Fisher exact tests and logistic regression analyses to calculate unadjusted and adjusted odds ratios.

RESULTS

Of the 262 fetuses studied, nearly 60% were delivered vaginally and were of younger gestational age and lower fetal weight (300 gm) than those delivered abdominally. Forty-four percent weighed < or = 800 gm, and the perinatal mortality rate was 64.5% (53.3% after correction). Vaginal delivery had higher rates of depression, respiratory distress syndrome, and death. Prematurity was the most frequent cause of neonatal death. The corrected neonatal mortality was similar to the total inborn population of our neonatal intensive care unit for the same years. Logistic regression analyses revealed that the differences in outcomes between the two groups were primarily related to effects of gestational age, fetal weight, and year of delivery. After these factors were adjusted for, the odds of neonatal death for vaginal delivery compared with cesarean delivery were not significantly different (odds ratio 1.4, 95% confidence interval 0.6 to 3.5, p = 0.48). However, in the subgroup in footling attitude the differences were much greater, with an adjusted odds ratio of 3.2 (95% confidence interval 0.7 to 14.9, p = 0.13).

CONCLUSION

The exceedingly poor perinatal outcomes of very-low-birth-weight breech infants are mainly related to antenatal deaths (22%), extremely low birth weight (44%), congenital malformations, and premature labor, not to the breech presentation. The route of delivery did not significantly influence outcome among complete and frank attitudes; abdominal delivery may offer some benefit for footlings. Prematurity is the primary cause of death of normal very-low-birth-weight breech-delivered infants.