Short-term neonatal morbidity associated with prematurity and the effect of a prematurity prevention program on expected incidence of morbidity.

With recent advances in neonatal medicine, the risk of mortality for premature newborns has been markedly reduced. Attention has shifted to the morbidity associated with preterm delivery. Consideration of anticipated neonatal morbidity at a particular gestational age plays an important part in the decision of whether or not to treat preterm labor. We have assessed eight indices of short-term morbidity in 170 liveborn infants delivered between 26 and 35 completed weeks of gestation and calculated the gestational age-specific rates of each measure of morbidity. Five measures of short-term morbidity were significantly reduced by extending the gestation from 34 to 35 weeks. To illustrate the effect of prolonged pregnancy on the incidence of short-term neonatal morbidity, the actual incidence of morbidity from a group of preterm labor patients who were part of a preterm birth prevention program was compared to the anticipated incidence of these same morbidity factors has birth occurred when preterm labor was first diagnosed. There was a significant decrease in the number of observed, as opposed to anticipated, neonatal deaths and in morbidity occurrences in four of the six factors tested. Implications for considering short-term neonatal morbidity in the decision to initiate treatment for preterm labor after 33 weeks gestation are discussed.