Effect of nonviable infants on the infant mortality rate in Philadelphia, 1992

Objectives. This report measured the effect of births at 22 weeks gestation or earlier on infant mortality in Philadelphia, Pa. Methods. The proportion of live-born deliveries at 22 weeks or earlier was calculated after excluding live-born deliveries at 22 weeks gestation or ea rlier. Results. Of all deliveries, 1.5% were at 22 weeks or earlier. Of these, 68% were stillborn and 32% were live-born. Large hospital-to-hospital variatio n in he proportion of live-born deliveries at 22 weeks' gestation or earlie r was noted. When nonviable births were excluded, overall infant mortality decreased 40%. Conclusions. The development of a standardized birth certificate policy is needed and will facilitate comparisons of infant mortality across spatial b oundaries and racial/ethnic groups.