Obstetric antecedents to apparent stillbirth (Apgar score zero at 1 minute only)

To identify antecedent risk factors for the delivery of an infant with an Apgar score of 0 at 1 minute who is subsequently successfully resuscitated.

Infants born between January 1986 and February 1999 with 1-minute Apgar score of 0 followed by 5-minute Apgar score above 0 were studied. Each eligible infant was randomly matched with two control infants, born in the same year, with 1-minute Apgar score greater than 0. Hospital records of their mothers were reviewed. The variables were compared between the groups by univariate analysis. Those factors demonstrating significant differences were then analyzed by logistic regression. P <.05 was considered statistically significant.

Seventy-four of 81,603 infants (0.9:1000 births) born with an Apgar score of 0 at 1 minute only were compared with 148 control babies. Univariate analysis revealed significant differences between study and control group regarding: gestational age, abruptio placentae, preterm premature rupture of membranes, chorioamnionitis, preeclampsia, small-for-gestational age, male gender, bradycardia, and abnormal fetal heart rate (FHR) other than bradycardia, respectively. Logistic regression of these factors found gestational age, bradycardia, and abnormal FHR to be independent risk factors for the delivery of an apparent stillborn infant. After exclusion of FHR criteria, logistic regression found gestational age (odds ratio [OR] 0.8 per week), male gender (OR 2.5), preeclampsia (OR 3.9), and abruptio placentae (OR 13.6) to be independent risk factors for the delivery of an apparent stillborn infant.

Preterm birth, male gender, preeclampsia, and abruptio placentae are independently associated with an increased risk of apparent stillbirth.