Placental pathology is not predictive for sudden infant death syndrome (SIDS)

A previous report has suggested an increased incidence of chorioamnionitis in the placentae of sudden infant death syndrome (SIDS) victims. To further evaluate placental pathology in SIDS, 27 cases were identified from coroner's records and matched to two control groups. Both control groups were matched for birthweight, gestational age, and season, with the second also matched for maternal race, infant sex, blood type B, and maternal parity. No significant increase in chorioamnionitis or other placental abnormalities were found in SIDS victims when controlling for prematurity, which is a factor related to chorioamnionitis. An increased incidence of vaginal bleeding (P less than 0.04) and possibly substance abuse or anemia at delivery was found in SIDS mothers. There were more premature and black infants found in the SIDS group compared with the general birth population, and also lower five-minute Apgar scores (P less than 0.02) compared to matched controls. Analysis of the second control group match, including infant Apgar scores, maternal hematocrit, maternal age, and complications of pregnancy and delivery, did not influence any of our conclusions. The data suggests that matching for prematurity may be important in identifying the strength of additional risk factors for SIDS, since the risk factors for SIDS and premature delivery are similar.