Spontaneous preterm birth: a case-control study

Approximately 9 percent of single live births in the US occur prematurely, of which two thirds occur spontaneously. Premature infants are at increased risk for neonatal diseases and death. This study examined risk factors associated with spontaneous premature births. A number of characteristics of 140 women who gave birth prematurely and spontaneously were compared with those of 140 women, matched for age and date of delivery, who gave birth spontaneously at term. More of the women who gave birth prematurely were nonwhite, single, and had completed less than 12 years of schooling. When these demographic variables were controlled for, women who had a history of induced abortion were slightly more likely to deliver prematurely. Women who had previously delivered prematurely were significantly more likely to have delivered prematurely in this group of deliveries. Smoking was also associated with an increased risk for delivering prematurely. Even when smoking was controlled for, women who were underweight were more likely to deliver prematurely. Maternal exposure to diethylstilbestrol (DES) was also associated with an increased risk for delivering prematurely. The results indicated a number of factors associated with an increased risk of delivering prematurely. (Consumer Summary produced by Reliance Medical Information, Inc.)