MATERNAL SMOKING AND THE RISK OF POLYHYDRAMNIOS

Background. Washington State birth certificates were used to conduct a population-based case-control study to assess the possible associatio n of maternal smoking with polyhydramnios. Methods. All singleton birt hs complicated by polyhydramnios (n = 557) were identified from the vi tal records for the years 1984 to 1987. For comparison, 1671 records w ere randomly selected for the same years from singleton births uncompl icated by polyhydramnios. Results. Women who reportedly smoked prenata lly were found to be at increased risk for polyhydraminos (relative ri sk [RR] = 1.7, 95% confidence interval [CI] = 1.5-2.1, adjusted for ma rital status, maternal age, and parity). When women with conditions kn own to be associated with polyhydramnios were excluded, the risk for t hose who smoked prenatally remained elevated (RR = 1.8, 95% CI = 1.1-2 .3). Conclusion. Overdistention of the uterus from polyhydramnios may cause a variety of pregnancy complications. The observed association o f smoking with polyhydramnios may be a further indication for public h ealth interventions aimed at preventing smoking during pregnancy.