Coitus late in pregnancy: risk of preterm rupture of amniotic sac membranes.

OBJECTIVES: Coitus with or without orgasm in late pregnancy is inconsistently associated with preterm rupture of amniotic sac membranes. We tested the hypothesis that during late pregnancy sexual behaviors including sexual positioning relate to the occurrence of premature rupture of membranes.

STUDY DESIGN: Women aged 15 to 45 years having preterm premature rupture of membranes, term premature rupture of membranes, or preterm delivery without premature rupture of membranes were matched singly by age, race, and parity to control women delivered of term infants. Information about six sexual activities, obstetric history, cervical infections, smoking during pregnancy, and sociodemographic information was obtained by face-to-face interview.

RESULTS: Only the male superior position was significantly associated with preterm premature rupture of membranes (odds ratio 2.40, 95% confidence interval 1.16 to 4.97) and preterm delivery without premature rupture of membranes (odds ratio 1.82, confidence interval 1.02 to 3.25) after confounding variables were controlled for. No sexual positioning or sexual activities related significantly to term premature rupture of membranes.

CONCLUSION: Most sexual positions and activities during late pregnancy are not associated with adverse pregnancy outcomes.