Barrier methods, length of preconception intercourse, and preeclampsia.

Background: The immune maladaptation theory suggests that tolerance to paternal antigens, resulting from prolonged exposure to sperm, protects against the development of preeclampsia. We tested whether barrier contraception and shorter sexual experience with the father of the pregnancy would increase the risk of preeclampsia.

Methods: Of 2211 women delivering singleton births after enrollment in a pregnancy cohort study, 85 (3.8%) developed preeclampsia as defined by antepartum systolic blood pressure > or = 140 or diastolic blood pressure > or = 90 plus proteinuria. At a mean of 10.2 weeks of gestation, all women in the cohort were asked about preconception contraception and timing of first sexual intercourse with the father of the pregnancy. Odds ratios (OR) comparing cases with preeclampsia to the rest of the cohort were adjusted for age, smoking, parity, and body mass index (BMI).

Results: Women using barrier contraception prior to conception were no more likely than women not using barrier contraception to develop preeclampsia (adjusted OR 1.0, 95% CI 0.6-1.6). In unadjusted analyses, a prolonged time to conception was associated with preeclampsia (OR 1.9), however, after adjustment, the association was less prominent (OR 1.6) and after stratification by contraception method, the link between time to conception and preeclampsia was eliminated.

Conclusion: These data do not support the immune maladaptation theory of preeclampsia.