Maternal Antibodies to Chlamydia trachomatis and Risk of Gastroschisis

Background: Gastroschisis, a birth defect of the abdominal wall, is increasing in prevalence. The largest increase in prevalence has been observed among young mothers (< 20 years). The prevalence of Chlamydia trachomatis (CT) infection is highest among young women and has also been increasing over time. The objective was to investigate the association between immunoglobulin G antibodies to Chlamydia trachomatis (CT) (anti-CT) and Chlamydial heat shock protein 60 (anti-CHP60) during pregnancy, and risk of gastroschisis among offspring. Methods: We conducted a nested case-control study of 292 gastroschisis cases identified from the Congenital Malformations Register and 826 live born controls matched on age and birth year within the Finnish Maternity Cohort. Early pregnancy serum samples were used to categorize women by seropositivity to anti-CT and anti-CHP60. Women seronegative for anti-CT and anti-CHP60 served as the reference. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Effect measure modification by maternal age (< 25 years, >= 25 years) was also assessed. Results: Seropositivity to anti-CT (17.8% of cases vs. 16.0% of controls) or anti-CHP60 (23.6% of cases vs. 22.0% of controls) was not associated with gastroschisis. Although, the OR for seropositivity to anti-CT alone was slightly elevated (OR, 1.19; 95% CI, 0.73-1.94), specifically among young mothers (< 25 years) (OR, 1.65; 95% CI, 0.81-3.37), the results were imprecise. Conclusion: Chlamydia infection, as measured by immunoglobulin G antibodies to CT and CHP60, is not associated with gastroschisis, however, our assays were not able to distinguish recent infection. (C) 2017 Wiley Periodicals, Inc.