Increased incidence of gestational hypertension and preeclampsia after assisted reproductive technology treatment

Objective To determine the association between assisted reproductive technology (ART) treatment and the rate of combined gestational hypertension (GH), preeclampsia (PE). Design Retrospective population study. Setting Not applicable. Patient(s) A total of 596,520 mothers (3.6% ART mothers) who gave birth between 2007 and 2011. Intervention(s) Not applicable. Main Outcome Measure(s) Comparison of the rate of GH/PE for ART and non-ART mothers, with odds ratio (OR), adjusted odds ratio (AOR), and 95% confidence interval (CI) used to assess the association between ART and GH/PE. Result(s) The overall rate of GH/PE was 4.3%, with 6.4% for ART mothers and 4.3% for non-ART mothers. The rate of GH/PE was higher for mothers of twins than singletons (12.4% vs. 5.7% for ART mothers; 8.6% vs. 4.2% for non-ART mothers). The ART mothers had a 17% increased odds of GH/PE compared with the non-ART mothers (AOR 1.17; 95% CI, 1.10-1.24). After stratification by plurality, the difference in GH/PE rates between ART and non-ART mothers was not statistically significant, with AOR 1.05 (95% CI, 0.98-1.12) for mothers of singletons and AOR 1.10 (95% CI, 0.94-1.30) for mothers of twins. Conclusion(s) The changes in AOR after stratification indicated that multiple pregnancies after ART are the single most likely explanation for the increased rate of GH/PE among ART mothers. The lower rate of GH/PE among mothers of singletons compared with mothers of twins suggests that a policy to minimize multiple pregnancies after ART may reduce the excess risk of GH/PE due to ART treatment.