Severe Maternal Morbidity and the Use of Assisted Reproductive Technology in Massachusetts

OBJECTIVE: To assess whether risk of severe maternal morbidity at delivery differed for women who conceived using assisted reproductive technology (ART), those with indicators of subfertility but no ART ("subfertile"), and those who had neither ART nor subfertility ("fertile"). METHODS: This retrospective cohort study was part of the larger Massachusetts Outcomes Study of Assisted Reproductive Technology. To construct the Massachusetts Outcomes Study of Assisted Reproductive Technology database and identify ART deliveries, we linked ART treatment records to birth certificates and maternal and infant hospitalization records occurring in Massachusetts between 2004 and 2010. An algorithm of International Classification of Diseases, 9th Revision, Clinical Modification diagnosis and procedure codes identified severe maternal morbidity. We used logistic generalized estimating equations to estimate odds of severe maternal morbidity associated with fertility status, adjusting for maternal demographic and health factors and gestational age, stratifying on plurality and method of delivery. RESULTS: The prevalence of severe maternal morbidity among this population (n=458,918) was 1.16%. The overall, crude prevalences of severe maternal morbidity among fertile, subfertile, and ART deliveries were 1.09%, 1.44%, and 3.14%, respectively. The most common indicator of severe maternal morbidity was blood transfusion. In multivariable analyses, among singletons, ART was associated with increased odds of severe maternal morbidity compared with both fertile (vaginal: adjusted odds ratio [OR] 2.27, 95% confidence interval [CI] 1.78-2.88; cesarean: adjusted OR 1.67, 95% CI 1.40-1.98, respectively) and subfertile (vaginal: adjusted OR 1.97, 95% CI 1.30-3.00; cesarean: adjusted OR 1.75, 95% CI 1.30-2.35, respectively) deliveries. Among twins, only cesarean ART deliveries had significantly greater severe maternal morbidity compared with cesarean fertile deliveries (adjusted OR 1.48, 95% CI 1.14-1.93). CONCLUSION: Women who conceive through ART may have elevated risk of severe maternal morbidity at delivery, largely indicated by blood transfusion, even when compared with a subfertile population. Further research should elucidate mechanisms underlying this risk.