Trends in Severe Maternal Morbidity After Assisted Reproductive Technology in the United States, 2008-2012

The use of assisted reproductive technology (ART) has doubled over the past decade. In 2013, 1.5% of all neonates in the United States were conceived after ART. Severe maternal morbidity has been increasing in the United States since 1998 and currently affects more than 60,000 women every year. With the growing number of pregnancies conceived with ART, there may be an increased risk of severe maternal morbidity in this potentially high-risk population comparedwith pregnancies conceived without ART. The aim of this retrospective cohort study was to compare rates of severe maternal morbidity during delivery and postpartum hospitalizations in single and multiple gestation pregnancies conceived using ART with rates among pregnancies conceived without ART. The Truven Health Market-Scan Commercial Claims and Encounters Databases were used to identify deliveries occurring between 2008 and 2012. All women 15 years or older who had a delivery hospitalization during the 4-year study period were identified using International Classification of Diseases, 9th Revision, Clinical Modification diagnosis codes and Current Procedural Terminology codes. Rates of having at least 1 severe maternal morbidity indicator per 10,000 deliveries were calculated for ART and non-ART pregnancies. Multivariable logistic regression was performed, controlling for maternal characteristics to determine which patient factors were associated with severe morbidity. To supplement these data, a propensity score analysis was performed between ART and non-ART deliveries. Singleton and multiple deliveries were analyzed separately for both logistic regression and propensity score analyses. Between 2008 and 2012, 1,016,618 deliveries were identified; 14,761 (1.5%) of these were pregnancies conceived with ART. The most common severe morbidity indicator for ART and non-ART pregnancies was blood transfusion. For every 10,000 singleton pregnancies, 273 ART deliveries or postpartum hospitalizations were associated with at least 1 with severe maternal morbidity indicator compared with 126 for non-ART pregnancies (P < 0.001). Linear regression analysis showed that the rate of severe maternal morbidity for ART singletons deliveries decreased from 369 per 10,000 deliveries in 2008 to 219 per 10,000 deliveries in 2012 (P = 0.025). After controlling for age, parity, comorbid conditions, prior cesarean delivery, and year of delivery, ARTsingletons had significantly higher odds of severematernalmorbidity compared with non-ART singletons; the adjusted odds ratio (aOR) was 1.84, with a 95% confidence interval of 1.63 to 2.08. For multiple gestations, no significant difference between ART and non-ART pregnancies was found (rate of severe morbidity for ART 604/10,000 vs non-ART 539/10,000 deliveries [aOR, 1.04; 95% confidence interval, 0.91-1.20; P = 0.089]). Assisted reproductive technology remained significantly associated with severe maternal morbidity after propensity score matching. These findings show that the risk of severe maternal morbidity is significantly higher for singleton pregnancies conceived with ARTcompared with non-ARTsingletons; the risk rates, however, have been decreasing since 2008. The risk is higher for multiple pregnancies regardless of ART status.