Pregnancy Outcomes in Women With Multiple Sclerosis

Abstract

Few studies have assessed the risk of adverse pregnancy outcomes in women with multiple sclerosis (MS). We used 2 large US administrative databases, the Truven Health MarketScan Database (2011-2015; Truven Health Analytics Inc., Ann Arbor, Michigan) and the Nationwide Inpatient Sample (2007-2011), to identify delivery cohorts. MS and pregnancy outcomes (infections, cesarean delivery, preterm delivery, poor fetal growth, preeclampsia, chorioamnionitis, postpartum hemorrhage, stillbirth, and infant malformations) were identified during pregnancy and at delivery. We calculated adjusted risk ratios according to MS status and relapse(s) in the year before delivery. Among over 5 million pregnancies, we identified 3,875 pregnancies in women with MS. Women with MS had an increased risk of infections during pregnancy (Truven Health: adjusted risk ratio (aRR) = 1.22, 95% confidence interval (CI): 1.16, 1.27) and preterm delivery (Truven Health: aRR = 1.19 (95% CI: 1.04, 1.35); Nationwide Inpatient Sample: aRR = 1.30 (95% CI: 1.16, 1.44)). The risks of other outcomes were similar for women with and without MS. In the Truven Health database, risk ratios for the pregnancy outcomes in women experiencing relapses versus those without relapses were between 0.9 and 1.4, and confidence intervals overlapped the null. Overall, women with MS had an increased risk of infections and preterm delivery; however, their risks for other adverse pregnancy outcomes were not elevated. Disease activity before delivery was not a strong predictor of outcomes.

Figure 1.

Sample sizes in a study of pregnancy outcomes among women with multiple sclerosis (MS), United States, 2007–2015. Data were obtained from 2 databases: the Truven Health MarketScan Commercial Claims and Encounters Database (Truven Health Analytics Inc., Ann Arbor, Michigan) (2011–2015) and the Nationwide Inpatient Sample (2007–2011). Pregnancy outcomes included cesarean delivery, preterm delivery, poor fetal growth, preeclampsia, chorioamnionitis, postpartum hemorrhage, and stillbirth. Black dashed arrows indicate the analysis conducted for each sample.

Figure 2.

Risk ratios (RRs) for pregnancy outcomes in women with and without multiple sclerosis, United States, 2007–2015. Data were obtained from 2 databases: the Truven Health MarketScan Commercial Claims and Encounters Database (Truven Health Analytics Inc., Ann Arbor, Michigan) (2011–2015; n = 1,102,604) and the Nationwide Inpatient Sample (NIS) (2007–2011; n = 4,186,816). RRs were adjusted for year, age, region at delivery, and insurance type (NIS only). Infant malformations were assessed in a subcohort of women with continuous enrollment during the 30 days after delivery and a linked infant with continuous enrollment during the 90 days after delivery or evidence of neonatal death (n = 902 women with multiple sclerosis; n = 604,808 women without multiple sclerosis). Bars, 95% confidence intervals (CIs).

Figure 3.

Risk of relapse before and during pregnancy among women with multiple sclerosis in the Truven Health MarketScan Commercial Claims and Encounters Database (Truven Health Analytics Inc., Ann Arbor, Michigan) (2011–2015; n = 1,168). The postpartum trimesters were in the subcohort with continuous enrollment and prescription drug coverage from delivery to 180 days postdelivery (n = 844). Bars, 95% confidence intervals.