Principal Scientist Scientific Research and Strategy; Aetion, Inc Boston, United States
Background: Pregnant patients are often excluded from clinical trials, and thus prenatal medication use and subsequent maternal and fetal outcomes are typically captured in postmarketing observational data studies. The Maternal Outcomes Masterset (MOM) is a novel data source comprising closed medical and pharmacy claims from public and private insurance sources.
Objectives: To describe patient characteristics, pregnancy outcomes, and infant outcomes among pregnant patients and their linked infants in the MOM data.
Methods: We identified two cohorts of interest: 1) an overall pregnancy cohort of all patients in the MOM data at first record of pregnancy 1/1/2018 - 12/1/2021 with ≥180 days baseline enrollment, and 2) a live birth subset comprising patients with a live birth in up to 42 weeks of follow-up from first pregnancy claim with continuous enrollment. Among live births, we identified infant linked subgroups, comprising those with infant linkage within 7 days of delivery with ≥90 days infant follow-up, and those without any documented infant linkage. We described maternal patient and pregnancy characteristics and infant characteristics overall and by strata of payer type and infant linkage.
Results: In the overall pregnancy cohort (N=1,438,861), the most common age categories at index were 30-34 (24%) and 25-29 years (23%), and 56% had a recorded race (most commonly White, 25% of all patients). More patients with Medicaid had recorded race compared to commercial coverage (85% vs 28%) and were aged < 30 years (65% vs 44%). The most common pregnancy endpoint recorded was live birth (42%) followed by spontaneous abortion (14%). In the live birth subset (N=602,721), 99% had a gestational age recorded and 35% had at least one linked infant within 90 days after delivery. The subgroups of patients with infant linkage and sufficient follow-up (N=155,621) and patients with no linkage (N=393,220) were generally similar with respect to baseline comorbidities, pregnancy complications, and gestational age at delivery. More patients with linkage vs without had commercial coverage (72% vs 36%), were aged ≥30 years (57% vs 34%), and had unknown race (62% vs 32%). A major congenital malformation was recorded for 4.4% of live births with linkage.
Conclusions: In this first study to describe the large sample of pregnant patients in the MOM data, important risk factors were available for nearly all, and the majority had a recorded pregnancy endpoint. Those with and without infant linkage were similar with respect to pregnancy and delivery characteristics, providing confidence in representativeness of the subgroup with infant linkage.
