(210) Demographic Representativeness of Participants in Pregnancy Registries

Publication Number: 541

Background: Given the documented disparities in pregnancy outcomes based on race, ethnicity, age, and socio-economic factors, ensuring the representativeness of pregnancy registry participants is essential to evaluate risk of adverse pregnancy outcomes and to ensure generalizability. Yet, it can be a challenge for voluntary, observational studies like pregnancy registries to ensure the study population is representative in terms of potential biological, social, and other determinants of health. Understanding the demographic characteristics of pregnancy registry participants is important for assessing representativeness and putting results into context.

Objectives: To examine the demographic characteristics of pregnancy registry participants in the published literature in comparison with those of pregnant women in the general US population.

Methods: We searched PubMed (term “pregnancy registry”) and the websites of OTIS, VAMPSS, and Antiretroviral Pregnancy Registry (APR) to identify English language publications from pregnancy registries conducted primarily in the US and Europe. The most recent publication from each registry that reported the impact of drug exposures on pregnancy outcomes was included. Demographic data on age, race, ethnicity, and maternal education were extracted, summarized with descriptive statistics, and compared with 2020 US births data from CDC Wonder.

Results: Of the 394 publications identified via our searches, 37 met inclusion criteria. Most publications (27/37; 73.0%) reported at least one demographic characteristic: 26/27 reported age, 17/27 reported race, 11/27 reported ethnicity, and 9/27 reported maternal education. Mean age of registry participants was similar to that of pregnant women in the general US population (28.1 years vs. 29.2 years); however, the proportions of registry participants who were white (82.4% excluding APR vs 73.3%), non-Hispanic or Latino (83.6% vs. 75.1%), or college educated (70.6% vs. 60.7%) were higher than those of pregnant women in the US.

Conclusions: Most pregnancy registry participants are white, non-Hispanic, and college educated; racial and ethnic minorities and those who did not attend college are underrepresented. Innovative study designs, engagement plans, and operational strategies to engage these populations should be prioritized.