TABLE 1.

Types of pregnancy exposure registry, and their characteristics

Type of pregnancy exposure registry	Characteristics	Examples (general and COVID)
Clinically led disease‐based pregnancy exposure registries	Recruit pregnant women diagnosed with a specific disease, and can compare outcomes according to the medication or treatment used. Can have high recruitment and retention 1 , 46 . Recruitment may be via disease specialists looking after high risk pregnant women (e.g., neurologists 46 ), or via obstetricians and maternity units. 1 , 48 , 50 , 51 , 52 Recruitment may involve all eligible clinicians 1 and be nearly population‐based, or only clinicians who elect to participate 46 , 50 , 51 . Some systems have been repurposed for COVID‐19 1 , 50 , 51	EURAP (Epilepsy) 46 Obstetric Surveillance Systems 1 , 53 , 54 INTERCOVID based on Intergrowth Study 51 COVIPreg based on Zika pregnancy cohort 50
Teratogen Information Service cohorts.	Teratogen Information Service cohorts are opportunistic cohorts where women who contact the service about a pregnancy exposure, either themselves or via their health professional are enrolled and followed up to ascertain pregnancy outcome. Recruitment may be enhanced for specific studies. 49 The MothertoBaby studies of the OTIS network recruit pregnant women with exposure to medications of interest, with the disease indication, and without these exposures as comparator and are studying COVID‐19 infection, medication and vaccine.	ENTIS 55 (www.entis‐org.eu) OTIS/ MothertoBaby 49 (www.mothertobaby.org)
Industry pregnancy registries.	Industry pregnancy registries are instituted to provide safety data for single medicinal products that may be used by pregnant women. The record of such registries in terms of recruitment of exposed pregnant women, completeness of follow up (attrition), lack of comparator data, and quality of data about congenital anomalies, has been poor. 47 However, for new COVID‐19 medications, industry pregnancy registries are likely to become an important component of the safety monitoring system.	List of Pregnancy Exposure Registries | FDA https://www.fda.gov/science‐research/womens‐health‐research/list‐pregnancy‐exposure‐registries
Direct to mother cohorts.	“Direct to Mother” approaches bypass the healthcare system to recruit pregnant women directly. 56 IRCEP advertises for participants via social media and online parenting forums, 57 following up monthly via an app until 90 days after delivery. PRIORITY uses a partially direct to mother approach, but also recruits pregnant women with confirmed or suspected COVID‐19 via healthcare providers 58 and confirms birth defects with electronic medical records from the hospital of birth. 58	The US‐based International Registry of Coronavirus in Pregnancy (IRCEP) uses the pre‐existing PREGISTRY platform. 57 The US PRIORITY Study (Pregnancy Coronavirus Outcomes Registry) 58
Vaccine safety pregnancy registries recruiting via vaccination centres	Recruitment of pregnant women via vaccination centres rather than via maternity units.	vSafe 43 COVACPREG 59