Enrollment and Retention in 34 United States Pregnancy Registries Contrasted with the Manufacturer's Capture of Spontaneous Reports for Exposed Pregnancies.

Relatively higher product utilization among pregnant women predicted greater pregnancy registry enrollment. For products rarely used during pregnancy, registry enrollment was low and differences in registry enrollment compared with worldwide spontaneous report receipt were most pronounced. Products with very low utilization levels during pregnancy may require a combination of worldwide pharmacovigilance, pregnancy registries, and additional study methods to achieve adequate surveillance.