Registries can be used to provide an early warning system for potential ter
atogenic effects associated with the use of specific medications during pre
gnancy. Glaxo Wellcome has developed 5 international registries: (1) the Ac
yclovir Pregnancy Registry, (2) the Antiretroviral Pregnancy Registry, (3)
the Lamotrigine Pregnancy Registry, (4) the Sumatriptan Pregnancy Registry,
and (5) the Bupropion Pregnancy Registry. The purpose of these registries
is to gain more information about the potential teratogenicity of these dru
gs during pregnancy, Two potential limitations of such registry data are re
cognized: (1) the utility of the data collected depends on the size of the
sample; and (2) the registered patients may not be representative of all pa
tients using the medication. However, these types of registry reports can b
e a valuable and cost-effective way to collect data regarding the use of me
dications during pregnancy when conventional methods (eg, cohort studies) a
re not appropriate or feasible.