American AED (antiepileptic drug) Pregnancy Registry was established
in 1997 for pregnant women in the United States and Canada at the Massachusetts
General Hospital in Boston, Massachusetts. It was established with funds
provided by six companies that manufacture "old" and "new"
anticonvulsant drugs. The major objective is to obtain and publish
information on the frequency of major malformations, such as heart defects,
spina bifida and cleft lip, among infants whose mothers had taken one
or more AEDs to prevent seizures or to treat any other medical condition.
The highest priority was new information on the many "new" AEDs
marketed in the past 10 years.
We hope that
this method of evaluating drugs will determine which anticonvulsant drugs
appear to be safer to use in pregnancy. To do this we need the cooperation
of many more eligible women and their health care providers.
We are very grateful to the 8,500 women who have enrolled
as of April 2012.
for release of results for a positive association (relative risk, >1)
is met when the lower of the 95% confidence interval (CI) is greater than
or equal to 2.0. The release criterion for no associated increase in the
frequency of all major malformations is met when the upper of the 95%
confidence limits does not exceed 2.0. The external comparison group is
the findings in the Active Malformations Surveillance Program at Brigham
and Women's Hospital. The findings in 69,277 newborns was a baseline rate
of 2.24%, which was reduced to 1.62% after excluding infants with genetic
disorders and chromosome abnormalities. The major malformations are identified
between birth and age 5 days. The inclusion/exclusion criteria are the
same as those used in the AED Pregnancy Registry.