The Australian Register of antiepileptic drugs in pregnancy: changes over time in the epileptic population.

The demographic characteristics, details of pregnancies, epilepsies, and treatment of 855 pregnant women with epilepsy enrolled in the Australian Antiepileptic Drugs in Pregnancy Register during 1999-2005 were compared with the corresponding data for the 801 women enrolled from 2006-2012. We estimate that the Register captures approximately 1 in 12 of all pregnancies in Australian women with epilepsy. A number of statistically significant changes were found, with nearly all explained by factors such as re-enrolment of women who had enrolled earlier pregnancies, changes in general population behaviour, altered attitudes to prescribing valproate and using it in lower doses, and the advent of newer antiepileptic drugs which have displaced the use of older agents. It appears that the Register has continued to capture a reasonably representative sample of pregnant Australian women with epilepsy as time has passed.