Both Sanofi and campaigners have advised women taking sodium valproate, not to stop anti-epileptic medications suddenly, without discussing their treatment with their doctor.
Half were given antiepileptic drugs carbamazepine or valproate immediately, while the other half did not receive any treatment until they and their clinician agreed it was necessary.
Families involved in last year's legal action had claimed Epilim, or sodium valproate, caused a range of birth defects which they said included spina bifida, heart damage, learning difficulties and cleft palate.
The drug's manufacturers, Sanofi, said valproate may be the only medication that effectively controls seizures for some women and to suddenly stop taking any anti-epileptic medication could lead to a recurrence of seizures.