OBJECTIVE: Data on seizure and pregnancy outcomes in Asian women with epilepsy are limited. We used a Chinese pregnancy registry to assess the impact of seizures and antiseizure medications (ASMs) on pregnant women with epilepsy and their children. METHODS: This is an ongoing prospective multicenter study of pregnant women with epilepsy that has been running since 2012. Eligible participants were consecutively enrolled and had multiple follow-ups up to one year after delivery. We assessed ASM use and seizure frequency during pregnancy to establish potential effects on the mothers and infants and to identify relevant correlations. Descriptive analysis was used to estimate proportions. Logistic regression was used to identify the relevant risk factors and correlations. RESULTS: Of 1907 potentially eligible pregnancies, we included 1763 in 1483 women with known outcomes from January 2012 to February 2022. There were 1278 completed pregnancies, resulting in 1270 live births. Tonic-clonic seizures occurred in fewer than one-third of pregnancies in each trimester. Compared with baseline, seizure frequency remained relatively stable throughout approximately two-thirds of the pregnancies. The majority were on ASM, with levetiracetam (39%), oxcarbazepine (19%), and lamotrigine (17.5%) being the most commonly used. In contrast, only 14.2% of pregnancies were exposed to valproate (VPA). There was a declining trend in treatment adjustments over the course of the pregnancy, with most changes occurring in the first trimester. The incidence of major congenital malformation (MCM) was 4.4%, with cardiogenic and orofacial anomalies being the most common. VPA use (p <
.001), lack of folic acid use (p = .009), positive family history of MCM (p = .006), and topiramate (TPM) use (p = .04) were the most important predictors of MCM. SIGNIFICANCE: Seizure control remained stable for the majority of women with epilepsy throughout pregnancy. Family history of MCM, VPA use, TPM use, and not taking folic acid were strong predictors of MCM in infants born to women with epilepsy.