Hernandez–Diaz S, et al. – Physicians designed this study to assess the effects of epilepsy and antiepileptic drugs (AED) use during pregnancy on fetal growth and preterm delivery. During pregnancy, women on AEDs were at a higher risk of delivering prematurely and giving birth to small–for–gestational–age (SGA) newborns whether for epilepsy or for other neuropsychiatric indications. The risk could vary by drug.

• Singleton liveborns born to women enrolled in the North American Antiepileptic Drug Pregnancy Registry between 1997 and 2016, were included in this study.
• Through telephone interviews, data were collected prospectively.
• The physicians compared the prevalence of preterm birth (<37 weeks) and small-for-gestational-age (SGA) among infants exposed prenatally to AED when used by women with epilepsy (WWE) or women without epilepsy (WWOE) with that among infants unexposed to AEDs and born to WWOE.
• They used multivariable log-binomial regression models to estimate relative risks (RR) and 95% confidence intervals (CI).

• The physicians included infants born to 6,777 AED-WWE, 696 AED-WWOE, and 486 no-AED WWOE.
• For no-AED-WWOE, the risk of prematurity was 6.2%, 9.3% for AED-WWE (RR 1.5, 95%CI: 1.0-2.1) and 10.5% for AED-WWOE (RR 1.5: 1.0-2.4).
• As compared to no-AED WWOE, prenatal exposure to AED in WWE and WWOE was correlated with a mean lower birth weight of 110 and 136 grams, respectively.
• For no-AED-WWOE, the prevalence of SGA was 5.0%, 10.9% for AED-WWE (RR 2.0: 1.3-3.0) and 11.0% for AED-WWOE (RR 1.9: 1.2-2.9).
• The prevalence of SGA ranged from 7.3% for lamotrigine to 18.5% for topiramate within users of AEDs in monotherapy.