Publications by authors named "Caitlin R Smith"

3 Publications

  • Page 1 of 1

Association between topiramate and zonisamide use during pregnancy and low birth weight.

Obstet Gynecol 2014 Jan;123(1):21-28

Department of Epidemiology, Harvard School of Public Health, and North American Antiepileptic Drug Pregnancy Registry, Massachusetts General Hospital for Children, Boston, Massachusetts; Loyola University Health System, Chicago, Illinois; the College of Physicians and Surgeons and Mailman School of Public Health, Columbia University, New York, New York; and Oregon Health and Science University, Portland, Oregon.

Objective: To assess the possible effects of topiramate and zonisamide use during pregnancy on fetal growth.

Methods: The study population was the singleton liveborns born to women who enrolled in the North American Antiepileptic Drug Pregnancy Registry between 1997 and 2012. Data were collected through telephone interviews at enrollment, 7 months of gestation, and postpartum. The prevalence of small for gestational age at birth among neonates exposed to topiramate and to zonisamide when either was used as monotherapy during pregnancy was compared with that among neonates exposed to lamotrigine monotherapy, a weight-neutral therapy, and the most common antiepileptic drug in the Registry. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated with multivariable log-binomial regression to control for potential confounders.

Results: Data were available for 347 topiramate, 98 zonisamide, and 1,581 lamotrigine-exposed neonates. The mean gestational length was 39 weeks for all comparison groups. Prenatal exposure to topiramate or zonisamide was associated with a mean lower birth weight of 221 and 202 g, respectively, and a mean lesser neonatal length of 1 cm as compared with lamotrigine exposure (p<.01). The prevalence of small for gestational age was 6.8% for lamotrigine, 17.9% for topiramate (RR 2.4, 95% CI 1.8-3.3) and 12.2% for zonisamide (RR 1.6, 0.9-2.8). Similar results were found when a group of 457 unexposed neonates was used as the reference.

Conclusions: Topiramate and zonisamide have been shown to reduce weight in adults. Our finding of a decrease in mean birth weight and length among neonates exposed in utero raises concern.

Level Of Evidence: II.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
January 2014

Fetal effects of anticonvulsant polytherapies: different risks from different drug combinations.

Arch Neurol 2011 Oct 13;68(10):1275-81. Epub 2011 Jun 13.

North American AED Pregnancy Registry, Genetics Unit, MassGeneral Hospital for Children, Boston, MA 02114, USA.

Objective: To determine the frequency of malformations among infants born to women who had taken lamotrigine or carbamazepine as part of polytherapy during the first trimester of pregnancy.

Design: A cohort of women enrolled during pregnancy in the North American AED (Antiepileptic Drug) Pregnancy Registry between February 1, 1997, and June 1, 2010. Information on AED use and demographic characteristics was collected in 3 telephone interviews.

Setting: United States and Canada.

Patients: A total of 6857 pregnant women taking an AED for any reason.

Main Outcome Measures: Major congenital malformations were identified at birth and through the first 12 weeks after delivery. Diagnoses were based on the mother's report and confirmed by medical records. The risks of malformations were compared between polytherapy and monotherapy groups, using exact odds ratios (ORs) and 95% confidence intervals (CIs).

Results: The risk of malformations was 1.9% among infants exposed to lamotrigine as monotherapy (n = 1441). Among the infants exposed to lamotrigine as polytherapy (n = 505), the risks were 9.1% for lamotrigine plus valproate sodium (OR, 5.0; 95% CI, 1.5-14.0) and 2.9% for lamotrigine plus any other AEDs (1.5; 0.7-3.0). The risk of malformations was 2.9% for the infants exposed to carbamazepine monotherapy (n = 1012). For the infants exposed to carbamazepine as polytherapy (n = 365), the risks were 15.4% for carbamazepine plus valproate (OR, 6.2; 95% CI, 2.0-16.5) and 2.5% for carbamazepine plus any other AEDs (0.8; 0.3-1.9). Confounding by factors such as periconceptional vitamin use, cigarette smoking, alcohol use, and chronic maternal diseases did not explain the results.

Conclusions: The risk of malformations among infants exposed to lamotrigine and carbamazepine as polytherapy was higher than the corresponding monotherapies only when the polytherapy includes valproate. These findings suggest that counseling for fetal risks from AED polytherapy should be based on the specific drugs included.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
October 2011

Valproate teratogenicity and epilepsy syndrome.

Epilepsia 2008 Dec 13;49(12):2122-4. Epub 2008 Jun 13.

Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.

Maternal valproate (VPA) use is associated with a significant risk for congenital malformations in the exposed fetus. Since VPA is commonly used in epilepsy syndromes with a presumed genetic cause (idiopathic epilepsies), it is possible that maternal genetic background contributes to this outcome. We reviewed responses to telephone questionnaires and medical records, when available, of enrollees in the North American Antiepileptic Drug Pregnancy Registry, classifying reason for treatment as idiopathic generalized epilepsy (IGE), partial epilepsy (PE), nonclassifiable epilepsy (NCE), or not epilepsy (NE). Of 284 VPA-exposed pregnancies, 30 (11.0%) were associated with malformations: IGE = 15/126 (12%), PE = 4/28 (14%), NCE = 9/105 (9%), NE = 2/25 (8%) (p > 0.7 for all comparisons). There was a trend toward increased malformation risk with higher VPA doses (p = 0.07). VPA, and not the underlying genetic syndrome, seems to be associated with the elevated risk for malformations in the drug-exposed fetus.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
December 2008