CORRELATION OF MATERNAL WEIGHT WITH APPARENT CLEARANCE IN PREGNANCY
Abstract number :
2.326
Submission category :
Year :
2003
Submission ID :
3967
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
William T. Cahill, Oormila P. Kovilam, Jane Khoury Neurology, University of Cincinnati, Cincinnati, OH; Obstetrics and Gynecology, University of Cincinnati, Cincinnati, OH; Environmental Health, University of Cincinnati, Cincinnati, OH
It has been previously shown that AED clearance changes over the course of pregnancy. While several mechanisms have been proposed, the role of maternal weight change is unclear. Given the complexity of caring for women with epilepsy during pregnancy, understanding the impact of maternal weight change on AED clearance would be of interest.
A clinical protocol for the management of women with epilepsy during pregnancy was established at the University of Cincinnati Medical Center in 1991. By March, 2003, two hundred twenty-seven women with epilepsy were treated with an antiepileptic drug during pregancy. Of these, 70 pregnancies were to women treated with carbamazepine and 50 were treated with phenytoin. There were 398 carbamazepine levels and 332 phenytoin levels with corresponding doses available for analysis of apparent clearance. A natural log transformation was used for result and clearance. These clearance values were then correlated with maternal weight. Further analysis included partial correlation adjusting for gestation and initial weight as well as partial correlation adjusting for individual, gestation, and intial weight.
For carbamazepine, there was a weak association (r=0.15; p=0.003) between maternal weight and apparent clearance. There was no correlation (r=0.07; p=0.23) after adjusting for gestation and initial weight. There was no correlation (r=-0.08; p=0.17) after adjusting for individual, gestation, and intial weight. For phenytoin, there was a weak association (r=0.26; p[lt]0.001) between maternal weight and apparent clearance. There was no correlation (r=-0.02; p=0.78) after adjusting for gestation and initial weight. There was no correlation (r=-0.02; p=0.79) after adjusting for individual, gestation, and initial weight.
While there was an association between maternal weight and apparent clearance, there was no significant correlation between maternal weight gain and apparent clearance when adjusted for individual, gestation, and initial weight for either carbamazepine or phenytoin when used in pregnancy. Other mechanisms must be used to explain the apparent clearance changes seen in pregnancy.