BRECKENRIDGE, COLO. — A strong case can be made for encouraging a few weeks or months of breast-feeding by epileptic women who have heeded neurologic advice to continue their seizure medication throughout pregnancy, Jose E. Cavazos, M.D., said at a conference on epilepsy syndromes sponsored by the University of Texas at San Antonio.
In addition to all the usual benefits of breast-feeding, such as enhanced maternal-infant bonding, this practice greatly reduces the likelihood of neonatal antiepileptic drug (AED) withdrawal syndrome, said Dr. Cavazos, a neurologist at the university's South Texas Comprehensive Epilepsy Center.
Transplacental passage of AEDs occurs readily. Studies have shown maternal serum and umbilical cord blood concentrations of AEDs are generally similar. After being exposed to therapeutic AED concentrations throughout fetal life, a baby who experiences abrupt postpartum discontinuation often develops a withdrawal syndrome marked by increased irritability.
This can be avoided by taking advantage of the fact that most AEDs enter breast milk in concentrations similar to those found in maternal serum.
“Many women have an irrational attitude of 'I don't want to give my baby this medicine.' I tell such a patient that for the last 9 months, her baby has been exposed to an AED. I suggest breast-feeding for the first several weeks, then weaning from the breast and, in that way, gradually weaning the baby off the medication. When it's presented in that light, it's more often that breast-feeding will occur,” the neurologist explained.
There is little downside to such an approach, he added. Idiosyncratic drug reactions are extremely unlikely in a neonate exposed in utero. There have been no large prospective studies of the neurodevelopmental impact of breast-feeding by mothers on AEDs, although several studies suggest in utero exposure is associated with mild, partially reversible delays in motor coordination.
Breast-feeding while the mother is on an AED can result in neonatal sedation, but it's typically mild and of little concern unless the mother is taking large doses of phenobarbital.
And speaking of phenobarbital, some obstetricians still favor it for seizure control in pregnancy, although the practice is no longer recommended. “In fact, in the past year, I've had two women who were switched from other AEDs to phenobarbital because they became pregnant and happened to visit their ob.gyns. before seeing their neurologists.
“This is not necessarily the best way to go,” Dr. Cavazos noted during his presentation.
A recent report from the North American AED Registry is instructive. Of 77 pregnancies exposed to phenobarbital monotherapy from conception and followed prospectively, 5 (6.5%) resulted in major malformations identified by 5 days of age. This represented a 4.2-fold elevation over the background risk (Arch. Neurol. 2004;61:673–8).