The drug lamotrigine, which is typically prescribed for seizures, is not proven safe for use during pregnancy. One worrisome fact involves animal studies, which have revealed that this drug can cause harm to animal fetuses. The drug has also been linked to the development of cleft lip and cleft palate, which are oral birth defects, in the babies of women who have taken it during pregnancy. It is important to note that there is no definite proof that lamotrigine is harmful during human pregnancy, as the drug hasn't been tested in human pregnancy trials. Due to the potential for cleft defects and the results of animal trials, however, many health experts agree that it probably represents a risk, and doctors will often only prescribe it to pregnant women when the benefits of taking the medication are likely to outweigh the risk it represents.
Though there is some evidence of risk in taking lamotrigine in pregnancy, cleft defect reports seem to point to only a slight risk. Some studies show that less than 10 percent of every 1,000 pregnant women who have taken the drug report this type of defect. Animal studies, however, have resulted in such serious problems as toxicity in the pregnant female and the fetus, lower-than-normal fetal weight, impaired bone formation, and sometimes even death of the unborn animal.
In the event that a doctor and his patient decide that current lamotrigine use should continue during pregnancy, dose adjustments may prove helpful for lowering risk levels. In such a case, a doctor may evaluate a patient's health and lower her dosage as much as possible. After adjusting the medicine to the lowest possible dosage, a doctor may then monitor the levels of the medication in the woman's blood in order to ensure that they remain adequate. As a woman's pregnancy progresses and she experiences bodily changes, a doctor may decide to further adjust her use of lamotrigine in pregnancy.
In addition to not recommending the use of lamotrigine in pregnancy, health experts often recommend against its use during breastfeeding as well. This is due to the fact that the medication is known to pass into breast milk. In some instances, breastfed babies have developed mild cases of a condition called thrombocytosis, which is marked by an abnormally high number of platelets in the patient's blood, when their mothers were taking lamotrigine. As with prescribing lamotrigine in pregnancy, many doctors consider whether the benefits outweigh the risks when prescribing it for breastfeeding mothers.