Epilepsy
Contraception and pregnancy

Women of child-bearing age, including those with epilepsy, are at risk of unintended pregnancies if they are not using an effective form of contraception. Women with epilepsy may experience a temporary increase in seizure frequency when they begin hormonal contraception.

Some anti-seizure medications interact with enzymes in the liver and cause the drugs in hormonal contraception to be broken down more quickly. These enzyme inducing drugs make hormonal contraception less effective, and this is particularly hazardous if the anti-seizure medication is associated with birth defects. Potent enzyme-inducing anti-seizure medications include carbamazepine, eslicarbazepine acetate, oxcarbazepine, phenobarbital, phenytoin, primidone, and rufinamide. The drugs perampanel and topiramate can be enzyme-inducing at higher doses. Conversely, hormonal contraception can lower the amount of the anti-seizure medication lamotrigine circulating in the body, making it less effective. The failure rate of oral contraceptives, when used correctly, is 1%, but this increases to between 3–6% in women with epilepsy. Overall, intrauterine devices (IUDs) are preferred for women with epilepsy who are not intending to become pregnant.

Women with epilepsy, especially if they have other medical conditions, may have a slightly lower, but still high, chance of becoming pregnant. Women with infertility have about the same chance of success with in vitro fertilisation or other forms of assisted reproductive technology as women without epilepsy. There may be a higher risk of pregnancy loss.

Once pregnant, there are two main concerns related to pregnancy. The first concern is about the risk of seizures during pregnancy, and the second concern is that the anti-seizure medications may result in birth defects. Most women with epilepsy must continue treatment with anti-seizure drugs, and the treatment goal is to balance the need to prevent seizures with the need to prevent drug-induced birth defects.

Pregnancy does not seem to change seizure frequency very much. When seizures happen, however, they can cause some pregnancy complications, such as pre-term births or the babies being smaller than usual when they are born.

All pregnancies have a risk of birth defects, e.g., due to smoking during pregnancy. In addition to this typical level of risk, some anti-seizure drugs significantly increase the risk of birth defects and intrauterine growth restriction, as well as developmental, neurocognitive, and behavioral disorders. Most women with epilepsy receive safe and effective treatment and have typical, healthy children. The highest risks are associated with specific anti-seizure drugs, such as valproic acid and carbamazepine, and with higher doses. Folic acid supplementation, such as through prenatal vitamins, reduced the risk. Planning pregnancies in advance gives women with epilepsy an opportunity to switch to a lower-risk treatment program and reduced drug doses.

Although anti-seizure drugs can be found in breast milk, women with epilepsy can breastfeed their babies, and the benefits usually outweigh the risks.
oulipo:avoid_letter[e]