The great majority (about 90%) of pregnant women with epilepsy give birth to normal, healthy babies. However, there are increased risks to both mother and child that you need to consider and discuss with your doctor - ideally before conception.
1. Seizures during pregnancy
Most women with epilepsy will have no change in their seizure frequency during pregnancy. Some women have a decrease in seizures and some may even stop having them altogether. About a quarter to a third of women will have increased numbers of seizures during pregnancy, despite continued use of anti-epileptic medication.
Concentrations of seizure medication in your bloodstream may change or decrease during pregnancy, putting you at greater risk for seizures. Your physician will most likely need to check blood levels of your medication more often, and may need to adjust your dose. Some seizure increase, particularly early in pregnancy, may be due to a woman cutting down her anti-epileptic medication, for fear of harming the foetus.
Although many mothers who have seizures have perfectly normal babies, seizures during pregnancy can be dangerous. Seizures can result in falls or lack of oxygen for the mother and thus the baby, and increase the risk of miscarriage and stillbirth.
Status epilepticus (repeated seizures without return to consciousness in between) is potentially fatal for both mother and child: this is why women with epilepsy who find themselves to be unexpectedly pregnant should never suddenly stop medication.
For all the above reasons, it is important to reduce the number of seizures you have during pregnancy by consulting your doctors, taking your medication as prescribed and avoiding likely seizure triggers.
2. Birth defects
Women with epilepsy have a slightly increased risk of having a baby with a birth defect. Women in the general population have about a 2-3% chance of having a baby with a significant birth abnormality; this increases to about 4-8% if the woman has a history of epilepsy.
Severe abnormalities are those that will need treatment after birth or lead to long-term problems for the child. Examples of these are malformations of the spinal cord and spine (spina bifida), malformations of the heart (e.g. hole in the heart), and cleft palate and lip (portions of the mouth do not grow together properly).
Other minor birth defects primarily affect the baby's appearance (so-called "dysmorphic features"). These include facial abnormalities (e.g. eyes set too wide apart or a short upper lip), and small fingers and toes with rudimentary nails. These minor abnormalities do not cause any serious problems, although there is some concern that children born with dysmorphic features may show later evidence of impaired intellectual development.
The increased risk for birth defects may be in part due to anti-seizure medications. However, the current general consensus among medical experts is that the risks associated with having a seizure during pregnancy far outweigh the risk of birth abnormalities. Most women with epilepsy should continue their seizure medication, and whenever possible, take a single anti-epileptic medication at the lowest dose that provides seizure control. Never stop taking your medication or change the dose without the supervision of your doctor. If you haven't had any seizures for two years or more, your doctor may consider it appropriate to try slowly stopping your seizure medication.
You may wish to ask your physician for a referral to a specialist in genetic conditions, who can help in assessing the possible risks. This expert can also recommend tests, such as ultrasound or amniocentesis, which can identify some types of birth defects.
3. Minor complications of pregnancy
Women with epilepsy have a slightly higher risk for minor complications of pregnancy, such as morning sickness, toxaemia (raised blood pressure and protein in the urine) and vaginal bleeding.
4. Other potential problems related to pregnancy
Babies of mothers with epilepsy may have a slightly greater risk of developing seizures, and delays in growth and development.
There is also an increased risk for problems at birth as early or difficult labour, and bleeding.
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(Health24, updated 2009)
Sources: Epilepsy Support Group