Pregnancy and epilepsy
Pregnancy may affect your seizures or the effectiveness of your medication. If you become pregnant without having the chance to have some preconception counselling, it is recommended that you:
- keep taking your anti-epileptic drugs (AEDs) as normal
- ask your doctor to prescribe folic acid supplements of 5mg per day
- make an appointment to see your neurologist as soon as possible.
Could pregnancy affect my epilepsy?
Most women with epilepsy do not have any change in their seizure frequency during pregnancy. However you might find that your seizures are better controlled during pregnancy, or that you have more seizures than is usual for you. This could be because of the common side effects of pregnancy such as tiredness, or the effects of morning sickness on your anti-epileptic drugs (AEDs).
If you are having more seizures while pregnant than you normally do, you can talk to your neurologist about how to manage the situation safely for you and your baby.
Could pregnancy affect my AEDs?
During pregnancy your body may use up more of your AEDs than usual. This means the amount of AED you normally take may not be enough to stop your seizures from happening. This is especially true for the AED lamotrigine.
Although routine monitoring of AED levels in pregnancy is not generally necessary, your neurologist might ask you to have blood tests to make sure that the amount of AED you take is at the right level for you and your baby throughout your pregnancy, especially if your seizures increase or are likely to increase. Testing the levels of the AED in your blood helps your neurologist decide if the dose needs to be changed. If your dose needs to be changed, it will usually be slowly reduced back to its original level after you give birth. However if the higher dose has led to better seizure control after birth, and there is no evidence that this increased dose is causing you problems, then you and your neurologist may decide to leave your AEDs at this new dose.
Can morning sickness affect my AEDs?
Despite the name, morning sickness can happen at any time of the day and affects some women during their first 12 weeks of pregnancy, although it can last longer. If you’re sick after taking your AEDs, the medication may not have a chance to work properly. Changing the time of day you take your AEDs, for example taking them when you’ve stopped feeling sick, may be helpful. However, it is important (as far as possible) to keep the length of time between doses the same. Your doctor should be able to advise you on how best to manage your AEDs.
Can seizures affect an unborn baby?
There is no evidence that the seizure activity in focal aware (previously called simple partial), focal impaired awareness (previously called complex partial), absence or myoclonic seizures are harmful to an unborn baby. However if you injure yourself during any type of seizure, this can carry risks. Tonic clonic seizures could potentially cause miscarriage or serious harm to you and your baby. In rare cases, women with epilepsy have died during pregnancy, mostly due to poor seizure control.
To reduce any risks to you and your baby, the aim is for you to be as seizure-free as possible during your pregnancy. Taking your AEDs as prescribed, and telling your doctors or midwife about any seizures you have, can be helpful.
Can AEDs affect an unborn baby?
If the baby’s father has epilepsy and takes AEDs, these will not affect the baby’s development because the baby will not come into contact with the father's AEDs.
For a woman with epilepsy who takes AEDs during her pregnancy, her baby will be exposed to AEDs in the womb. Although while she is pregnant a mother’s bloodstream is kept separate from her unborn baby’s, some substances can pass from her blood into her baby’s blood via the placenta. These substances include nutrients, oxygen, alcohol and medication, including AEDs. Some AEDs can affect how the baby grows and develops in the womb, particularly so in the first 12 weeks of pregnancy when the baby’s main organs and skeleton are developing.
See more about birth abnormalities and reducing the risk.
What is pre-natal screening?
Pre-natal screening is the name for a number of different checks that all women have done during their pregnancy, to see how their baby is developing in the womb. These include ultrasound scans which are done at certain intervals throughout pregnancy, commonly at 12 weeks (known as the 'dating scan') and at 18 - 20 weeks (known as the 'anomaly scan').
Women are also offered combined blood tests that measure a number of things including alphafetoprotein (AFP) levels. AFP is a type of protein which is passed from an unborn baby to its mother. The levels of AFP in a mother's blood can indicate the risk of their baby being born with certain disorders including spina bifida. Screening does not say for certain if a baby will be born with or without any birth abnormalities. However, it can help to determine the risk of a baby being born with birth abnormalities.
The UK, and Irish, Epilepsy and Pregnancy Registers
If you have epilepsy and are thinking of trying for a baby, or you are already pregnant, you might like to contact The UK, or Irish, Epilepsy Pregnancy Registers. This is a long-term study looking into the effects of AEDs on unborn babies and the effects of having seizures while pregnant.
The study lets you speak to an epilepsy nurse and ask questions about your pregnancy and epilepsy. If you would like to join the register you will be asked about your epilepsy and any AEDs that you take, and the the register may want to contact you after your baby is born. It is free of charge to be part of the study and over 10,000 women have taken part so far.
Research into epilepsy and pregnancy is ongoing. It is hoped that the findings from the study will provide some answers and guidance for other women in the future.
Information produced: April 2021