Valproate and the pregnancy prevention programme

The NHS states plainly that sodium valproate is not recommended in pregnancy because it can cause birth defects and problems with a child's learning and behaviour. MHRA information describes the risk of neurodevelopmental disorders in children born to mothers taking valproate in pregnancy as up to 30 to 40 per cent, estimated from several studies.

This is why valproate is treated differently from most epilepsy medicines. For women with recurrent migraine, the NHS says doctors should offer an alternative to sodium valproate during pregnancy. Valproate may also be continued in epilepsy or bipolar disorder only if no other suitable treatment exists, which the doctor decides with the patient.

The NHS says that if there is a chance a person could become pregnant while taking sodium valproate, the doctor will enrol them in Prevent, the valproate pregnancy prevention programme. Girls and women who need valproate must be enrolled. The NHS also says treatment must be reviewed every year and tells people who have not had a review to contact their doctor or specialist now.

MHRA safety updates describe the surrounding rules. Treatment for people under 55 should be started only after review by two specialists, a requirement that the Commission on Human Medicines said does not apply to men who are already taking valproate. Valproate-containing medicines must be dispensed in the manufacturer's original full pack except in exceptional circumstances, so patient information and warnings stay with the medicine.

• Enrolment on Prevent for anyone who could become pregnant

• An annual review of treatment

• Review by two specialists before starting if under 55

• Medicine dispensed in the original full pack with its warnings

• Pregnancy planning discussed with a specialist before conception

If you think you might be pregnant while taking sodium valproate, the NHS tells you to contact a doctor or nurse urgently. It also says not to stop taking the medicine without talking to your doctor first, because symptoms could get worse. Missed or delayed periods are also a possible side effect of valproate, so a late period should not simply be put down to the tablets: the NHS says to take a pregnancy test if the period is late and speak to a doctor straight away if it is positive.

Planning ahead is the safest route. A specialist can discuss alternative treatments, how any switch is done safely. If you take other medicines, being sick or having severe diarrhoea can reduce the protection from the contraceptive pill, so the NHS advises checking the pill packet for advice.

In September 2024 the MHRA announced a precaution for men. A retrospective study of records in Norway, Denmark and Sweden found a possible increased risk of neurodevelopmental disorders in children of men treated with valproate in the 3 months before conception, compared with men taking lamotrigine or levetiracetam. The study reported cumulative risks of 4.0 to 5.6 per cent in the valproate group against 2.3 to 3.2 per cent in the comparison group. The MHRA describes the potential risk as much lower than that after exposure through the mother, and notes that a causal role for valproate has not been confirmed, so the advice is precautionary.

The recommended precautions are effective contraception (condoms plus contraception used by the female partner) throughout treatment and for at least 3 months after stopping, not donating sperm during that period, and discussing family plans with the doctor. Men who may be planning a family in the next year should be referred to a specialist to discuss alternatives. Nobody should stop valproate without speaking to a healthcare professional. The NHS also says sodium valproate may reduce fertility in men.

The NHS lists signs that need urgent advice: yellowing of the eyes or skin with dark urine, which may mean liver problems; severe nausea, vomiting or stomach pain, which may mean pancreatitis; and unusual bruising or bleeding, which may mean a blood disorder. Valproate can also change the menstrual cycle and, rarely, has been reported to cause polyendocrine metabolic ovarian syndrome.

These are separate from the pregnancy risks, but they are part of why valproate is monitored closely.

The NHS says that if your baby is healthy you may be able to take valproate while breastfeeding, because it passes into milk in very small amounts. Other treatments may be more suitable, and the doctor decides. Watch for the baby being unusually sleepy, feeding poorly, bruising easily, vomiting or showing jaundice, and seek advice.

Families who took valproate in pregnancy and have concerns about a child's development can ask their GP or health visitor about assessment and support, and can report suspected reactions to the MHRA through the Yellow Card scheme.