Medicines related to valproate: risk of abnormal pregnancy outcomes
Children exposed in utero to valproate are at a high risk of serious developmental disorders (in up to 30-40% of cases) and/or congenital malformations (in approximately 10% of cases).
Post publication note: this article has been superseded. Valproate medicines are contraindicated in women and girls of childbearing potential unless conditions of Pregnancy Prevention Programme are met. See Drug Safety Update April 2018 for more information.
New measures have been implemented to reduce the harms of valproate treatment, including new safety and educational materials. See Drug Safety Update January 2024 for more information and the valproate guidance page for safety and educational materials.
This is to inform you of important new information and strengthened warnings related to safety of medicines related to valproate (sodium valproate, valproic acid [brand leader: Epilim] and valproate semisodium [brand leader: Depakote]), following completion of a Europe-wide review:
- children exposed in utero to valproate are at a high risk of serious developmental disorders (in up to 30-40% of cases) and/or congenital malformations (in approximately 10% of cases)
- valproate should not be prescribed to female children, female adolescents, women of childbearing potential or pregnant women unless other treatments are ineffective or not tolerated
- valproate treatment must be started and supervised by a doctor experienced in managing epilepsy or bipolar disorder
- carefully balance the benefits of valproate treatment against the risks when prescribing valproate for the first time, at routine treatment reviews, when a female child reaches puberty and when a woman plans a pregnancy or becomes pregnant
- you must ensure that all female patients are informed of and understand:
- risks associated with valproate during pregnancy
- need to use effective contraception
- need for regular review of treatment
- the need to rapidly consult if she is planning a pregnancy or becomes pregnant
Please refer to the General Medical Council’s consent and prescribing guidance.
Risk of abnormal pregnancy outcomes
Valproate is associated with a dose-dependent risk of abnormal pregnancy outcomes, whether taken alone or in combination with other medicines. Data suggest that when valproate is taken for epilepsy with other medicines, the risk of abnormal pregnancy outcomes is greater than when valproate is taken alone.
The risk of congenital malformations is approximately 10 % while studies in preschool children exposed in utero to valproate show that up to 30-40% experience delays in their early development such as talking, and/or walking, have low intellectual abilities, poor language skills and memory problems.[footnote 1] [footnote 2] [footnote 3] [footnote 4] [footnote 5]
Intelligence quotient (IQ) measured in a study of 6 years old children with a history of valproate exposure in utero was on average 7-10 points lower than those children exposed to other antiepileptics.[footnote 6]
Available data show that children exposed to valproate in utero are at increased risk of autistic spectrum disorder (approximately three-fold) and childhood autism (approximately five-fold) compared with the general study population Limited data suggests that children exposed to valproate in utero may be more likely to develop symptoms of attention deficit/hyperactivity disorder (ADHD). [footnote 7] [footnote 8] [footnote 9]
Given these risks, valproate for the treatment of epilepsy or bipolar disorder should not be used during pregnancy and in women of child-bearing potential unless clearly necessary ie in situations where other treatments are ineffective or not tolerated.
Carefully balance the benefits of valproate treatment against the risks when prescribing valproate for the first time, at routine treatment reviews, when a female child reaches puberty and when a woman plans a pregnancy or becomes pregnant.
If you decide to prescribe valproate to a woman of child-bearing potential, she must use effective contraception during treatment and be fully informed of the risks for the unborn child if she becomes pregnant during treatment with valproate.
Treatment during pregnancy
If a woman with epilepsy or bipolar disorder who is treated with valproate plans a pregnancy or becomes pregnant, consideration should be given to alternative treatments.
If valproate treatment is continued during the pregnancy:
- the lowest effective dose should be used and the daily dose should be divided into several small doses to be taken throughout the day - the use of a prolonged release formulation may be preferable to other treatment forms
- initiate specialised prenatal monitoring in order to monitor the development of the unborn, including the possible occurrence of neural tube defects and other malformations
- folate supplementation before the pregnancy may decrease the risk of neural tube defects common to all pregnancies; however the available evidence does not suggest it prevents the birth defects or malformations due to valproate exposure
Further information
The Cochrane review[footnote 10] published in November 2014 assessed 22 prospective cohort studies and 6 registry studies. The review supported findings from the European review that children exposed to valproate in utero were at an increased risk of poorer neurodevelopmental scores compared to the general study population both in infancy and when school aged.
A dose-related risk of developmental disorders was reported for valproate in 6 of the 28 studies included in the Cochrane review. However, based on the available data, it is not possible to establish a threshold dose below which no risk of developmental disorders exists.
Usage during pregnancy in the UK
Data from the Clinical Practice Research Datalink suggest that approximately 35,000 women aged 14 to 45 per year had a prescription for sodium valproate between 2010 and 2012, the majority for epilepsy. Of these, at least 375 per year had a prescription for sodium valproate while pregnant.
Future action
Pharmaceutical companies holding licences for valproate containing medicines must monitor the usage of these medicines to assess the effectiveness of these new measures on reducing the number of pregnant women taking valproate. We will continue to monitor valproate usage using the Clinical Practice Research Datalink. We will also work with stakeholders such as clinical guideline bodies to develop tools to aid decision-making for healthcare professionals and patients. We have already developed information booklets for healthcare professionals and patients (see further information below).
The product information will now be updated to reflect our current understanding of the available evidence and to make information as clear as possible.
Educational materials are available to healthcare professionals and patients in order to inform about the risks associated with valproate in female children, female adolescents, women of childbearing potential and pregnant women (see further materials below).
Call for reporting
Valproate is now a black triangle medicine and is subject to additional monitoring. Therefore please report any suspected side effects to valproate via the Yellow Card scheme www.gov.uk/yellowcard.
Further materials
Post-publication note: new communication materials have been made available to support discussion of these risks with women of childbearing potential and girls who take valproate. See the article published in February 2016 for the latest advice and materials. In January 2024, materials were updated see Drug Safety Update January 2024 for more information and the valproate guidance page for materials.
Summaries of product characteristics and patient information leaflets
Letter sent to healthcare professionals 21 Jan 2015
Information from the European Medicines Agency Nov 2014
Article citation: Drug Safety Update volume 8 issue 6 January 2015: 1
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Meador K, Reynolds MW, Crean S et al. Pregnancy outcomes in women with epilepsy: a systematic review and meta-analysis of published pregnancy registries and cohorts. Epilepsy Res. 2008;81(1):1-13. ↩
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Bromley RL, Mawer G, Clayton-Smith J, Baker GA; Liverpool and Manchester Neurodevelopment Group. Autism spectrum disorders following in utero exposure to antiepileptic drugs. Neurology. 2008;71(23):1923-4. ↩
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Thomas SV, Sukumaran S, Lukose N, George A, Sarma PS. Intellectual and language functions in children of mothers with epilepsy. Epilepsia. 2007 Dec;48(12):2234-40. ↩
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Cummings C, Stewart M, Stevenson M, Morrow J, Nelson J. Neurodevelopment of children exposed in utero to lamotrigine, sodium valproate and carbamazepine. Arch Dis Child 2011 July;96(7):643-7. ↩
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Meador KJ, Baker GA, Browning N, Cohen MJ, Bromley RL, Clayton-Smith J, Kalayjian LA, Kanner A, Liporace JD, Pennell PB, Privitera M, Loring DW; NEAD Study Group. Fetal antiepileptic drug exposure and cognitive outcomes at age 6 years (NEAD study): a prospective observational study. Lancet Neurol. 2013;12(3):244-52. ↩
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Christensen J, Grønborg TK, Sørensen MJ et al. Prenatal valproate exposure and risk of autism spectrum disorders and childhood autism. JAMA. 2013; 309(16):1696-703. ↩
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Cohen MJ, Meador KJ, Browning N, May R, Baker GA, Clayton-Smith J, Kalayjian LA, Kanner A, Liporace JD, Pennell PB, Privitera M, Loring DW; NEAD study group. Fetal antiepileptic drug exposure: Adaptive and emotional/behavioral functioning at age 6years. Epilepsy Behav. 2013;29(2):308-15. ↩
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Cohen M.J et al. Fetal Antiepileptic Drug Exposure: Motor, Adaptive and Emotional/Behavioural Functioning at age 3 years. Epilepsy Behav. 2011; 22(2):240-246 ↩
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Bromley R, Weston J, Adab N et al. Treatment for epilepsy in pregnancy: neurodevelopmental outcomes in the child. Cochrane Database Syst Rev. 2014, Issue 10 ↩