Valproate use in women aged 15-44 years: Observational study in general practice

Background Valproate is a known teratogen. In April 2018, the Medicines and Healthcare products Regulatory Agency (MHRA) restricted use in women and banned use in pregnancy, except for epilepsy with no other effective treatment. To date, there is limited information on valproate prescribing within primary care.

Aim To characterise valproate prescribing to women of childbearing age, recorded advice or general practitioner prescribed contraception and recorded pregnancies.

Design & setting A cross-sectional study of patients from all 141 general practices across three Clinical Commissioning Groups in East London.

Method Women aged 15-44 years prescribed valproate between 1/10/2017-1/1/2020 were included. Exclusion criteria were early menopause, sterilisation procedures or hysterectomy. Pseudonymised data on valproate indication, pregnancy, pre-conception and contraception advice were retrospectively extracted from general practice consultation data. Data were analysed by quarter using univariate statistics.

Results Of the total 1,042,463 registered patients, 344 women aged 15–44 years were prescribed valproate during the study period; 14 were excluded. There were 10 pregnancies during possible valproate exposure; one was terminated. During the study period, the number of women prescribed valproate significantly decreased (P=0.003). The pregnancy rate decreased from 9.9/1000 on valproate before the MHRA April 2018 warning, to an average of 2.8/1000 afterwards. Recorded pre-conception/contraception advice increased by 79%, from 24% to 43%, of women prescribed valproate.

Conclusion With continued pregnancies in women aged 15-44 years prescribed valproate, patient education and foetal outcomes remain ongoing concerns. Further improvements are needed to ensure women make informed reproductive choices and safeguard future pregnancies from valproate exposure.