Medication Use During Pregnancy and Lactation in a Dutch Population

Medication use during pregnancy and lactation can be unavoidable, but knowledge on safety for the fetus or breastfed infant is limited among patients and healthcare providers.

This study aimed to determine (a) the prevalence of medication use in pregnant and lactating women in a tertiary academic center, (b) the types and safety of these medicines, and (c) the influence of medication use on initiation of breastfeeding.

This study used a cross-sectional survey among women ( N = 292) who underwent high-risk or low-risk deliveries. Data about their use of prescribed, over-the-counter, and homeopathic medication during pregnancy were obtained through a structured interview, followed by a questionnaire during lactation. Safety was classified according to the risk classification system from the Dutch Teratological Information Service.

Overall, 95.5% of participants used medication. One third of participants used at least one medicine with an unknown risk for the fetus. Teratogenic medication was used by 6.5% of participants, whereas 29.5% used medication with a (suspected) pharmacological effect on the fetus. Lactation was initiated by 258 (88.7%) participants, of which 84.2% used medication while breastfeeding. In 3.8% of participants, this medication was classified unsafe, but none used medication with an unknown risk. One-third of the nonlactating participants decided not to initiate breastfeeding because of medication use. In 70% of participants, this decision was appropriate.

The prevalence of overall use of medication in Dutch pregnant and lactating women admitted to a tertiary center was high. There is an urgent need for pharmacometric studies for determination of the safe use of the most frequently used medicines during pregnancy or lactation.