Medication adherence among pregnant women with hypothyroidism—missed opportunities to improve reproductive health? A cross-sectional, web-based study

• This is the first study on adherence to hypothyroidism treatment in pregnancy.
• Adherence in pregnancy is comparatively high but there is room for improvement.
• Pregnant women might benefit from proper risk communication and information framing.

ObjectiveTo evaluate patterns of and factors associated with a lack of pharmacotherapy as well as low adherence to treatment of hypothyroidism in pregnancy.MethodsThis multinational, cross-sectional, internet-based study recruited pregnant woman in 18 countries. Data about women’s socio-demographic and medical characteristics, medication adherence (8-item Morisky Medication Adherence Scale), beliefs about medication (Beliefs about Medicine Questionnaire), and personality traits (Big Five Personality Trait questionnaire) were collected via an online questionnaire.Results229 of 5095 women had hypothyroidism during pregnancy; of these, 93% reported hypothyroidism pharmacotherapy. Adherence was low among 17% (95% CI: 12.5–22.5%) of medicated women, whilst it was moderate and high among 44% and 39%, respectively. Not using folic acid and not living in a stable relationship were associated with an increased likelihood for untreated hypothyroidism. Younger maternal age and not using folic acid in pregnancy were factors significantly associated with low adherence. Conscientiousness and the perception that the benefit of pharmacotherapy outweighed the risks were associated with higher levels of adherence.ConclusionThere is room for improvement of adherence to hypothyroidism treatment in pregnancy.Practice implicationsCounselling of women with hypothyroidism in pregnancy should include a proper risk communication and information framing, to ameliorate maternal and foetal health.