0692 Medication Use and Restless Legs Syndrome in Pregnancy Among Nulliparous Women

Introduction Several antiemetics and antidepressants have been associated with the exacerbation of restless legs syndrome (RLS) in non-pregnant adults. Whether this relationship exists among pregnant individuals is uncertain. We investigated whether taking potentially RLS-exacerbating medications during pregnancy is associated with a higher likelihood of RLS symptoms. Methods In this prospective study conducted at 8 U.S. sites, structured questions were utilized to capture all medications taken in early (during pregnancy until study visit 1 (6-13 weeks)) and mid-pregnancy (between study visits 2 (16-21 weeks) and 3 (22-29 weeks)). The use (yes/no) of five categories of potentially RLS-exacerbating medications was determined: first-generation antihistamines, serotonergic antidepressants, dopamine antagonists, tricyclic antidepressants, and mirtazapine. Primary outcome variables were the presence of RLS symptoms at study visits 1 and 3, determined by a questionnaire based on International RLS Study Group diagnostic criteria. Poisson regression with robust standard errors estimated the relative risk of RLS symptoms by medication use. Multivariable models included a priori covariates of age, race and ethnicity (as socially constructed variables), and recent tobacco use. Results Of 8,057 participants (age 27.2±5.4 years) who completed both medication-use and RLS questionnaires at least once, 12% and 8.7% took potentially RLS-exacerbating medications in early and mid-pregnancy, respectively. The most frequent medications were first-generation antihistamines (early: 6.6%, mid: 5.3%) and serotonergic antidepressants (early: 4.6%, mid: 3.1%), followed by dopamine antagonists (early: 1.7%, mid: 0.9%). Few participants (≤0.2%) used tricyclic antidepressants or mirtazapine. The prevalence of RLS symptoms was 18% in early pregnancy and 31% in mid-pregnancy. After multivariable adjustment, first-generation antihistamine use was associated with a higher prevalence of RLS symptoms in early (adjusted relative risk [aRR], 1.29; 95% confidence interval [CI], 1.08-1.54; p=0.005) and mid-pregnancy (aRR, 1.17; CI, 1.01-1.36; p=0.042). Similarly, serotonergic antidepressant use was associated with a higher prevalence of RLS symptoms in early (aRR, 1.83; CI, 1.55-2.17; p< 0.001) and mid-pregnancy (aRR, 1.25; CI, 1.05-1.50; p=0.013). No association was found between dopamine antagonists, tricyclic antidepressants, or mirtazapine and RLS symptoms. Conclusion There was a higher prevalence of RLS symptoms in people taking first-generation antihistamines or serotonergic antidepressants during pregnancy. Support (if any) R01HL105549, U10HL119991, U10HL119989, U10HL120034, U10HL119990, U10HL120006, U10HL119992, U10HL120019, U10HL119993, U10HL120018