Postdoc University Hospital Basel (Hospital Pharmacy) Basel, Switzerland
Background: The use of prescribed drugs during pregnancy in Switzerland is not known.
Objectives: To evaluate the utilization of prescribed drugs during pregnancy in outpatient care in Switzerland.
Methods: We conducted a retrospective descriptive study using anonymized healthcare claims data of one of the biggest health insurance companies in Switzerland, the insurance group Helsana (2015-2021). We established a cohort of pregnancies by identifying deliveries and estimating the date of the last menstrual period. We quantified the utilization of drugs (≥1 and ≥5 filled distinct drug prescriptions) during pregnancy overall, by trimester (T), and by age category. We also quantified the prevalence of exposure to the most frequently filled drug prescriptions during pregnancy and by trimester. Results were weighted based on the demographic distribution of the Helsana population relative to the Swiss population.
Results: We identified a weighted pregnancy population of 502’100 pregnancies with a median maternal age at delivery of 32 years (IQR=28-35). During pregnancy, 87.7% of women filled ≥1 drug prescription (97.8% when including vitamins, minerals, iron preparations, iodide, and vaccinations) with the highest percentage in T3 (67.2% vs. 59.5% in T1/T2) and among women < 26 years of age (90.6% vs. 87.3% in 26-35, 87.5% in ≥35). Overall, 30% of pregnant women filled ≥5 distinct drug prescriptions during pregnancy. Among the top 5 most frequently filled drug prescriptions during pregnancy were paracetamol (also called acetaminophen, 8.3%), progesterone (5.0%, limited to T1), metoclopramide (4.1%), dequalinium chloride (vaginal application, 3.8%) and levothyroxine (3.4%). Paracetamol was the most frequently filled drug prescription in T2 (9.9%) and T3 (7.0%), but not in T1 (rank 3: 8.2%, rank 1: progesterone with 10.9%). In T1, progesterone was followed by antiemetic drugs with 9.9%, of which 8.6% was metoclopramide (ondansetron: 1.3%). In T2, paracetamol was followed by dequalinium chloride (vaginal application, 4.1%), levothyroxine (4.0%), and amoxicillin with clavulanic acid (2.8%). In T3, anti-D immunoglobulins (3.7%) and drugs for the treatment of gastroesophageal reflux (proton pump inhibitors: 7.0%, mineral antacids: 3.6%, ranitidine: 1.5%) represented, next to paracetamol, the top 3 most frequently filled drug prescriptions.
Conclusions: The most frequently used drugs during pregnancy in Switzerland are safe. The frequent use of drugs during pregnancy underlines the importance of evidence on the benefit-risk profile of individual drugs used during pregnancy.
