(101) Antibiotic Use During Pregnancy: A Swedish Drug Utilization Study from 2006 to 2019

Friday, August 26, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 432

Presenting Author(s)

Aya Nakitanda
– Karolinska Institutet, Stockholm, Stockholms l�n, Sweden

Co-Author(s)

Ingvild Odsbu
– Researcher, Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Oslo, Norway
Pär Karlsson
– Statistician, Centre for Pharmacoepidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
Laura Pazzagli
– Centre for Pharmacoepidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden

Background: Antibiotics are often prescribed during pregnancy. Evaluating the current state of antibiotic use among pregnant women is critical in informing clinical-decision making and setting research priorities.

Objectives: To describe recent trends and patterns in antibiotic use before, during and after pregnancy.

Methods: Population-based study using linked, nationwide registers. All pregnancies delivered in Sweden between 1 July 2006 and 31 December 2019 were identified from the Medical Birth Register. Data on dispensed systemic antibacterials (Anatomical Therapeutic Chemical codes J01 except J01XX05) were obtained from the Prescribed Drug Register. Prevalence of antibiotic use during pregnancy was defined as the percentage of pregnancies with at least one antibiotic prescription filled between the last menstrual period and delivery. Temporal trends in the prevalence of antibiotic use during pregnancy aggregated by calendar year, antibiotic class/substance, trimester and weeks of gestation were described.

Results: Antibiotics were dispensed in 20.7% of 1,483,889 pregnancies overall, with higher proportions among extremes of maternal age, multipleton, multiparous and caesarean section-delivered pregnancies. Phenoxymethylpenicillin (8.5%), pivmecillinam (6.4%), nitrofurantoin (4.7%), amoxicillin (1.6%) and cefadroxil (1.6%) fills were most prevalent. Tetracyclines and fluoroquinolones were dispensed to a lesser extent particularly pre-pregnancy and in the first trimester. Prevalence of use during pregnancy was highest in the second trimester (9.5%), but peaked during the first 2 weeks of puerperium. Systemic antibiotic use during pregnancy fell from 22.6% in 2006 to 18.0% in 2019. The decline was observed before, during and after pregnancy. Exceptionally, pivmecillinam use increased over the 14-year period.

Conclusions: Although antibiotic use during pregnancy in Sweden has been declining, about one in five pregnancies was exposed to systemic antibiotics.