Background: There are few studies on the subject of drug use during pregnancy over the last decades. The aim of this study was to examine the self-reported prevalence of drug use among pregnant women in Oslo, which type of drugs are most frequently used and to describe changes in drug intake during the first 17-18 gestational weeks.
Material and method: 1749 pregnant women, 86 % of the invited and 92 % of those who accepted the invitation, answered a self-completion questionnaire at the antenatal visit at Ullevål University Hospital. They were asked to name which drugs, if any, they had used against pregnancy related symptoms and also other drugs used during the last six months prior to pregnancy, during gestational weeks 0-6, 7-12 and after week 13, to specify the name of the drugs used, and to report the number of days of consumption.
Results: At least one episode of drug use was reported by 47% of the sample during all four time intervals combined. Those reporting drug use, reported in average 1,4 preparations per woman. During pregnancy 43 % had used drugs. Most frequently used drug groups were analgesics (93 % was paracetamol), systemic antibiotics, antihistamines and asthma/allergy-medication. As a whole these four groups constituted 83 % of drugs consumed. During pregnancy, consumption was reported by an increasing proportion of women. During weeks 7-12 of pregnancy, most women reported intake of drugs in these four groups. There is a significant correlation between use of analgesics in weeks 0-6 and both weeks 7-12 and after week 13 (McNemars test p<0,001).
Interpretation: The drug use increases after pregnancy recognition. Still the overall use of drugs must be considered low, as only half of the women report any use during the first 17-18 weeks of pregnancy. Of those using analgesics in early pregnancy, many continue to use analgesics also later in pregnancy.