Use of medication during pregnancy--a prospective cohort study on use and policy of prescribing.

Pregnancy is associated with special problems with respect in selection of medication and dosage, primarily due to potential teratogenic or toxic effects on the fetus by the drug itself, and secondly due to the physiologic adjustments in the mother in response to pregnancy. This prospective survey was designed to record the use of medications and the policy of prescribing during the course of pregnancy. In total, 5851 pregnant women residing in a county in southwestern Finland during the period June 15, 1987 and June 14, 1988 were studied, which is 69% of the total amount of births in the same area. Iron and vitamin supplementation was used by all the pregnant women during the third trimester, and by 35% and 88% during the first and second trimesters, respectively. Analgetics were used on an irregular basis by 12% of the pregnant women, and no correlation to the length of pregnancy could be observed. 9% of the women used medication on a regular basis for reasons such as bronchial asthma, arterial hypertension and hyperthyreosis. Some kind of a symptomatic medication was taken by 43% of the women with no correlation of the length of pregnancy, the most common symptoms needing medication being candidiasis, cough, reflux esophagitis and pregnancy-associated hyperemesis. Tocolytic agents had been given to 8% of the pregnant women. Most tocolytics were used during the end of the second trimester and beginning of the third one. It is concluded that the general use of medicines is quite reasonable in the normal pregnant population in Finland. Iron supplementation should probably be more individualized instead of regular use.