[Medication use during the first trimester of pregnancy: drug safety and adoption of folic acid and ferrous sulphate].

PURPOSE: To identify the profile of use of medication during the first trimester of pregnancy with emphasis on safety assessment and on the adoption of folic acid and ferrous sulfate by pregnant women attended at a Basic Health Unit in Brazil.

METHODS

This was a cross-sectional study nested in a cohort of pregnant women. Medications were classified according to the Anatomical Therapeutic Chemical (ATC), and their safety was evaluated according to the Food and Drug Administration (FDA) and the Brazilian Health Surveillance Agency (ANVISA). The adoption of ferrous sulfate and folic acid was investigated according to the protocol set forth by the Brazilian Ministry of Health.

RESULTS

The survey included 212 pregnant women, 46.7% of whom were taking medications at the time of pregnancy diagnosis, and 97.6% used medication during the first trimester after diagnosis. The highest percentage of self-medication occurred before the beginning of prenatal care (64.9%). According to the FDA criteria, there was a high level of exposure to D and X risk drugs before the beginning of prenatal care (23.0%), which was also observed for drugs not recommended by ANVISA (36.5%). Of the surveyed sample, 32.5% did not follow the protocol of the Brazilian Ministry of Health. In all, 67.9% of pregnant women had inadequate drug exposure. There was a difference between the proportions of drugs used according to the ATC, and the main anatomical groups identified were the drugs that act on blood and blood-forming organs, and anti-infective medications for systemic use. When pregnancy was diagnosed, the use of a large number of medications that act on the genitourinary system and sex hormones (16.2%) was identified, such as oral contraceptives, a fact probably related to the percentage of unplanned pregnancies (67.0%), on the same occasion 4 pregnant women used folic acid and 3 used ferrous sulphate.

CONCLUSION

The present results show that a large number of medications are used during pregnancy. Even if there was little exposure to drugs at the time of diagnosis, there is an overuse of potentially risky medications and self-medication during the first trimester of pregnancy.