[Self-reported adherence to prescribed medicines during pregnancy]

To assess medication adherence therapeutic during pregnancy in a sample of Brazilian women during the post-partum period.

We conducted a cross-sectional study in the obstetric unit of a university hospital, Brazil, between August and November 2010. We recruited patients aged 18 years or more, with a gestational age of more than 22 weeks whose newborns weighed more than 500 g. Patients were excluded if they used sedatives or other mind-altering drugs. Data were collected after labor using a structured questionnaire containing questions about sociodemographic characteristics, medication use, number of previous pregnancies, contraceptive methods, prenatal care, and medication adherence. Medication adherence was assessed using the four-item Morisky medication adherence scale - MMAS-4, groups were compared by the Fisher exact Test and Kruskal-Wallis Test and Χ2 de Pearson Test.

Mean age was 22.5 years (SD=6.5), and 53.8% of the pregnant women had initiated prenatal care during the first trimester of pregnancy. Of the 130 patients interviewed, 96.9% had used at least one prescribed drug during pregnancy, with an average of 2.8 drugs per patient. The major classes prescribed were antianemics (55.1%), analgesics, anti-inflammatories, and antipyretics (19.0%) and anti-infectives (7.2%). 71.6% took two to four drugs. Only 19.2% of patients were considered adherent. The variables that showed a negative influence on adherence were: higher level of education, having one's own income, earlier prenatal care and previous abortion.

Our findings indicate that, although most of the patients used prescribed drugs during pregnancy, the rate of medication adherence was low, which indicates the need for further investigation about the impact of non-adherence during pregnancy and its causes.