Maternal characteristics associated with pregnancy exposure to FDA category C, D, and X drugs in a Canadian population.

PURPOSE: To estimate the frequency of exposure to prescription Food and Drug Administration (FDA) category C, D, and X drugs in pregnant women, and to analyze the maternal characteristics associated with such an exposure.

METHODS: A 50% random sample of women who gave a birth in Saskatchewan between January 1, 1997 and December 31, 2000 was chosen for the study. The rate of exposure to FDA category C, D, or X drugs recorded in the pharmacist database was estimated. Associations of exposure to FDA category C, D, and X drugs with maternal characteristics were evaluated using multiple logistical regression, with adjusted odds ratios (ORs) and its 95% confidence intervals (CIs) as the association measures.

RESULTS: A total of 18 575 women were included in this study. Among them, 3604 (19.4%) had exposure to one or more FDA category C, D, and X drugs during pregnancy. Category C drugs were the most frequently used drugs (15.8%), followed by D drugs (5.2%), and X drugs (3.9%). Women with chronic health conditions had fourfold at increased risk of exposure than women without. Regardless of health status, women who were <20 years of age, who had a parity > or =3, and who were on social assistance plan were at increased risk of pregnancy exposure to these drugs.

CONCLUSIONS: About 19.4% pregnant women are exposed to FDA C, D or X drugs during pregnancy. Women with chronic diseases, younger age, increased parity, and under social assistance are at increased risk of exposure to FDA C, D, or X drugs.