[A risk analysis of congenital defects due to drug intake during pregnancy. Spanish Collaborative Study of Congenital Malformations].

BACKGROUND: Illicit drug abuse is a major area of interest, for clinicians, as well as for public health and social authorities. But one of the major concerns is the illicit drug abuse during the periconceptional period and throughout pregnancy, because of its potential effect on the embryo and fetus. In this study we analyze the possible risk of illicit drug abuse during pregnancy for different selected congenital defects.

MATERIALS AND METHODS: We analyzed the annual evolution of the proportion of mothers who are addicted to illicit drugs, as well as some of their characteristics. We also performed a case-control study using different models of multiple logistic regression analyses, controlling possible confounding factors.

RESULTS: We observed that the proportion of mothers who are addicted to illicit drugs shows an increasing liner trend over time. On the other hand, these mothers are younger that those who are not consumers of illicit drugs, and have an overall risk for congenital defects of 1.84 (p = 0.007). We also studied the different selected types of congenital defects, controlling the potential effect of the following variables: maternal age, maternal cultural level, maternal alcohol, maternal smoking, and vitamins/minerals during pregnancy. In these analyses we obtained statistically significant increased risks for: neural tube defects, choanal atresia, esophageal atresia, gastroschisis, anal atresia, and postaxial polydactyly.

CONCLUSIONS: The women who are addicted to illicit drugs during pregnancy, have an increased risk for infants with several congenital defects. The way to prevent these effects should be based on a good information about this aspect to the general population, as well as on a careful medical control of the nutrition of these mothers and their health and social conditions during gestation, and the treatment of their addiction before and during pregnancy.