Smoking cessation: nicotine replacement therapy during pregnancy, the risk of birth defects?

The use of nicotine replacement therapy during the first twelve weeks of pregnancy appears to increase the risk of congenital malformation, suggest the results of a prospective analysis conducted from a large cohort of pregnant women and their children, published in the journal " Obstetrics & Gynecology. "

Previous data on the link between smoking and birth defects based on data collected in studies on small samples or analyzed tobacco retrospectively reported Dr. Maria Morales-Suarez-Varela, University Valencia (Spain), and the Danish and American colleagues.

A total of 76,768 women from the Danish National Birth Cohort (1997-2003) were interviewed between their 11th and 25th week of pregnancy about their smoking habits and the possible use of nicotine replacement therapy (gum, patches or inhalers) during the first twelve weeks of pregnancy. Information about the health of 20,603 children born to smoking mothers and 56,165 infants born to nonsmoking mothers were also collected including the "Hospital Medical Birth Registry", which records medical data at the time of birth or during the first year of life of the child.

The analysis of these data, children who had prenatal exposure to tobacco are not more prone to birth defects than those not exposed to maternal smoking during pregnancy, say the authors.

However, they warn, it does not necessarily reflect a lack of impact of smoking on the risk of congenital malformation, and could also result in abortion rates or greater miscarriages among smoking mothers. In addition, they point out, there is sufficient evidence to demonstrate the deleterious effects of smoking and fetotoxic to convince pregnant not to smoke during pregnancy women.

However, the results of this survey showed an increased risk of birth defects (particularly in the musculoskeletal system) for children born to mothers who did not smoke but who used nicotine replacement therapy in early pregnancy.

According to the authors, these differences could be explained by the fact that nicotine after cigarette smoke and that contained in the NRT are not absorbed through the same channels and reach peaks of different concentration.

Before these results indicating a potential risk of congenital malformations associated with the use of nicotine replacement therapy for the mother can not be regarded as final, they have yet to be confirmed by other studies, the authors warn.

In France, according to the recommendations of the consensus conference "Pregnancy and tobacco", which was held under the auspices of the National Agency for Accreditation and Evaluation in Health (Anaes, whose functions are now the High Health Authority or HAS), "first-line psychological and / or behavior may be offered to help the smoker to remove barriers to smoking cessation and pregnant women to choose the appropriate means to achieve this approach ".

However, say French experts, "in case of failure or lack of motivation for one psychological and behavioral approach, a nicotine replacement therapy (NRT) may be offered [...] at any time to support a smoking pregnant woman. "