Smoking during pregnancy and Poland sequence: results of a population-based registry and a case-control registry.

As Poland sequence (PS) could have a vascular disruptive origin, here we analyzed the possible relationship between maternal smoking during pregnancy and PS, using data from two registries with different methodologies: the Hungarian Congenital Abnormality Registry (HCAR), which is a population-based registry, and the Spanish Collaborative Study of Congenital Malformations (ECEMC), which is a hospital-based and case-control study. The results presented here in a multivariate analysis, although based on a small sample size, suggest that maternal smoking during pregnancy may increase the risk for PS by about 2-fold. This result was similar in the two studied programs with different methodologies and different uncontrolled confounding factors. However, as this is the first time that PS has been associated with maternal smoking during pregnancy, further analyses are needed to confirm our findings.