Evaluation of the impact of maternal smoking on ultrasound and endocrinological markers of first trimester placentation

ObjectivesTo study the effect of maternal smoking on 2D ultrasound measurements and maternal serum (MS) levels of endocrinologic markers of placentation.Study designProspective population-based cohort study of 32 smokers and 96 non-smoking controls with a normal pregnancy outcome.Main outcome measuresPlacental thickness and 2D-volume and MS levels of pregnancy-associated plasma protein A (PAPP-A) and free-beta human chorionic gonadotrophin (fβhCG) at 11-13+ 6 weeks of gestation and mid-trimester MS α-fetoprotein (AFP), unconjugated estriol (uE3) and inhibin A levels.ResultsThe MS levels of fβhCG and PAPP-A were significantly (P < 0.01 and P < 0.001, respectively) lower in the serum and the level of inhibin A significantly (P < 0.001) higher in the smokers than in controls. There was no significant difference for the MSAFP, MSuE3 placental thickness, basal plate surface and volume between the groups.ConclusionThe placental morphological alterations secondary to maternal smoking are mainly at the level of the villous trophoblast and are not associated with changes in the placental size or utero-placental interface during the first trimester of pregnancy.