Effect of maternal active and passive smoking during pregnancy on maternal and neonatal thyroid function

The influence of maternal active and passive smoking on the maternal and neonatal thyroid function was evaluated in 45 mother-neonate pairs. The sample was divided into three groups: Active smokers [n = 16], passive smokers [n = 17] and nonsmokers as a control group [n = 12]. Sera from mothers and umbilical cord of their neonates were analyzed for nicotine metabolite, free thyroxin [free T4] and thyrotropin [TSH] using IMMIULITE immunoassay method. The study concluded that smoking during pregnancy whether active or passive may be responsible for maternal and neonatal thyroid hyperfunction. Other mechanisms than fetal thyroid hyperfunction are responsible for the retarded growth observed in these infants