Cigarette smoking in pregnancy results in marked decrease in maternal hCG and oestradiol levels

Abstract

Summary. We have examined serum levels of oestradiol (E₂), sexhormone binding globulin (SHBG) and human chorionic gonadotrophin (hCG) during early pregnancy in relation to smoking status at the time of sampling in a series of 147 women. Smoking was associated with significantly depressed serum levels of E₂, SHBG and hCG: in smokers, E₂ levels were on average 17·6% lower (P=0·037), SHBG levels were 12·4% lower (P=0·15), and hCG levels were 21·5% lower (P=0·044). There appeared to be a steady decline in these values with increasing cigarette consumption. These lower hormone levels in smokers may explain certain adverse effects of smoking in pregnancy.