The effects of smoking during pregnancy on fetal bone metabolism

Cigarette smoking might adversely affect foetal bone metabolism. Accordingly, the purpose of our study was to analyse the influence of tobacco smoking during pregnancy on calcium-regulating hormones. Blood and saliva samples were taken from 25 smoking and 25 non-smoking healthy women at 30-32 weeks of gestation. Blood samples from the newborns were collected 24-48 hours after birth. In the smoking group, the levels of 25 (OH)-D3 were significantly lower in the newborn than in their mothers. In addition, serum PTH values were significantly lower in the newborn of smoking mothers than in those of the control group. These data suggest that passive exposure to tobacco smoke appears to affect the hormones which regulate bone metabolism in the foetus and newborn, possibly leading to a depression of the vitamin D-PTH system.