New study show that smoking during pregnancy have harmful changes in both maternal and fetal thyroid function ,the study made on two groups of women at different stages of pregnancy – one in the first trimester and the other in the third trimester.

Smoking

They found smoking during pregnancy make changes in the thyroid hormone levels of mothers, thyroid function during pregnancy is vital for a successful pregnancy and the decrease level of it associated with miscarriage,low birth weight,premature birth, and decrease neuropsychological Function and biological consequences of the baby

Also the study show that mother that stoped smoking in pregnancy there thyroid level were comparable to levels found in non-smokers that mean low thyroid functions