Smoking while pregnant has been shown to cause delayed growth, low birth weight, and premature delivery, but now an Amsterdam University professor is claiming that smoking and undergoing stress during pregnancy for a developing fetus can in fact impact the child’s sexual orientation, reports The Sunday Times of London.
According to neuroscientist Dr. Dick Swaab, pre-birth exposure to nicotine can increase the chances of girls becoming lesbian or bisexual and drinking or drug taking can lower a child’s IQ. The researcher also surmised that a boy with several older brothers has a higher chance of being gay possibly because the development of the mother’s immune system to have stronger responses to male hormones with each son born.
Not only does nicotine play a part in sexual orientation but so does stress. Dr. Swaab contends, “Pregnant women suffering from stress are also more likely to have homosexual children of both genders because their raised level of the stress hormone cortisol affects the production of fetal sex hormones,” he added.
Dr. Swaab says that the fetal brain begins to form at about the two-week mark, so any toxin that is introduced could have an effect on the unborn child.
The ingestion of synthetic hormones while pregnant can also play a role in determining sexual orientation as well, as evidenced with a group of studies done on women between 1939 and 1960 to reduce their miscarriage risk. The women who ingested the synthetic estrogen had a greater chance of bisexuality and lesbianism in their daughters.
Swaab concludes that even though lifestyle factors play a major role in fetal brain formation, genetics still holds the most weight.