A leading neuroscientist has claimed that smoking and drug use during pregnancy could raise the chance of having a baby who would turn out to be gay.

According to Britain’s Sunday Times, Dr Dick Swabb, professor of neurobiology at Amsterdam University, said that the brain development during pregnancy and early childhood is directly linked to the kind of people we become in adulthood.

Dr Swabb’s new book, ‘We Are Our Brains,’ has cited multiple academic studies showing how a pregnant mother’s lifestyle can possibly affect her child, News.com.au reported.

One of the studies compared women whose moms were given synthetic oestrogen while they were pregnant between 1939 and 1960 in order to cut the miscarriage risk.

Dr Swabb said that pre-birth exposure to both nicotine and amphetamines boosts the chance of lesbian daughters.

He said that pregnant women suffering from stress are likelier to have homosexual kids of both genders as their raised level of the stress hormone cortisol affects the production of foetal sex hormones.