One of the earliest studies of the impact of biological factors on sexual orientation found that if the mother experienced severe stress during the second trimester

the chance of a female child developing a same-sex sexual orientation is significantly higher.

the chance of a male child developing a heterosexual orientation is significantly higher.

the chance of either a male or female child developing a same-sex sexual orientation is significantly lower.a

the chance of a male child developing a same-sex sexual orientation is significantly higher.