Hormones in the womb could have an effect on later sexual behavior
If women also take the hormone progesterone during pregnancy, this could affect their child's sexual orientation in the long term. This is the result of a US study that was recently published in the archives of Sexual Behavior. According to this, men and women of mothers treated with progesterone were comparatively more likely to not feel heterosexual. Instead, they often defined themselves as bisexual or homosexual.
Progesterone controls the natural cycle
The sex hormone progesterone (also called "luteal hormone") is naturally produced both in the body of women and (to a lesser extent) by men. Among other things, it regulates the cycle in women and prepares the uterus for implantation of a fertilized egg. During pregnancy, it takes on a protective function by ensuring that the uterine muscles are relaxed and that premature labor does not occur. For this reason it is often used to avoid complications such as miscarriages and premature births.
A team of scientists led by June Reinisch from the Kinsey Institute in Bloomington has now discovered in a small study that the addition of additional progesterone during pregnancy could potentially have a long-term effect on the unborn baby. Because the progesterone can possibly have an impact on later sexual orientation.
Researchers examine data from 34 subjects
The researchers came to this assumption after evaluating the data from 17 female and 17 male subjects whose mothers had taken a progesterone preparation (lutocycline) during pregnancy to prevent miscarriage. The 34 participants came from a Danish cohort study from the 1980s and were all born between 1959 and 1961 in Copenhagen University Hospital (Denmark).
The men and women were compared to a carefully selected control group who had no prenatal contact with lutocycline or other hormone medication, but otherwise agreed with the study participants based on 14 relevant physical, medical and socio-economic factors. At the age of 20, the subjects of both groups were asked about their sexual orientation, self-identification and their own sexual history.
One in five describes themselves as non-heterosexual
The comparison of both groups showed that the men and women whose mothers had taken the additional hormone during pregnancy described themselves significantly less often than heterosexual, the researchers write in their report. One in five from this group therefore defined themselves as bisexual or homosexual. Compared to the control group, it was also more likely that the test subjects had already had sexual experiences with the same gender and had already been drawn to their own or both genders.
"We found that progesterone exposure was associated with increased non-heterosexual self-identification, attraction to the same or two genders, and same-sex sexual behavior," the researchers report.
The role of the hormone needs further research
"The results underline the likelihood that prenatal exposure to progesterone can have long-term consequences for human sexual behavior," the researchers conclude. Further studies with children of progesterone-treated mothers would now have to follow to find out more about the role of this hormone in human behavioral development, the scientists continued. (No)