Daphne Garrido
Preprint 3 · September 2026 - Preprint on Zenodo
Prenatal Endocrine Organization and Gender Development.pdf
Long before a child can describe a gender identity, an extraordinary biological process has already unfolded.
Hormones circulate. Receptors detect them. Enzymes transform them. The placenta modifies the fetal environment. Different tissues become sensitive at different times.
Together, these processes help organize sexual development throughout the body.
That makes developmental endocrinology an obvious place to investigate gender.
If sex steroids help differentiate bodies, could variation in those same signals influence later gender identity?
Human biology offers several remarkable natural experiments capable of probing that question.
Their answer is neither hormonal irrelevance nor hormonal destiny.
A hormone matters only when a biological system can respond to it.
Two developing fetuses could have similar circulating androgen concentrations while experiencing very different effective androgen signaling because their receptors function differently.
Local metabolism matters too.
Enzymes can transform steroids into more or less active forms. Placental biology influences fetal exposure. Different tissues may respond differently to the same signal.
Timing matters as well.