Enduring prenatal androgen effects on the female brain

Area of Science:

• Neuroscience
• Endocrinology
• Human Anatomy

Background:

• Structural brain sex differences emerge early in development.
• Prenatal androgens are hypothesized contributors to these differences, but evidence is inconclusive.
• Congenital adrenal hyperplasia (CAH) offers a model to study androgen effects due to altered prenatal androgen levels in females.

Purpose of the Study:

• To investigate the impact of prenatal androgen exposure on human brain anatomy.
• To assess if elevated prenatal androgens in females with CAH lead to more male-typical brain structures.
• To examine brain anatomy in males with CAH compared to controls.

Main Methods:

• Utilized the largest sample of individuals with CAH to date, pair-matched with controls.
• Quantified anatomical sex differences using T1-weighted brain imaging.
• Employed a relevance-vector machine to generate a probabilistic brain sex index.

Main Results:

• Females with CAH displayed significantly more male-typical brain characteristics compared to female controls.
• No significant differences in brain anatomy were found between males with CAH and male controls.
• The findings indicate a shift towards male-typical brain anatomy in females exposed to high prenatal androgens.

Conclusions:

• Prenatal androgen exposure has formative effects on human brain anatomy.
• These effects persist into adulthood, influencing brain structure.
• The study supports the role of prenatal androgens in shaping sex differences in the brain.