What effect can a mother's hormones have on male infants during the neonatal stage?

During the neonatal stage, a mother’s hormones—particularly estrogen—can have significant effects on male infants. These hormones can lead to the development of breast tissue in male infants, a condition often referred to as gynecomastia. This is due to the transfer of maternal estrogen across the placenta during pregnancy, which can stimulate breast tissue growth during the early life of the male infant.

This phenomenon is typically temporary, as the infant’s hormonal levels normalize after birth, and most cases resolve without intervention. The presence of breast tissue in male infants is not uncommon and is a direct result of maternal hormonal influences rather than any development abnormality or disorder.

Understanding this aspect is essential, especially in the context of human hormonal interactions and their developmental impacts in neonates.