HORMONAL EVENTS IN A NEWBORB BABY GIRL

When a baby girl is born, MOM's female hormones that had been passing through the umbilical cord may continue to have an effect on the baby girl.

When the baby girl is still in the womb, early sexual differentiation depends on a hormones secreted from the Placenta (hCG). At 11-12 weeks after conception, there are brain connections in the fetus that take over and start sexual differentiation.

By the second trimester of pregnancy, the ovary starts developing follicles. This is where Estrogen comes from. Estrogen can be also made via the conversion of androgen yet this is a secondary pathway.

Peripheral blood concentrations of fetal pituitary gonadotropins (fetal-LH and fetal-FSH) peak mid-gestation and fall to minimal at birth.

A second smaller peak occurs after birth due to loss of negative feedback from maternal hormones. Therefore, the postnatal period of a baby girl has relatively high concentrations of hormones (estrogens).

In some circumstances where there is a LOT of estrogen circulating, the newborn baby girl may have effects on the neonatal breast leading to enlarged nipples and in some cases milk production. This has been commonly called “Witches’ Milk”: THIS IS PERFECTLY NORMAL. There is no need to worry and it usually normalizes by 4 weeks after birth.

Also the elevated levels of Estrogen may have an effect on the newborn baby girl's uterus (uterine lining) making it grow, and once the estrogen levels fall, one can observe a scant vaginal discharge that in some cases can be bloody. THIS IS ALSO PERFECTLY NORMAL and will normalize by the 6th week of life.

If any of these condition persists beyond the 6th week of life, then it is wise to discuss it with your doctor (pediatrician). Moms / Parents can be very alarmed by this and often reassurance is the best MEDICINE.

Knowledge is power!
Hope you find this information helpful. :)

Margarita Ochoa-Maya, MD, CDE
Womans Health, Endocrinology and Metabolism
freedomtoheal.md@gmail.com