Newborns are often born or experience a variety of normal conditions after birth. These conditions include acne, yellowing of the skin known as jaundice, darker pigmentation to the skin and temporary changes in the genitals or breasts. Many of these conditions exist because of the mother's hormones passed to the fetus just before birth or to the infant during breastfeeding.
During pregnancy, hormones from the mother's bloodstream enter the fetus' body through the placenta. These hormones cause certain conditions that are apparent at birth. In addition, breastfed infants receive maternal hormones in breast milk that may also cause certain conditions that are normal and pose no risk to the baby.
This condition is caused by the normal concentration of female hormones in the mother's body during late pregnancy and hormones passed through breastfeeding.