Annie was a beautiful newborn female, the product of a term vaginal delivery. She went home with mom on the second day of life. Two days later she came in for routine weight check and evaluation for jaundice. Mom’s breast milk had come in and she was feeding nicely.
A concern of the new parents was the fact that baby Annie had swollen and firm breasts. I explained to them that this was completely normal. It was the result of high levels of progesterone and estrogen she had been exposed to while in the uterus. These hormones were from mom and crossed the placenta during pregnancy. Annie’s breasts were responding to the high hormonal levels in a normal manner. This can be seen in both male and female newborns and will last for a matter of weeks. The rest of her exam was normal and I would re-check her in a week.
Two days later Annie’s name was on the schedule for a sick call. This time the complaint was vaginal bleeding. Her parents seemed worried, explaining that the night before, during a diaper change, they noticed vaginal bleeding. It was a small amount. They didn’t want to panic or overreact, but in the morning they were shocked to see quite a bit of blood and mucus. That prompted the visit to the office. I re-examined Annie. She had a perfectly normal exam including the vaginal area. I told them that vaginal bleeding was a common and normal finding in newborns. Again it was related to maternal hormones they are exposed to during the pregnancy. These hormones will actually cause maturation of the lining of the fetal uterus. When the baby is born the levels of maternal hormones are abruptly stopped. This causes the lining of the uterus to “slough” essentially like a normal period. One study looked at 350 normal term newborn females. They found that most had some degree of vaginal bleeding. However, it was only grossly obvious in around 3.3%. The peak age was five days and it lasted only a few days. They were quite relieved and said that they would see me in six days for her follow-up visit.
Well, we didn’t quite make it to the follow-up visit, as Annie was back two days later. This time BOTH sets of grandparents accompanied Annie and her parents to the office. The chief complaint was milk production from her breasts. One of Annie’s grandmothers said, “I’ve got eight grandchildren and I raised four children of my own. You can’t tell me that this is normal. This poor little baby is lactating!”
Sure enough, Annie did have milk production. As I looked at the parents, dad asked in a knowing voice, “Hormones?….” I then explained to them that this, too, was hormonally driven and was very normal. During pregnancy, the fetus is exposed to high levels of maternal hormones which cause the breast enlargement that we talked about. After birth, high levels of Prolactin and Growth Hormone are passed to the baby through the breast milk. There is also a brief surge in pituitary hormone and thyroid hormone released by the baby which can stimulate milk production. This phenomenon is common and occurs in up to 5% of all TERM newborns, both male and female. It is not common in premature infants.
In the old literature, it was referred to as “witches’ milk”. It was thought to be stolen from sleeping babies by witches to feed those close to them. I assured them that Annie was a perfectly healthy newborn female and that all of this was not uncommon and would pass.
I think that Annie’s grandmother was still a bit skeptical as she muttered, “Well, I never…Witches’ milk and mini-periods! I just don’t know!” More importantly, Annie’s parents were relieved and comfortable with all that we talked about. As they were leaving, dad looked at me and sighed, “Maybe next time we’ll have a boy!”