What is happening

The NHS puts all of it in one place on its newborn page, and the explanation is the same for every part: "Quite often, a newborn's breasts are a little swollen and ooze some milk, whether they are a boy or a girl. Your newborn's genitals may appear swollen initially but will look normal within a few weeks. Baby girls also sometimes bleed a bit or have a white, cloudy discharge from the vagina. All this is caused by hormones passing from you to your baby before birth. Do not be concerned."

Your oestrogen crosses the placenta during pregnancy. At birth that supply stops abruptly, and the newborn's body responds to the withdrawal in the same way an adult body would — briefly, and then it settles. Clinicians sometimes call this mini-puberty. It affects babies of both sexes.

Swollen breasts, in boys and girls

The AAP describes it in its account of how newborns look: "In the first few weeks following birth, babies can be affected by their mother's hormones they were exposed to during pregnancy. As a result, babies' breasts may be enlarged temporarily, and they might even secrete a few drops of milk. This is normal. It may occur in boys and girls, and normally lasts less than a week, although it can last longer."

The instruction that matters is the next sentence: "It is best not to press or squeeze a baby's breasts, since this won't reduce swelling and could cause irritation." Squeezing does not empty anything and risks introducing infection into breast tissue that is already swollen. Leave it entirely alone.

The AAP gives less than a week as typical, with a longer tail in some babies. The NHS's framing for the genital swelling — normal within a few weeks — is the outer end of the range.

Discharge and bleeding in a baby girl

The AAP calls it by name: "In infant girls, there could be a discharge from the vagina, often white mucus and sometimes containing a little blood. Although disconcerting to some new parents, this so-called pseudomenses is harmless."

The HSE says the same thing in nappy terms: "If you have a girl, you may see a white discharge on her nappy for a few days after birth. There may also be a little blood. This is caused by hormones that have crossed the placenta to your baby. But these will soon disappear from her system. It's nothing to worry about."

The AAP's guidance on newborn nappies adds a timing rule that is genuinely useful, because it tells you when this stops being the explanation: newborn girls may have a small spot of blood in the nappy, usually in the first week after birth. "After that time, however, the presence of actual blood in the urine or a bloody spot on the diaper is never normal, and your pediatrician should be notified."

So: first week, hormonal, expected. Later than that, get it looked at.

The pink stain that is not blood

One more thing turns up in the same nappies and is often mistaken for bleeding. The AAP: in the first week after birth you may see a pink or brick-red stain on the nappy, "often mistaken for blood. In fact, this stain is usually a sign of highly concentrated urine, which has a pinkish color." These are urate crystals. The AAP's threshold: "As long as the baby is wetting at least four diapers a day, there probably is no cause for concern. If the pinkish staining persists, consult your pediatrician." In practice, concentrated urine in the first days often means feeding is still getting established, which is worth mentioning to your midwife.

Swollen genitals in a baby boy

The same hormones swell a newborn boy's scrotum, and the AAP notes that newborn genitals "can be reddish and seem large for bodies so small". Some boys also have a hydrocele, a build-up of fluid in a sac inside the scrotum, which the AAP says shrinks gradually without treatment over several months as the fluid is reabsorbed.

The AAP gives one clear exception: "If the scrotum swells suddenly or gets larger when he cries, notify your pediatrician; this could be a sign of an inguinal hernia, which requires treatment." Sudden swelling, swelling that comes and goes with crying, or a firm painful lump in the groin should be looked at the same day.

What actually helps

Nothing to the breasts. No squeezing, no massage, no warm compresses, no products.
Wipe front to back when cleaning a baby girl, and clean gently with water and cotton wool rather than trying to clean inside the labia. The discharge is meant to be there.
Do not try to clean it away. The white material is a normal secretion, not dirt.
Change nappies often and give some nappy-off time, which is the standard advice for keeping the area healthy.
Note what you see and when. Dates matter more than descriptions here, because the timing is what separates hormonal from not.

The check that covers this

The NHS's newborn physical examination, offered within the first 72 hours, includes the genitals. NICE's postnatal care guideline NG194 specifies that the examination checks "genitalia and anus: completeness and patency and undescended testes in boys". It is repeated at six to eight weeks. If anything about this area is worrying you, those appointments exist precisely for it — but you do not have to wait for one.

When to call

Speak to your midwife, health visitor, public health nurse or GP if:

Blood appears in a baby girl's nappy after the first week of life.
A breast is red, hot, hard, or your baby cries when it is touched — that suggests infection rather than swelling.
Swelling is on one side only, or is getting bigger rather than smaller.
Breast swelling or discharge is still there well beyond the first few weeks.
A baby boy's scrotum swells suddenly, or enlarges when he cries.
There is a foul-smelling or green discharge, or the skin is broken and weeping.

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand) if your baby: has a temperature of 38C (100.4F) or above or below 36C (96.8F); looks pale, ashen, mottled or blue; is unresponsive or unrousable; has a weak, abnormally high-pitched or continuous cry; is grunting or breathing over 60 breaths a minute; has a bulging fontanelle, neck stiffness or a seizure; or has a rash that does not fade under a pressed glass. Those are NICE's NG194 red flags for serious illness in young babies. A fever in a baby under three months is an emergency in its own right, whatever else is going on.

What to let go of

None of this is a sign of early puberty, a hormone problem, or anything you did or ate. It is withdrawal from a hormone supply that ended at birth, it affects babies of both sexes, and it goes without treatment. The only active instruction any source gives is the AAP's: do not squeeze.

Newborn Swollen Breasts and Discharge