What Causes Breast Buds in Babies?

Medically Reviewed on 5/12/2022

How do a pregnant woman's hormones affect her unborn child?

Breast buds in babies
Breast buds are always normal in newborns.

The environment provided to the baby while in the womb is crucial. It determines the growth and development of the baby in utero, as well as after the baby is born. What the mother consumes (including the medications) can affect the baby. Thus, the mother must eat right and avoid exposure to harmful substances including smoking and alcohol during pregnancy. Even stress and anxiety can affect the growing baby. For example, maternal stress can cause excessive secretion of certain hormones, especially steroid hormones, which can have a long-term effect on the baby’s health. Hormones are chemical messengers through which the activity of various cells and tissues is regulated. The baby also communicates its nutritional needs to the mother through hormones. Though many substances, including hormones, have a temporary effect on the baby, some chemicals may have a lasting effect on the baby’s growth and development.

What are breast buds? What causes breast buds in babies?

When inside the womb, babies are exposed to various substances, including the hormones from the mother’s blood. One such hormone is estrogen. Its levels increase during pregnancy, causing breast enlargement in the pregnant woman. The estrogen in the mother’s blood can reach the baby through the placenta, causing the development of breast buds. Breast buds are small disc-shaped lumps felt under the nipple and areola (a small circular dark area surrounding the nipple).

What signs and symptoms may accompany breast buds in babies?

There may also be some clear or milky discharge from the breast buds. This is also called the witch's milk. The discharge generally goes away within 2 weeks of birth.

When do breast buds in babies go away?

After the baby is born, the blood levels of estrogen (from the mother) fall, which gradually causes the breast buds to go away. Generally, breast buds go away by the time the baby is 1 week to 6 months of age. In some babies, however, the breast buds may last longer.

When to call the doctor with your concerns about your baby's breast buds

Do not massage or squeeze the baby’s breasts because it can cause skin irritation or infection. Contact the doctor under the following circumstances:

  • The baby develops a fever.
  • There is redness or the presence of red streaks on the breasts.
  • The breast swelling lasts longer than 6 months.
  • There is bloody or foul-smelling discharge from the nipples.
  • The baby is lethargic.
  • The baby doesn't take proper feeds.
  • The milk discharge lasts over 2 months in the baby.
  • The breast buds last beyond 6 months of age.

How else can estrogen exposure in utero affect a newborn?

Estrogen may also cause certain temporary changes in a newborn girl’s vagina. These include the following:

  • Physiologic leukorrhea: It refers to the discharge of white fluid from the newborn baby’s vagina.
  • Puffy labia: The labia are the fleshy tissue folds surrounding the vagina. They may become puffy because of estrogen exposure.
  • Bleeding through the vagina: Some newborn girls may have a small amount of bleeding through the vagina.

These changes are temporary and generally, go away by the time the baby is 2 months of age.


Newborn babies don't sleep very much. See Answer
Medically Reviewed on 5/12/2022
Grewal, H. "What Are Neonatal Breast Disorders and How Are They Treated?" Medscape. May 3, 2021. <https://www.medscape.com/answers/935410-121003/what-are-neonatal-breast-disorders-and-how-are-they-treated>.

Seattle Children's Hospital. "Breast Symptoms-Child." May 30, 2021. <https://www.seattlechildrens.org/conditions/a-z/breast-symptoms-child/>.