4 Unexpected Causes Of Swollen Breasts In Newborns

✔ Research-backed

MomJunction believes in providing reliable, research-backed information to you. As per our strong editorial policy requirements, we base our health articles on references (citations) taken from authority sites, international journals, and research studies. However, if you find any incongruencies, feel free to write to us.

Swollen breasts in newborns is a common finding often noticed by parents or caregivers within a few days after birth. Slight swelling in the breast area is not a cause for concern, and this is due to the effects of increased levels of estrogeniA sex hormone that helps develop female sexual characteristics and manages their reproductive health. hormones in pregnancy for maternal breast enlargement (1)

Usually, this swelling disappears after two weeks of life when the hormones disappear in the baby’s body (2). Read on to know more about swollen breasts in newborns.

In This Article

Hormonal Changes In Babies

Swollen breasts are a common concern for parents of newborns, but it’s normally nothing serious (2).

  • The swollen breasts can, at times, produce a milk-like liquid. Do not be alarmed as galactorrhea in babies can be normal. Also, do not squeeze the nipples to try and get the milk out. If you just leave it alone, it will resolve on its own (3).
  • This swollen breast happens because the mother’s hormones are passed to the newborn baby before delivery.
  • Swollen breasts appear within a few days after the delivery and will disappear within a few weeks but can take up to a few months to completely go away.

protip_icon Quick fact
The usual diameter of the breast budiA small, disc-shaped lump under the nipple and areola, known to be caused by maternal estrogen. in the first few weeks of life measures one to two centimeters (1).

Causes Of Swollen Breasts In Newborns

Many parents may get tensed by seeing the swollen breasts in infants, but once the cause for these swollen breasts is known, you will feel relaxed (4) (5).

  1. Typically in a pregnant woman, there are many changes happening physically and mentally as well. You can notice changes in the breast during your entire pregnancy.

    You may notice changes in your breasts during pregnancy

    Image: Shutterstock

  1. In the final days of your pregnancy, you can see such changes a lot; this is due to your body preparing itself for breastfeeding your baby.
  1. These hormonal changes are passed to the infant also and the same effect is seen in them where their prolactin levels change due to the changing maternal estrogen levels.
  1. When a baby is in the mother’s womb, he or she absorbs many hormones from the mother’s blood. But after the baby is born, this regular supply of chemicals is cut off. Due to this, certain hormonal changes happen in the babies, which are generally temporary in nature.
protip_icon Did you know?
The milk secreted from the enlarged breasts of an infant is also known as Witch’s milk and it resembles maternal milk in terms of IgAiThe antibody found in the mucus membranes of the respiratory and digestive systems, and breast milk, tears, and saliva. , IgGiThe most common antibody found in blood and other body fluids, which helps fight viral and bacterial infections. , lactoferriniA iron-binding protein found in colostrum and breastmilk that helps develop immunity. , lysozymeiAn enzyme found in breastmilk, saliva, tears, and mucus that has antimicrobial properties. and lactalbuminiA protein found in whey that regulates lactose synthesis and plays an essential role in milk production. content (1).

Tips For Concerned Parents

It can be worrying for the parents to see these changes in their newborn baby’s body. Always check with your doctor if you are unsure. Here are some general do’s and don’ts to follow at home.

  • Some parents try to pinch the swollen area too much and see if that will help in reducing the swollen breast, but that will cause irritation to the newborn babies (6). Avoid doing this.
  • Since this is not a serious problem, give it some time to shrink naturally. This will disappear around the 5th week of the baby’s birth.
  • Do not massage or touch the swollen area too many times. All you should do is just wash them cleanly during the bath. Too much massage or pinching the swollen area can cause infection.

    Gently clean the swollen breasts in your newborn

    Image: Shutterstock

When You Should Consult A Doctor

As discussed earlier, swollen breasts in newborn are not worrisome since they will shrink naturally in a few weeks. However, you should consult a doctor in the following cases:

  • If the swollen breast appears red
  • If your baby has a high fever along with a swollen breast
  • If the swelling is increasing everyday
Consult a pediatrician if your baby has fever along with swollen breasts

Image: Shutterstock

As parents, it is normal to worry about anything that seems unusual for your infant. Swollen breasts in newborns are usually caused due to the effect of the high estrogen environment while inside the womb or during birth. It subsides within a few weeks of life and is not a cause of concern. However, avoid pinching or massaging the area even if there is whitish liquid discharge, and clean them during bath. Also, if the swelling increases or is accompanied by redness or fever, or a purulent discharge seek a suggestion from a pediatrician as it might indicate infantile mastitis (7).

Frequently Asked Questions

1. How long do breast buds last in newborns?

Babies (boys and girls) frequently have breast buds that increase during the first six to 18 months of life but typically regress by age two (8).

2. Is it normal for a baby boy to have a lump in his breast?

Yes. It’s normal for baby boys and girls to develop swollen breasts for lumps, which may go away by the second week of life as the hormones leave the newborn’s body (2).

3. How do I know if my baby girl has breast buds?

During infancy, any small, disc-shaped lump under the areola could be a breast bud. Mostly, a breast bud can be felt under the nipple and areola in babies (6).

Infographic: Things To Remember About Swollen Breasts In Newborn

Swollen breasts in newborns, or neonatal breast engorgement, is a common and temporary condition. It is usually not a cause for concern and typically self-resolves. However, staying informed about neonatal breast engorgement can help you manage the condition better and provide appropriate care to your newborn. Read the infographic below for more information about neonatal breast engorgement and its essential features.

facts about neonatal breast swelling (infographic)

Illustration: Momjunction Design Team

Key Pointers

  • Swollen breasts in newborns are a common occurrence and may not cause harm.
  • It is usually the result of hormones and may produce a milk-like fluid in babies.
  • It is a temporary condition and resolves spontaneously after a few weeks.
  • Pinching the baby’s swollen breasts may cause infection.
  • Medical attention is warranted if the baby has persistent swelling or a high fever.
swollen breast in newborn_illustration

Image: Stable Diffusion/MomJunction Design Team


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
  1. V Raveenthiran; (2013); Neonatal Mastauxe (Breast Enlargement of the Newborn).
  2. Hormonal effects in newborns.
  3. Swollen breasts.
  4. Hormonal effects in newborns.
  5. Swollen Genitals (Infants).
  6. Breast Symptoms-Child.
  7. Nahar AL Ruwaili and Dennis Scolnik; (2012); Neonatal Mastitis: Controversies in Management.
  8. Endocrinology Referral Guidelines Children’s Specialty Group.
Was this article helpful?
Like buttonDislike button
Dr. Wayne Hough
Dr. Wayne HoughMBChB, MMed, FC Paeds
Dr. Wayne Hough is a pediatrician with around six years of experience in the field. He is currently based in the Northern Suburbs of Cape Town in South Africa. Dr. Hough got his medical degree from the University of Stellenbosch.

Read full bio of Dr. Wayne Hough
Jessica Albert is a passionate writer who seeks to connect with her readers through wit and charm. Her work aims to invoke curiosity and keep the readers engaged through and through. She has two years of experience working with magazines and e-commerce establishments as a content marketer and editor.

Read full bio of Jessica Albert
Rebecca is a pregnancy writer and editor with a passion for delivering research-based and engaging content in areas of fertility, pregnancy, birth, and post-pregnancy. She did her graduation in Biotechnology and Genetics from Loyola Academy, Osmania University and obtained a certification in ‘Nutrition and Lifestyle in Pregnancy’ from Ludwig Maximilian University of Munich (LMU).

Read full bio of Rebecca Malachi
Anindita Ghatak holds a B.Tech degree in Biotechnology from Amity University, Kolkata. During the course of her studies, she has worked on different research projects in the fields of Microbiology and Bioinformatics. Anindita has over three years of experience writing medical articles for journals.

Read full bio of Anindita Ghatak