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Mammary glands in newborns
Last reviewed: 04.07.2025

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The mammary glands of newborns develop in a special way in utero and after birth, so it is very important to distinguish between the features of the physiological process and the onset of the disease. Parents are always worried about the health of their little child, so any changes in the mammary glands worry them. But this is not always so serious, so first of all, it is the parents who need to know when exactly it is worth contacting a doctor.
Features of the mammary glands in newborns
When a child develops inside the tummy, regardless of whether it is a boy or a girl, many factors of the mother's body affect it. If the future child is a boy, then he has a certain amount of testosterone, a male sex hormone, which is secreted in small quantities by the adrenal glands of the baby itself, as well as by the woman's body. These hormones ensure the development of the genitals according to the male type and the formation of brain structures. If there is a girl in the mother's womb, then the main part of the sex hormones are female. But both the boy and the girl are affected by the mother's sex hormones - estrogens and progesterone, which are synthesized by the adrenal glands, ovaries, and placenta. Therefore, the mammary glands and genitals of a newborn child in the first month of life may have some features of structure and development.
The anatomy of the mammary glands in newborns is such that they continue to develop after birth. The gland itself has the same structure in girls and boys. It consists of glandular tissue, loose connective tissue and milk ducts. In newborns, the mammary gland lies on a large "fat pad" that consists of connective tissue with a loose structure. The milk ducts themselves are not very developed, but they have a small branching in the radial direction.
Physiological changes in the mammary glands of newborns develop because the mother had a lot of estrogens that affected the fetus. This may simply be because their amount is greater than required, or they are excessive for a boy. Then estrogens are able to affect the milk ducts and the number of muscle fibers increases. Due to the characteristics of such a large connective tissue layer, which acts as a "cushion", the ducts cannot increase and go deep, but they increase "under the skin". This phenomenon is a normal physiological change.
The peculiarities of the influence of estrogens in utero on the fetus can also be the secretion of colostrum. Some milk ducts are capable of secreting a secretion under the influence of excess hormones, which in its composition is colostrum. Therefore, if a newborn child secretes a secretion from the mammary glands during the first month of life, this can also be a physiological phenomenon.
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Diseases of the mammary glands in newborns
In order not to harm the child, you need to clearly understand when changes in the mammary glands in newborns are considered normal, and when it is already a disease.
Problems with the mammary glands in infants most often begin in the second week of the child's life. The symptoms that appear at this time and indicate physiological changes do not change the general condition of the child. The main criterion is that the child's appetite is preserved, sleep is not disturbed, he gains enough weight, the stool is normal, and there are no signs of intoxication. The enlargement of the mammary glands in newborns and their engorgement occurs gradually, usually on both sides. At the same time, the breast increases evenly up to three centimeters. Such swelling of the mammary gland is not accompanied by reddening of the skin and this does not bother the child. If you try it with the mother's hands, then such compaction of the child's breast is not dense, uniform, and the child does not cry or react when palpated. Discharge from the mammary glands in newborns can be in the form of a serous transparent or slightly whitish fluid. Such symptoms are characteristic not of a disease, but of the normal process of a sexual crisis in a child, which can develop in all children. This process does not last more than two weeks, and by the end of the first month of life, all these symptoms gradually disappear.
Speaking about physiological engorgement of the mammary glands in newborns, it is necessary to understand that this pathology occurs in 75% of all children. More often these are girls, of course, but 50% of newborn boys are also subject to such processes. Therefore, you should not panic if such phenomena occur, you just need to consult a doctor and make sure that everything is fine.
But the symptoms of diseases that can also occur at this age need to be clearly known and differential diagnostics carried out.
The first symptoms that should alert you are the appearance of anxiety in the child, screaming or refusal to breastfeed. If the child had engorgement of the mammary glands and everything was normal, but suddenly he began to lose weight or refuse the breast with a piercing cry, then you need to think about the disease. Often the disease develops at the end of the first month of the child's life, when physiological swelling should pass, then an infection can join and mastitis can develop. Mastitis is an inflammation of the mammary gland in an infant, which equally occurs in girls and boys. Given the same anatomical features of the mammary gland of a small child, loose connective tissue contributes to the immediate spread of inflammation deep into the body, so the child's condition immediately worsens with the development of mastitis. A child is not inclined to limit the inflammatory process as an adult is inclined. Therefore, the main symptom of an inflammatory disease of the mammary gland of a newborn is a very high temperature. It rises very sharply with mastitis and can be accompanied by convulsions. When examining the mammary gland, the mother can see not only its enlargement, but also a change in the skin, redness or even a blue tint. If you try the baby's breast, he will react immediately, as it is accompanied by severe pain. If an abscess has formed, you can feel how the pus moves under your fingers during palpation. This process is usually one-sided. Discharge can also be from the nipple on the affected side in the form of green or yellow pus. But you should not torment the baby too much and check all the symptoms, if you have any doubts, it is better to consult a doctor. Therefore, the main diagnostic sign of not a physiological condition, but a disease of the mammary gland in newborns is a change in the child's condition.
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Treatment of mammary gland diseases in newborns
The main treatment for physiological engorgement of the mammary glands is rest. You should not interfere with any folk remedies, ointments or tinctures, since this is a normal process that will pass on its own. On the contrary, persistent intervention can lead to the development of complications. Often, parents, in order to speed up the process of resolving the swelling of the mammary glands, massage or squeeze colostrum out of the nipple. This should never be done, because additional intervention is a risk factor for skin damage, which, even if small, can be an entry point for infection. Therefore, the main recommendations for parents with such physiological compaction of the mammary glands are as follows:
- provide the child with maximum peace;
- feeds, bathes, walks, just like with a healthy baby;
- Do not rub or use any ointments on the chest area;
- Do not massage or use heating pads.
If everything is normal, the symptoms will go away on their own within one to two weeks.
If we are talking about a breast disease in newborns such as mastitis or an abscess, then the tactics are completely different. Immediately after the diagnosis is made, the child is immediately hospitalized in the pediatric surgical department. Today, given the speed of spread of the infectious process in the body of a newborn child, the tactics of treating mastitis or an abscess are active. No ointments or drugs are used for conservative therapy. The main principles of treatment in this case are the extraction of the pathological focus as soon as possible and active antibacterial therapy. Therefore, first of all, the child undergoes surgery. Under general anesthesia, an operation is performed urgently. The scope of the operation consists of making incisions on the skin of the affected area of the mammary gland in a checkerboard pattern. There can be a large number of them, which depends on the volume of the affected gland. The incisions are made in such a way that they are located on the border of healthy and affected skin. Then drains are installed, through which active washing of such an area is carried out. Then the drains are left for better outflow of pus. Dressings need to be done after the operation several times a day and the mother should monitor this. Feeding such a child continues as usual with breast milk, which provides better protection for the child.
Against the background of such surgical intervention, massive antibacterial therapy is mandatory. Now it is recommended to use even three antibiotics with different spectrums of action for treatment, with two of them used parenterally (into a vein), and one enterally (taken in suspension). Only with such active actions can complications of mastitis be avoided.
These are the main approaches to the treatment of physiological engorgement and inflammation of the mammary glands in newborns.
The mammary glands of newborns are always exposed to sex hormones in utero, so breast compaction can often be seen as normal in infants. This does not cause any other symptoms on the part of the child, so it does not require additional interventions. But it is important to remember that inflammation can also occur, so every mother should be attentive to her child.