Low Milk Supply: Impaired Lactation

Low milk supply or impaired lactation refers to difficulties in initiating and maintaining an adequate milk supply for breastfeeding. It can encompass both delayed lactogenesis (delayed onset of milk production) and insufficient lactation (inadequate milk production). This article will explore why this happens, and what you can do to manage it.


Low milk supply is a very stressful experience for new mothers. It is a condition where the production of milk (lactogenesis) is delayed or insufficient. Breast milk is important for the health of your newborn as it provides vital nutrients for growth and supports the development of their immune system. It is important to recognise low milk supply early so as to fulfil the child's nutritional needs and intervene in the recovery of breastfeeding, whether that be full or partial.1

Human breasts begin development in utero and continue to develop through puberty, reaching full maturation and function in late pregnancy to postpartum. The primary function of breasts is the production of milk, which is transported to the nipple. The breasts are composed of structural, glandular and fatty (adipose) tissue. Breast milk production occurs in alveoli within lobes of the mammary glands and is transported through ducts to the nipple.2 Lactogenesis is the scientific name for milk production and occurs in two stages. Lactogenesis starts during pregnancy and involves glandular growth and development. These processes are all triggered by hormones and mid-pregnancy signals the cause the glands to start producing milk. However, at this stage, an intermediate milk-like substance is produced. Breast milk is not produced until birth. In the second stage of lactogenesis, the breast milk changes frequently as its fat, protein and immunoglobulin contents fluctuate with the needs of the child.1

The processes of lactation and breastfeeding are both very complex. There are external factors, such as time spent with the infant, socioeconomic situation, and physical surroundings, that can play a role in the success of breastfeeding. Internal factors, like physical and mental health, body image, and intentions around breastfeeding, also play a part in the success or struggle of breastfeeding. 

Delayed lactogenesis

Delayed Lactogenesis occurs when production of milk by the mammary glands is not triggered at an appropriate time. The hormone prolactin is a key hormonal signal in lactation. Prolactin triggers the start of colostrum production, which is a yellowish fatty substance produced in mid to late pregnancy, and up to four days after birth, that acts as an intermediate of breast milk. It is perfect for a newborn as it is rich in cholesterol, enzymes, immunoglobulins, sodium, and calcium. Yet, it is produced in limited quantities.

The delay occurs at the stage where colostrum is changed to breast milk. This is typically triggered by a drop in progesterone and oestrogen and a rise in prolactin, oxytocin and glucocorticoids, marking the beginning of plentiful milk supply.1 Hormones can be triggered by external stimuli, for example a huge dose of oxytocin is released immediately following birth. This hormone is associated with trust and is the foundation for the mother-baby bond. This is one of the reasons why skin-to-skin contact post-delivery is so important.3 

Causes and risk factors

Other potential causes and risk factors for delayed lactogenesis include:

It is important to give your body the signs to keep producing milk. Expressing milk from an early stage, by breastfeeding or by manual means, can stimulate the breasts to continue generating more milk. The recommendation is to have at least 8 feedings in a 24-hour time period.

Symptoms and diagnosis

There are a number of signs to watch out for if you think you are at risk of delayed or low milk production. Risk assessment is the main way to determine if you may suffer from insufficient milk supply as there is no definitive diagnostic test. The following are signals of ineffective breastfeeding which may suggest delayed lactogenesis:4

  • If you notice your baby is losing weight after birth and reaches a loss of 7% body weight or continues weight loss after day 3 post birth 
  • While feeding, you can’t hear an audible swallow from the baby
  • Less than 6 wet nappies a day after day 4 postpartum 
  • Less than 3 stools a day after day 4 postpartum 
  • Your baby is irritable, restless, or unusually sleepy
  • No noticeable changes in your breasts after day 5
  • Constant nipple pain

These symptoms should be reported to a medical professional who will conduct a clinical lactation assessment and suggest available interventions. This may include a medical history and physical examination, evaluation of the infant's weight gain and behaviour, measuring milk supply, and an assessment of breastfeeding technique.3

Consequences for both mother and infant

Delayed lactogenesis can increase the risk of newborn weight loss, which may result in early supplementation and early weaning. This takes away all the incredible benefits breastfeeding provides a newborn. It has been shown that breastfeeding for the recommended minimum duration of 6 months reduces the risk of infectious disease, asthma, and allergies in children.5 


Treatment plans will be proactive in helping you reach your full lactation potential, which differs from person to person. Delayed lactogenesis can be effectively treated if caught early enough. A treatment plan could contain any of the following: 

  • Providing adequate nutrition via supplementation
  • Maximising breast stimulation and complete breast emptying 
  • Measuring baby’s milk intake during breastfeeding
  • Keeping a record of a feeding plan
  • Recognition of when full lactation potential is reached by measuring milk expression (using pumping equipment and tracking quantities)
  • Education, coaching and mental support for the mother

Unfortunately there are currently no medications on the market to stimulate breast milk production as pregnant and breastfeeding women are usually not included in clinical studies for their own safety. However, there has recently been more of a push to design safe and effective clinical trials in order to tackle the unmet need.6

Insufficient lactation

Insufficient lactation is the complete failure or inability to produce or deliver milk. 

Causes and risk factors

Similarly to delayed production, failed lactation has a number of risk factors:

The signs and diagnostic procedure are similar for both conditions but management and treatment may differ. The underlying cause will be the roadmap for treatment. If hormones are to blame, then rectification of this imbalance will need to occur before or alongside lactation stimulation.3


What is low milk supply?

Impaired lactation refers to difficulties in initiating and maintaining an adequate milk supply for breastfeeding. It can encompass both delayed lactogenesis (delayed onset of milk production) and insufficient lactation (inadequate milk production).

Why don’t I make enough milk?

Delayed lactogenesis can be caused by various factors, including:

  • Hormonal imbalances
  • Maternal health conditions (e.g., polycystic ovary syndrome)
  • Maternal obesity
  • Certain medications
  • Caesarean birth
  • Maternal stress
  • Ineffective breastfeeding practices in the early postpartum period

Insufficient lactation can result from a combination of factors, including:

  • Ineffective breastfeeding technique
  • Poor milk removal from the breast
  • Hormonal imbalances
  • Maternal health conditions (e.g., thyroid disorders)
  • Certain medications
  • Inadequate glandular tissue
  • Maternal stress
  • Insufficient breast stimulation

What are the signs and symptoms of low milk supply?

Signs of delayed lactogenesis include delayed or minimal breast changes during pregnancy, lack of fullness of the breasts after birth, and a delay in the appearance of mature breast milk. The infant may exhibit poor latch, inadequate weight gain, and signs of hunger and dehydration.

Can impaired lactation be prevented?

While not all cases of impaired lactation can be prevented, some strategies can help optimise breastfeeding success.

What is the emotional impact of impaired lactation?

Impaired lactation can lead to emotional distress for mothers, as they may feel guilty, inadequate, or frustrated. 


Low milk supply is caused by either the delayed or failed onset of the second stage of lactogenesis. Prevention is the best treatment and if you have any of the risk factors outlined in this article, let your health care provider know as early as possible. In many cases, full or partial lactation recovery can be achieved with the proper treatment plan. Breastfeeding is really important for your baby and low milk supply can also be a huge strain on new mothers mentally, causing a huge amount of stress. There are many options available to support you and your baby and it is advised to ask your healthcare professional for advice.


  1. Hurst NM. Recognizing and treating delayed or failed lactogenesis II. J Midwifery Womens Health 2007;52:588–94. https://doi.org/10.1016/j.jmwh.2007.05.005
  2. Macias H, Hinck L. Mammary Gland Development. Wiley Interdiscip Rev Dev Biol 2012;1:533–57. https://doi.org/10.1002/wdev.35
  3. Moore ER, Anderson GC, Bergman N, Dowswell T. Early skin-to-skin contact for mothers and their healthy newborn infants. Cochrane Database Syst Rev 2012;5:CD003519. https://doi.org/10.1002/14651858.CD003519.pub3
  4. Nommsen-Rivers LA, Chantry CJ, Peerson JM, Cohen RJ, Dewey KG. Delayed onset of lactogenesis among first-time mothers is related to maternal obesity and factors associated with ineffective breastfeeding1234. The American Journal of Clinical Nutrition 2010;92:574–84. https://doi.org/10.3945/ajcn.2010.29192
  5. Huang Y, Liu Y, Yu X, Zeng T. The rates and factors of perceived insufficient milk supply: A systematic review. Matern Child Nutr 2021;18:e13255. https://doi.org/10.1111/mcn.13255
  6. Spatz DL. Treatment of Low Milk Supply. MCN: The American Journal of Maternal/Child Nursing 2022;47:361. https://doi.org/10.1097/NMC.0000000000000867
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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