Sample FAQ: Causes of low milk supply from birth (failure of lactation)

The following is one FAQ (frequently-asked question) of 600. There are 25 more FAQs on the topic of a low milk supply from birth and others about losing your milk (reduced milk supply), milk coming in late, how to increase your milk supply, and how to supplement a baby with extra milk. 

Why have I never had enough milk?

There are many reasons why a mother may have a low milk supply from birth. They fall into five groups: (1) problems related to labour or delivery; (2) hormonal problems; (3) breast problems such as surgery or lack of development; (4) illness in the mother around the time of delivery; and (5) genetic conditions. Some mothers with a low supply don’t have any of these conditions. Some mothers will always have a low milk supply, but others, particularly those whose problems are related to delivery, may have a full supply with the next baby. Some mothers worry that they have a low milk supply because they are not eating or drinking enough or are getting too little sleep. Those are rarely the cause of a low supply.

A) Reasons for never having had enough milk

While most mothers have a normal milk supply, some mothers may notice that their milk comes in late. Others may never have enough milk.

Please work with your health-care providers if you feel that you do not have enough milk.

Possible reasons for a low milk supply fall into five groups.

1) Causes of low milk supply related to labour or delivery

2) Causes of low milk supply related to hormonal problems

3) Causes of low milk supply related to breast problems

4) Causes of low milk supply related to illness in the mother around the time of delivery

5) Causes of low milk supply related to genetic conditions

  • Abnormality in how zinc is handled by cells (zinc transporter [ZnT2]) (Lee et al. 2018; Kelleher et al. 2019; Rivera et al. 2020)
  • Abnormal prolactin or prolactin receptors (Golan and Assaraf 2020)

B) Unknown reasons for not having enough milk

We have found that some mothers who have never had enough milk do not have any of the above conditions. There is a small amount of evidence that the mother’s genetics, diet, and environmental toxins may prevent the normal development of the breast. Research continues (Lee and Kelleher 2016).

C) Milk supply with the next baby

Some mothers, particularly those with insufficient glandular tissue or who have had extensive breast surgery, will have a low milk supply with each baby. Other mothers, particularly those who have had problems related to delivery, may have a full milk supply with the next baby.

D) Other concerns

Some mothers worry that they have a low milk supply because they are not eating or drinking enough or are getting too little sleep. Unless a mother is severely underfed or malnourished, the quality and supply of her milk should be normal.

References

Bjelakovic L, Trajkovic T, Kocic G, et al. The Association of Prenatal Tocolysis and Breastfeeding Duration. Breastfeed Med. 2016 Dec;11:561-563

Golan Y, Assaraf YG. Genetic and Physiological Factors Affecting Human Milk Production and Composition. Nutrients. 2020 May 21;12(5):E1500

Kelleher SL, Gagnon A, Rivera OC, et al. Milk-derived miRNA profiles elucidate molecular pathways that underlie breast dysfunction in women with common genetic variants in SLC30A2. Sci Rep. 2019 Sep 3;9(1):12686
 
Lee S, Kelleher SL. Biological underpinnings of breastfeeding challenges: the role of genetics, diet, and environment on lactation physiology. Am J Physiol Endocrinol Metab. 2016 Aug 1;311(2):E405-22
 
Lee S, Zhou Y, Gill DL, et al. A genetic variant in SLC30A2 causes breast dysfunction during lactation by inducing ER stress, oxidative stress and epithelial barrier defects. Sci Rep. 2018 Feb 23;8(1):3542

Rivera OC, Geddes DT, Barber-Zucker S, et al. A common genetic variant in ZnT2 (Thr288Ser) is present in women with low milk volume and alters lysosome function and cell energetics [published online ahead of print, 2020 Apr 22]. Am J Physiol Cell Physiol. 2020;10.1152/ajpcell.00383.2019