Mothers' Breastmilk May Improve Preterm Babies' Heart Health

Baby breastfeeding

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Key Takeaways

  • A new study finds that a mother’s breastmilk can improve her preterm baby’s cardiac health.
  • Preterm babies who had their mother’s milk had the heart function similar to a full-term baby at the one-year mark.
  • The findings are promising, but more research is needed to determine the long-term impact.

Preterm babies can encounter more health challenges than babies born full-term. Intellectual disabilities, developmental delays, and problems with the brain, lungs, and even heart can affect infants born significantly earlier than 37 weeks. But a new study offers encouraging news in the heart development of a preterm child.

The study published in the Journal of the American Medical Association finds that preterm infants who were fed their mother’s milk had a significant improvement in their cardiac function at the one-year mark. The news is encouraging for the parents of preterm babies and health professionals seeking to give the little ones a healthier start in life.

Brenda Poindexter, MD

Preterm milk is uniquely designed by nature to support a preterm baby.

— Brenda Poindexter, MD

Details from the Study

Researchers analyzed data from infants who were taking part in a larger project, the Prematurity and Respiratory Outcomes Program at the Washington University School of Medicine. Eighty babies born earlier than 29 weeks participated in the study from 2011 to 2013.

Infants who were provided breastmilk from their own mother for at least 28 days of the study period were referred to as part of the high mother’s milk group. Babies who received their mother’s breastmilk for less than 28 days, and received formula or donor’s milk to supplement, were considered the low mother’s milk group.

Echocardiograms were done on the babies at 32 weeks and at 36 weeks. They were done again at the corrected one-year mark (the point when an infant would have been one year old if they had been born full-term). Investigators were able to take measurements of the heart as well as assess its utility.

After they culled the data, researchers learned that babies who were a part of the high mother’s milk group experienced improved cardiac function after a year. In fact, their heart performance approached that of babies the same age who were born full-term.

While the findings are promising, there are some study limitations. The data were gathered as a part of post-hoc analysis. Researchers were studying other topics but were able to pull the information to create this secondary observational study.

In addition, the testing only looked at short-term results on the infants. It is not known whether the improvements made by the breastmilk feedings will translate into reversing the long-term cardiac issues.

Strengthening Preterm Babies' Hearts

Investigators acknowledge the study's weaknesses but note the potential benefit derived from the findings.

Because preterm infants’ hearts may not have been able to form properly before leaving the womb, they may experience heart valve blockages or septal abnormalities. They can also have a greater risk of congenital heart disease.

The findings of the study don’t attempt to say that a mother’s breastmilk can alleviate these issues. But the infants who had higher doses of their mom’s own milk had a stronger cardiac performance. Researchers don’t exactly understand how the milk caused the improvement, but experts say its properties seemed to contribute to improving the babies’ heart health.

“Preterm milk is uniquely designed by nature to support a preterm baby," explains Brenda Poindexter, MD, MS, System Medical Director for Neonatology at Children’s Healthcare of Atlanta. "But there are also a host of non-nutritional factors that are in human milk—like human milk oligosaccharides, which are sort of the specialized carbohydrates that are unique to every single mother. [It also includes] things like growth factors and hormones, immunoglobins, and lactoferrin, which is a powerful anti-inflammatory."

The study authors think this information can give parents of preterm babies a little bit of hope. “Despite the data that [a preterm baby's] heart pumps a little bit less and [that these babies] tend to have heart problems more than the general population, there are some things we can do from the beginning itself which may change the outcome,” states Amish Jain, PhD, MBBS, MRCPCH, one of the authors of the study, a staff neonatologist at Mount Sinai Hospital, and the director of the Targeted Neonatal Echocardiography and Hemodynamic Program.

Amish Jain, PhD

Despite the data that [a preterm baby's] heart pumps a little bit less and [that these babies] tend to have heart problems more than the general population, there are some things we can do from the beginning itself which may change the outcome.

— Amish Jain, PhD

Giving Babies What They Need

Delivering a baby preterm is not only stressful for the child but difficult and painful for the parent as well. Grace and patience are needed as parents work to recover physically, mentally, and emotionally, as well as help their babies continue to develop. Whether you are using a formula, donor’s milk, or mother’s breast milk, simply feeding a baby is the most important thing.

The study highlights the fact that if mothers are able to provide their preterm baby the beneficial nutrients that their breastmilk has to offer, their infants may grow stronger now and in the future.

What This Means For You

The study's findings provide a bit of hope to parents who are concerned about their preterm baby’s cardiac development. Just keep in mind that if you are not able to breastfeed your baby, you don’t need to feel guilt or shame. A fed baby is a loved baby.

4 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cleveland Clinic. Premature Birth.

  2. El-Khuffash A, Lewandowski AJ, Jain A, Hamvas A, Singh GK, Levy PT. Cardiac performance in the first year of age among preterm infants fed maternal breast milk. JAMA Netw Open. 2021;4(8):e2121206. doi:10.1001/jamanetworkopen.2021.21206

  3. University of California San Francisco; Department of Surgery. Patent ductus arteriosus.

  4. Steurer MA, Baer RJ, Keller RL, et al. Gestational age and outcomes in critical congenital heart disease. Pediatrics. 2017;140(4):e20170999. doi:10.1542/peds.2017-0999

By LaKeisha Fleming
LaKeisha Fleming is a prolific writer with over 20 years of experience writing for a variety of formats, from film and television scripts, to magazines articles and digital content. She has written for CNN, Tyler Perry Studios, Motherly, Atlanta Parent Magazine, Fayette Woman Magazine, and numerous others. She is passionate about parenting and family, as well as destigmatizing mental health issues. Her book, There Is No Heartbeat: From Miscarriage to Depression to Hope, is authentic, transparent, and providing hope to many.Visit her website at