Preemie Breastfeeding: The Holy Grail of NICU

Jae Kim, MD, PhD / February 2019

In Scandinavian countries like Sweden, the breastfeeding rates across their population are enviably one of the best in the Western world (~52% exclusive breastfeeding at 4 months). They also provide their mothers with generous maternity leave (16 months compared to our optional 3 months in the U.S., in Finland it is ~40 months). They have had cultural norms of breastfeeding that makes breastfeeding more visible.

Together those conditions allow mothers to be just that: mothers. Breastfeeding is ultimately an easier choice. In the middle of the night, the ease of having nutrition immediately available cannot be beaten.

However, pumping breast milk for our preemie mothers is a necessity. The Scandinavian success of breastfeeding extends into the NICU, and revolves around depending on their mothers to participate in bedside care, and staying longer hours with their infants which promotes bonding, all positive factors to their breastfeeding success.

In the U.S., we are more challenged by our lower breastfeeding rates and the lack of societal support for adequate maternity leave. We set higher goals and are on the way to increasing our baseline breastfeeding rates each year towards the goals set for Healthy People 2020 (such as exclusive breastfeeding at 3 months of 46%).

Ideal breastfeeding requires that mother-baby bonding to occur from birth and continue throughout the first few months of life. That is not the case for preemies. Most preemie nutrition focuses on the provision of mother’s milk and to a lesser degree on breastfeeding. Providing pumped milk for the duration of the hospital stay is what keeps infants on the best track of life. A lofty goal for all preemies would be to ultimately attain exclusive breastfeeding.

Breastfeeding NICU Babies

Can our preemies successfully breastfeed long-term? If we break it down to major determinants, breastfeeding requires two things: a mother and a baby. A mother needs to be willing, able, and available, and baby needs to be willing and capable.

Most mothers are willing and able. For preterm infants, most mothers state a desire to provide milk and breastfeed their preterm infants, but there is a long wait time to reach that milestone. For a 24-weeker, it may be closer to 3 to 4 months before a mother can have that opportunity. That obviously poses a challenge. While preemie mothers are at higher risk of lower milk production and having reduced lactation periods, it may not be as much biology as it is a function of the challenges of pumping in a stressful period of time when their baby is born.

The most successful preemie lactation support programs suggest that strongly. Asking mothers to produce for longer than their term counterparts is a lot to ask. Still, I see mothers of preemies as special individuals, whose calling as mothers has pushed them to be more determined in supporting what their babies need. They have witnessed the power of mother’s milk in protecting their infants from disease and bowel catastrophes, and may be more vested in continuing to pump despite the prolonged effort.

Unfortunately, many mothers are not available enough. Obviously, they are there for birth and shortly thereafter, but our system provides too many opportunities to exclude mothers from participating in their infant’s care for too long in any day. We make it easy for mothers to stay away most of the time, and the competing factors of transportation, other children, etc. create further significant barriers. By the time breastfeeding is possible, they do not have the habit of staying for long durations of time.

The training time for breastfeeding is much longer than with term infants who are naturally ready for oral feeding. Breastfeeding the preemie starts alongside a slower and more erratic progression of success with any type of oral feeding. Timing feeds with the feeding schedule and being “called off” occurs frequently.

Preemie Feeding Challenges

One big impediment to success is that preemies are not capable for a long time. While they are hungry from the get go, they demand enormous amounts of nutrients for growth and development. Preemies start universally willing to feed but somewhere down the line this falls off in certainty.

The challenges with very small preemies are many, not the least being the lengthy time it takes for preterm infants to figure out how to swallow correctly. It is through a long process of training over a period of several weeks, sometimes months, to learn how to feed by mouth. Each infant is unique, and each works out their own kinks to command over 40 muscles in the mouth and throat to coordinate an organized suck and swallow. If they get it wrong, they can aspirate milk into their lungs and compromise their breathing.

Gastroesophageal reflux is a significant nemesis here, too. Most preterm infants have some degree of gastroesophageal reflux. Many of them successfully manage their symptoms and work around the reflux events. For some, this becomes an increasing problem as they feed larger volume as they grow. We do not have an effective treatment for moderate reflux disease. We attempt to control some symptoms with feeding regimen, frequency, positioning of infants, thickening of feeds, and acid blocking medicine. We have much more caution now using the latter two treatments with associated warnings of harm. For severe reflux disease, we invoke drastic measures such as surgical fundoplication.

Preterm infants are at high risk of getting their feeding patterns wrong. They can learn improper ways to suck and poor avoidant behaviors with feeding. Then, for some, the willingness to get onto the breast is lost or extremely frustrating, and far more difficult than taking from the bottle. We are rushed due to finances to send infants home as soon as they are safely feeding enough by mouth. What that means is that almost all infants in our system can only achieve minimal breastfeeding (1-2 per day) before they are sent home to work on breastfeeding more.

Even the parents are understandably complicit in this, as they are eager to go home, but weight gain is a key determinant of discharge. Inefficient feeding such as when breastfeeding is being established can lead to poor weight gain, and that adds a huge stress to mothers.

How Can We Improve Breastfeeding in the NICU?

Looking to Sweden helps us identify cultural norms that support breastfeeding, at least within the NICU. Mothers should be expected more and more to spend a majority of their time in the NICU. Single patient room design is facilitating, but not driving this change. Change in culture needs to happen first. Most importantly we need to decide that preemie breastfeeding is an important goal to attain, whether within the walls of the NICU or at home. If we want to achieve this in-house, then we may need to change the expectations of timing of discharge (i.e. longer length of stay). If we expect this to take place at home, then the support system in the community needs to be available to help mothers achieve it.

When we were building our SPIN program, we kept setting one of our goals to be more like Sweden. We wanted to capture the success of Sweden in the area of preemie breastfeeding. Their preterm birth rate is less than half what it is in the US, at 5% compared to our 11% (or more). They have had impressive success with preemie breastfeeding, but the most recent data from the Swedish registry of their NICUs suggest some disturbing trends.1 Over the period between 2004 and 2013, Sweden has seen a significant decline in their preemie breastfeeding rates. In their smallest preemie category (22 to 27 weeks gestation), their exclusive breastfeeding rates dropped from 55% to 16%; the more mature cohorts declined to a lesser extent. The authors speculated on the factors at play, such as changes in social culture, increased emphasis on fortification of mother’s milk, and single family rooms, but also that other unmeasured factors were likely at play. We should all be concerned that Sweden is experiencing a downward trend in their preemie breastfeeding rates.

So where are our sticking points, and how do we achieve this lofty goal of preemie breastfeeding? What do we need to do to break this barrier?

The two weakest points are that mothers aren’t available enough, and infants are not programmed to be capable and willing to breastfeed, and too often are pushed to lose willingness such as with feeding aversion.

Socially we would need to advocate for longer maternity leave. We are one of the last developed countries to not mandate maternity leave. This will take time, and clearly this is not the only driver of preemie breastfeeding. One promising light comes from independent companies that have taken it upon themselves to provide improved parental leave. Now we need to wait for the tipping point with other industries.

Finding solutions is going to be unique for us in America, but having a good understanding of what we expect and consider success is key to achieving this mission. With enough collective determination, even this holy grail of the NICU can be found!

I leave you several practice points to consider:

  • Educate all stakeholders of the problem!
  • Have more mommy time (other cuddlers count too)
  • Families and peer-to-peer support to help mothers stay on their mission to sustain milk production
  • Put babies to breast early for non-nutritive sucking
  • Lactation support by all professionals
  • Proper lactation space and equipment (electric pumps, nipple shields, etc.)
  • Optimally grow babies to have the capacity to orally feed
  • Cue based feeding standards and teaching (lots of work needed here)
  • Increase training with expertise to improve feeding performance
  • Set an actual goal of higher breastfeeding at time of discharge
  • Increased community support for breastfeeding preemies


  1. (
  2. Ericson J, Flacking R, Hellström-Westas L, Eriksson M. Changes in the prevalence of breast feeding in preterm infants discharged from neonatal units: a register study over 10 years. BMJ Open. 2016 Dec 13;6(12):e012900. doi: 10.1136/bmjopen-2016-012900. PubMed PMID: 27965252; PubMed Central PMCID:PMC5168690.

About the Author

Jae Kim is an academic neonatologist and pediatric gastroenterologist and nutritionist at UC San Diego Medical Center and Rady Children’s Hospital of San Diego. He has been practicing medicine for over 23 years both in Canada and the USA. He has published numerous journal articles, book chapters, and speaks nationally on a variety of neonatal topics. He is the Director for the Neonatal-Perinatal Medicine Fellowship Program at UC San Diego and the Nutrition Director of an innovative multidisciplinary program to advance premature infant nutrition called SPIN (Supporting Premature Infant Nutrition, He is the co-author of the book, Best Medicine: Human Milk in the NICU. Dr. Kim is a clinical consultant with Medela LLC.