NICU Milk Warmers: How Many is Enough?

Meredyth Thompson, BSN, RN / July 2018


Has this happened to you?

It is a very busy morning and I am running late for the first feeds of the day. I hurry to the prep room down the hall and find I have no milk in the fridge for my patient. I run to the freezer, set some milk to thaw in the row of milk warmers nearby, and head off to care for my first patient.

Shortly after, I run back to the prep area to grab my milk, only to notice that someone has removed my thawed milk and commandeered the warmer for their own purposes. Thankfully, I find my thawed milk in the fridge and set about to prepare the feed.

I am now ready to warm my feeding, but, to my dismay, the four warmers are all in use for other patients. I notice there is still quite a bit of time on the timers, but I need to warm now before my day gets any farther behind. I resort to our old stand-by: cup and water method. I know this is not the best way to warm the milk. I know using this method will degrade the properties of this breast milk, and also introduces a risk for waterborne bacteria contamination… but I’m in a time crunch, and the warmers are all in use. Frustrated, I continue with this method and move on with my day.

Later in my day, I’ve caught up and start my last round of cares early. I go to the prep room and prep milk for two different patients. I place the feedings in separate warmers and go on to care for my first baby. When I go back to get the milk for this patient, who happened to have a name alert, I realize the syringe is not in warmer I put it in! What? Where did my milk go? Maybe someone brought it to my bedside and we crossed paths. It’s not uncommon for a tech or a charge nurse to do this for us.

I go to my bedside, and it’s definitely not there. I start to get nervous and frustrated. Where is my milk?  I call the techs and charge nurse and ask if they have it. Unfortunately, they do not! I don’t have time to track it down right now, so I head back to the prep room and start prepping my feed again. As I’m pulling up my milk for the second time, I happen to glance at the patient label. I remember this baby has a name alert. He has a similar name to another patient on the unit. I suddenly realize that my first syringe could be at the other baby’s bedside. Oh no!

I go to find that baby and that nurse and begin to tell her what happened. I see her face go white. She steps quickly to her baby’s bedside and stops the feeding. She had milk warming at the same time I did, and a pod mate who was headed to the prep area asked them to grab her syringe. When the syringe didn’t scan, she overrode the scanner because the label was wrinkled, and she thought that was the issue. We both panic and immediately call the charge nurse and practitioner to tell them what happened. We had a breast milk misadministration!

Milk warming: A reality check

Now, you may be reading this and think this story is just that, a story.  Unfortunately, these are real events from real NICUs.

They impacted real patients, real nurses, and real families.  I’m happy to say that these patients were not harmed by these issues. However, there were psychosocial effects for the families and the nurses involved in these situations.

When you take a step back and dissect the feeding process, from preparation to administration, you will find there are many pitfalls along the way that could trap any provider. In those scenarios, the review process revealed that more equipment was needed to ensure a warming process milk misadministration would not occur again.

NICU milk warming considerations

Here are some considerations to determine equipment needs, especially when it comes to warmers:

  1. Consider the nursing or tech workflow. Is the equipment placed in a convenient location to allow easy access, within a few steps from the patient’s bedside? If space is a barrier, consider a pole mount for the warmer, or consider an inline warming device.
  2. Consider nursing efficiency. How can you assist your staff in completing the feeding task in an efficient manner? Providing a warmer for every patient would be ideal, and one for every two babies would be the next best scenario.
  3. Lastly, you may also consider the ratio of feeder/ grower babies versus larger chronic babies, or ill babies that may not be eating. These babies require various amounts of feeding volume and may need more, or less time to thaw and warm milk. Additionally, consider the length of time to thaw other human milk products, i.e. donor milk, etc.

It is always best to evaluate your facilities human milk process from beginning to end to ensure that the risk for misadministration is mitigated, and your staff are set up for success in their work. There are some wonderful resources listed below(1-7) that can assist you in this process.

I am passionate about the safety of human milk administration and have followed the recommendations above in my own units to create efficient systems for adherence to warming policies and practices. When we provide the right resources and support to our staff, there is an increase in their satisfaction, an increase in efficiency, and ultimately, we are able to do what is best for our babies.


Learn more about the Medela Waterless Milk Warmer and the Guardian Warmer.



  1. Bondurant, P., Nielsen-Farrell, J., Armstrong, L., (2015) The Journey to High Reliability in the NICU. Journal of Perinatal and Neonatal Nursing. (29)(2). 170-178
  2. Doerhoff, R, Garrison, B. (2015). Human Factors in the NICU: A Bedside Nurse Perspective. Journal of Perinatal and Neonatal Nursing. (29)(2) 162-169.
  3. Drenckpohl, D., Bowers, L., Cooper, H., (2007). Use of the Six Sigma Methodology to Reduce Incidence of Breast Milk Administration Errors in the NICU. Neonatal Network. (26)(3).161-165.
  4. Flanagan, K. (2016). Wrong Route Error in the NICU: Protecting Patients and Practitioners. Neonatal Intensive Care. (29)(3). 15-16.
  5. Luton, A. Bondurant, P., Campbell, A., et al. (2015). Got (the Right) Milk? Advances in Neonatal Care. (15)(5). 345-353.
  6. Zeilhofer, U, Bernhard, F, Zandee, J. (2009). The Role of Critical Incident Monitoring in Detection and Prevention of Human Breast Milk Confusions. Journal of Pediatrics.
  7. Zhang, B, LaFleur, E, Ballweg, D, et al. (2014). Use of Healthcare Failure Mode and Effect Analysis (HFMEA)to Quantify Risks of the Human Milk Feeding Process. Journal of Nursing Care Quality. (29)(1). 30-37.


About the Author

Meredyth Thompson, BSN, RN, is a Clinical NICU Specialist with Medela. She has 13 years of NICU experience where she was a staff nurse, travel nurse, and nurse manager. She has experience working in a variety of NICU’s across the nation including large children’s hospitals and small and large delivery centers. She has a passion for developmental care, human milk, nurse mentorship, nurse manager coaching, and is a powerful change agent. Meredyth has been trained in Lean Management Systems and has thorough experience in NICU design and expansion project management.