Why We Test Breast Milk - A Case Study

I’m often asked why it’s helpful to test breast milk—and one of the best answers is in addressing a very common issue: helping babies who aren’t gaining enough weight through breastfeeding.

It’s a common occurrence: a mom feels passionately about breastfeeding, but baby isn’t gaining enough weight; her pediatrician recommends formula to supplement and that’s the end of the story. But now that we can test breast milk for fat and calories, that story can be rewritten.

Here’s an example. Baby S’s birth and early days were normal in every respect, and he began breastfeeding with no issues. His mother was passionate about breastfeeding, but her son stopped gaining weight within two weeks of birth and started losing weight right before her eyes. He was referred to a pediatric gastroenterologist who recommended supplementing her breast milk with formula and prescribed medication to help with reflux symptoms. These are two of the most common responses from medical professionals to an inability to gain weight while breastfeeding.

Baby S’s mom expressed her concerns to me as her family doctor and we decided it was best to test her milk. Enter Lactation Lab. We tested mom’s milk when Baby S was 2-3 months old and found it to have 16 calories per oz, below the average infant formula level of 20 kcal per oz. Following the pediatric specialist’s recommendation, mom started supplementing baby’s milk with a formula equivalent to 22 kcal per oz.

After returning to work, mom noticed that she was more relaxed about nursing having accepted the fact that her son needed supplementation. Nonetheless, we continued to support mom in her journey to continue to breastfeed. After testing her milk, we placed her on specific supplements as well as goat’s rue and lactation-boosting cooking containing brewer’s yeast. Goat’s rue and brewer’s yeast can both increase milk supply.  She continued to take her prenatal vitamin as well as vitamin D 2000 IU a day, vitamin A 5000 IU a day and B12 1000 mcg daily.

Despite her reservations about some of the ingredients used in infant formulas, mom continued supplementing as recommended by the gastroenterologist. Given her reservations, we decided to follow the child’s growth more closely and weigh him every two weeks. She continue to supplement until he was 4 months old. She decreased gradually over a two-week period and stopped at 4.5 months of age.

We encouraged her to increase her calories by 500 per day and she was easily able to add 300-400 calories daily. We asked her to continue to pump as much as possible, though volume was not the issue.

We re-tested her milk when her son was 4.5 months old and it had increased to 19.75 kcal/oz, equivalent to the average infant formula. After stopping the formula supplementation, her son gained 11.5 oz in one month. He reached the 6th percentile for weight, more than doubling from below the 3rd percentile, as shown in the graph below. He met all developmental milestones and was thriving.

Mom will be starting to introduce Baby S to solid foods, and based on the fact that her vitamin A was on the low side she will be focusing on first foods that are rich in vitamin A such as squash and sweet potato. Because her B12 was also a little low she will introduce lentils next.

This journey speaks to what Lactation Labs is about. We live in a world of information and data and we used it to reassure this mom that she could optimize her child’s nutrition. Instead of thinking her milk was not good enough, we supported her to KNOW otherwise.

Now the fun part: her son is refusing a bottle and the leftover formula is put away in the earthquake kit - we are in California after all!


About the author: Stephanie Canale, M.D. and founder of Lactation Lab

Stephanie earned her undergraduate and medical degrees from McGill University. She completed her residency training in Family Medicine at UCLA, and then was a part of the teaching faculty at the UCLA Family Health Center before joining UCLA Santa Monica in 2010. She is a also a member of the American Board of Family Medicine.

As a mother of two, she has a profound passion for helping families. Dr. Canale is a tireless advocate for moms and babies, on a constant quest to develop tools and support for families of all backgrounds and income levels.


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