Expected Weight Changes After Birth for Term Breastfed Newborns
by Anne Eglash MD, IBCLC, FABM
We know that nearly all newborns lose weight during the first few days of life. Concerns regarding weight loss often lead to supplementation, which in some cases is appropriate, and in other cases not. The authors of this week’s CQW performed a systematic review of recent evidence to evaluate current guidelines suggesting caution when weight loss reaches 7% of birthweight. The authors explain that the 7% recommendation came from studies that did not follow infants long enough to see the true nadir of weight loss. In addition, some of the infants in the studies were not breastfed.
The authors searched the literature published in 2015-2019 to explore the expected amount of neonatal weight loss in healthy term infants. They found 11 studies that met their eligibility criteria, but only 3 of the studies included any weights after hospital discharge. In some of the studies, infants were excluded if they were started on supplementation due to weight loss.
The authors of this systematic review concluded that mean weight loss on day 2 was 6-7%, and 7-8% on day 3. These stats included both vaginal and cesarean births.
There are so many factors that determine infant weight loss, such as maternal IV fluids intrapartum, birth trauma, cesarean birth, delay in lactogenesis, maternal illness, insufficient glandular tissue, infant sleepiness, timing of the first feeding, and neonatal jaundice, among many others. There was no consistency across these studies as to the exclusion of any of these conditions.
- Weight loss was generally found to be greater on day 3 than day 2.
- The majority of the infants in the included studies were back to birthweight between 10-14 days postpartum.
- In several studies, weight loss of 7% or greater in the hospital was associated with significantly less exclusive breastfeeding by day 14.
- The studies did not have consensus on whether peak weight loss occurs on days 2, 3, or 4 after birth.
See the Answer
To summarize the findings of recent studies on neonatal weight changes that occur in the early weeks of life among full-term, breastfed newborns.
Using the keywords breastfeeding, newborn, infant, weight, weight loss, and growth, we searched PubMed, Cumulative Index of Nursing and Allied Health Literature, Cochrane Library, and MEDLINE for primary studies and secondary analyses. We also reviewed the reference lists of retrieved articles.
Quantitative studies published in the English language from 2015 through 2019 that focused on newborn weight changes. From a total of 827 records initially screened, we included 11 studies in this analysis.
Two authors independently reviewed the selected articles with the use of the Johns Hopkins Nursing Evidence-Based Practice Synthesis and Recommendations Tool. To determine evidence levels and quality ratings, we evaluated the consistency and generalizability of study results, sample sizes, study designs, adequacy of controls, and definitive nature of the conclusions.
By 2 days after birth, mean weight loss among neonates was 6% to 7% of birth weight, and by Day 3, mean weight loss was usually 7% to 8%. The nadir of lost birth weight occurred on Days 2, 3, or 4 after birth. At times, breastfed newborns lost 10% or more of their birth weight. By 10 to 14 days, most newborns regained their birth weight. Rates of exclusive breastfeeding decreased when newborns lost greater amounts of weight. Compared with past studies, more sample groups in this review included exclusively breastfed newborns and weight assessments beyond birth hospitalization.
Weight loss is commonly 7% to 8% of birth weight or greater by the third day after birth among healthy, full-term, breastfed newborns.
The bottom line here is that our research on infant weight loss postpartum is not strong. Older recommendations by the American Academy of Pediatrics suggested that 7% weight loss ought to rouse concern, but we know from this review that weight loss on day 3 was higher, often up to 8%. We all witness newborns reaching 10% weight loss by day 3, yet for many of these dyads, breastfeeding is going well, milk supply is rapidly increasing at that time, so supplementation is not necessary, vs other dyads for which supplementation is absolutely needed.
Many physicians, nurses and other providers who care for newborns are now relying on the NEWT tool to determine appropriateness of infant weight loss. The data for this tool is based on 143,889 infants who were 36 weeks gestation or older, 63% exclusively breastfed. Infants with health problems not requiring level II or III neonatal unit care were not excluded. They found that the average nadir of weight loss was 5.9% at 61 hours after a vaginal birth, and 7.1% at 68 hours for a cesarean birth. The problem here is that more than 1/3 of the infants received supplementation, and many were late preterms. This tool basically describes a population, but does not set a standard. Because of the quality of its data, it cannot indicate when to supplement.
A true weight loss standard would be based on a population of 100% exclusively breastfed healthy infants, born 39-40 weeks gestation who have no complications such as jaundice. Their mothers would not be at risk for a delay in lactation or other reasons for insufficient milk supply. To this date, we still do not have this kind of data. We don’t have a ‘magical’ weight loss number that tells us when to supplement. Every breastfeeding dyad needs professional management over a period of time until weight gain cadence is appropriate, and breastfeeding is perceived as going well by mom and her supporters. This means that if healthcare professionals are making decisions on supplementation, it is critical that they gain sufficient knowledge on this healthcare topic, and follow the dyad as closely as they do for any other medical problem that requires close follow up.