Neonatal jaundice and fatty acid composition of the maternal diet

Breast Milk Constituents and the Development of Breast Milk Jaundice in Neonates: A Systematic Review

Breast milk is tailored for optimal growth in all infants; however, in some infants, it is related to a unique phenomenon referred to as breast milk jaundice (BMJ). BMJ is a type of prolonged unconjugated hyperbilirubinemia that is often late onset in otherwise healthy-appearing newborns, and its occurrence might be related to breast milk itself. This review aims to systematically evaluate evidence regarding breast milk composition and the development of BMJ in healthy neonates. PubMed, Scopus and Embase were searched up to 13 February 2023 with key search terms, including neonates, hyperbilirubinemia, and breastfeeding. A total of 678 unique studies were identified and 12 were ultimately included in the systematic review with narrative synthesis. These included studies covered both nutritional compositions (e.g., fats and proteins) and bioactive factors (e.g., enzymes and growth factors) of breast milk and formally assessed the difference in the concentration (or presence) of various endogenous components of breast milk collected from mothers of BMJ infants and healthy infants. The results were inconsistent and inconclusive for most of the substances of interest, and there was only a single study available (e.g., total energy and mineral content, bile salts and cytokines); conflicting or even contradictory results arose when there were two or more studies on the subject matter (e.g., fats and free fatty acids contents and epidermal growth factor). The etiology of BMJ is likely multifactorial, and no single constituent of breast milk could explain all the BMJ cases observed. Further well-designed studies are warranted to investigate the complex interaction between maternal physiology, the breast milk system and infant physiology before this field could be progressed to uncover the etiology of BMJ.

Human milk fatty acid profile across lactational stages after term and preterm delivery: A pooled data analysis

BACKGROUND

Lipids in human milk (HM) provide the majority of energy for developing infants, as well as crucial essential fatty acids (FA). The FA composition of HM is highly variable and influenced by multiple factors. We sought to increase understanding of the variation in HMFA profiles and their development over the course of lactation, and after term and preterm delivery, using a pooled data analysis.

OBJECTIVE

To review the literature and perform a pooled data analysis to qualitatively describe an extensive FA profile (36 FAs) in term and preterm colostrum, transitional - and mature milk up to 60 days postpartum.

DESIGN

A Medline search was conducted for HMFA profile data following term or preterm delivery. The search was confined to English language papers published between January 1980 and August 2018. Studies reporting original data, extensive FA profiles in HM from healthy mothers were included. Weighted least squares (WLS) means were calculated from the pooled data using random or fixed effect models.

RESULTS

Our pooled data analysis included data from 55 studies worldwide, for a total of 4374 term milk samples and 1017 preterm milk samples, providing WLS means for 36 FAs. Patterns in both term and preterm milk were apparent throughout lactation for some FAs: The most abundant FAs (palmitic, linoleic and oleic acid) remained stable over time, whereas several long-chain polyunsaturated FAs (including ARA and DHA) seemed to decrease and short- and medium-chain FAs increased over time.

CONCLUSIONS

High heterogeneity between individual studies was observed for the reported levels of some FAs, whereas other FAs were remarkably consistent between studies. Our pooled data suggests that specific FA categories fluctuate according to distinct patterns over the course of lactation; many of these patterns are comparable between term and preterm milk.

Macro- and Micronutrients of Human Milk Composition: Are They Related to Maternal Diet? A Comprehensive Systematic Review

BACKGROUND

This study aims at systematically reviewing the observational and interventional studies on the association of maternal macro- and micronutrient intake with breast milk content.

METHODS

We systematically searched the Medline via PubMed, Scopus, and ISI Web of Knowledge till October 2016 with the following search strategy: ("human milk" OR "breast milk" OR "breast milk composition" OR "human breast milk composition" OR "composition breast milk" OR "mother milk" OR "human breast milk") AND ("maternal diet" OR "maternal nutrition"). We also searched Google scholar for increasing the sensitivity of our search. The search was not limited to title and abstract due to the possibility that the desired outcome might have been considered a secondary aim. We excluded conference papers, editorials, letters, commentary, short survey, and notes. The search was refined to English language, and we did not consider any time limitation. To increase the sensitivity and to select more studies, the reference list of the published studies was checked as well.

RESULTS

This review included 59 observational and 43 interventional studies on maternal diet related to breast milk composition. Different studies determined the associations and effects of some maternal dietary intake of micro and macronutrients and its reflection in human milk.

CONCLUSION

Maternal dietary intake, particularly fatty acids, and some micronutrients, including fat soluble vitamins, vitamin B₁, and vitamin C, was related to their content in breast milk composition.

Impact of maternal nutrition on breast-milk composition: a systematic review

BACKGROUND

It is widely reported that maternal diet influences the nutritional composition of breast milk. The amount of variability in human milk attributable to diet remains mostly unknown. Most original studies that reported a dietary influence on breast-milk composition did not assess diet directly, did not quantify its association with milk composition, or both.

OBJECTIVE

To gather the quantitative evidence on this issue, we carried out a systematic PubMed and Medline search of articles published up to January 2015 and filtered the retrieved articles according to predefined criteria.

DESIGN

Only studies that provided quantitative information on both maternal diet and milk data, measured in individual healthy mothers of healthy term infants and based on an original observational or experimental design, were included. Exclusion criteria were a focus on supplements, transfer of toxic metals or other contaminants from diet to milk, or on marginally nourished women.

RESULTS

Thirty-six publications-including data on 1977 lactating women-that matched our criteria were identified. Seventeen studies investigated dietary effects on fatty acids in breast milk. The rest included studies that focused on a diverse spectrum of other nutritional properties of breast milk. The largest evidence, in terms of number of articles, for any link between maternal diet and a nutritive property of breast milk came from 3 studies that supported the link between fish consumption and high docosahexaenoic acid in breast milk and 2 studies that reported a positive correlation between dietary vitamin C and milk concentrations of this vitamin.

CONCLUSIONS

The available information on this topic is scarce and diversified. Most of the evidence currently used in clinical practice to make recommendations is limited to studies that only reported indirect associations.

Breast milk jaundice and maternal diet with chinese herbal medicines

Our objective was to identify the association between maternal diet with Chinese herbal medicines and prolonged jaundice of breast-fed infants. Healthy infants at 25 to 45 days of age were eligible for enrollment into this prospective study. Jaundice was defined as a transcutaneous bilirubin (TcB) value ≥ 5 mg/dL. A questionnaire survey asking feeding type, stool pattern, and maternal diet was conducted at the time of TcB measurement. A total of 1148 infants were enrolled, including 151 formula-fed, 436 combination-fed, and 561 breast-fed infants. The incidences of jaundice were 4.0% in formula-fed infants, 15.1% in combination-fed infants, and 39.8% in breast-fed infants (P < 0.001). In addition, jaundice was noted in 37.1% of preterm infants and 25.0% of term infants (P < 0.001). Furthermore, jaundice was more common in breast-fed infants whose mothers did not consume the traditional Chinese herbal medicines than in breast-fed infants whose mothers did consume such medicines (P < 0.001). In conclusion, this cohort study has identified late-preterm birth and breast feeding as the contributory factors for prolonged jaundice of apparently well infants. The data indicate that postpartum diet with Chinese herbal medicines is associated with breast milk jaundice.

Does breast feeding influence liver biochemistry?

OBJECTIVE

It is assumed that early feeding can affect liver biochemistry because breast-fed infants have a higher risk of hyperbilirubinemia than formula-fed infants. The authors sought to determine how feeding mode affected liver biochemistry in healthy term infants.

METHODS

Healthy term infants were followed up during infancy with a monthly questionnaire about feeding mode. Blood samples were obtained at 2, 6, and 9 months. Liver biochemistry (serum albumin, alkaline phosphatase, lactic dehydrogenase, aspartate aminotransferase [AST], and bilirubin), total insulin-like growth factor 1 (IGF-I), and insulin growth factor binding protein 3 (IGFBP-3) were determined at all ages.

RESULTS

Mean AST and bilirubin were significantly higher in breast-fed infants at 2 and 6 months. In addition, mean albumin levels were higher in breast-fed infants at 2 months. Alkaline phosphatase, IGF-I, IGFBP-3, and lactic dehydrogenase levels did not differ between the feeding groups. AST levels did not correlate significantly with bilirubin, albumin, alkaline phosphatase, or lactic dehydrogenase values. There was a strong positive association between AST and IGF-I at 2 months (r = 0.47, P = 0.004).

CONCLUSION

Cytomegalovirus infection, vitamin K deficiency, and macromolecular forms of AST could be an explanation for a higher AST level among breast-fed infants. However, no other clinical or paraclinical sign of liver disease was seen, all infants were given oral vitamin K, and the AST did not rise to levels comparable to those seen in individuals with macromolecular AST. The authors speculate the most likely explanation of the elevated AST is induction of hepatocytes by factors in human milk. This is supported by the higher albumin levels in breast-fed infants and the positive association between AST and IGF-I.

Human milk in disease: lipid composition

Differences in the lipid composition of human milk have been described in maternal diseases known to affect fat metabolism. Diseases such as diabetes, cystic fibrosis, hypobetalipoproteinemia and Type I hyperlipoproteinemia affect the quantity and quality of human milk fat. Increased fatty acid chain elongation and changes in desaturation (especially delta 6 desaturase), as well as changes in lipid class composition, have been shown in diabetes and cystic fibrosis, whereas compensatory increases in medium-chain fatty acids have been described in hypobetalipoproteinemia and Type I hyperlipoproteinemia. It is important to realize that these observations were made either on single women or on very small groups of women. In infant diseases, such as breast milk jaundice and ectopic eczema, changes in polyunsaturated fatty acids in maternal milk have been described.

Breastfeeding and breast milk jaundice

Two Types of jaundice associated with breast-feeding are recognized. The first type is early onset breastfeeding jaundice which may result from caloric deprivation and/or insufficient frequency of feeding. This type of jaundice can be prevented or treated by encouraging mothers to nurse as frequently as possible, particularly if the bilirubin level is rising. The second type is later onset, prolonged jaundice, known as the breast milk jaundice syndrome which is associated with one or more abnormalities in the maternal milk itself. Breast milk jaundice syndrome generally needs no therapy if serum bilirubin concentrations remain below 270 mumol/l in healthy full-term infants. When the serum bilirubin concentration is above 270 mumol/l and rising, temporary interruption of breastfeeding may be indicated.