Maternal anthropometry predicts benefit in lactational performance of undernourished Guatemalan women

Is Maternal Body Weight or Composition Associated with Onset of Lactogenesis II, Human Milk Production, or Infant Consumption of Mother's Own Milk? A Systematic Review and Meta-Analysis

Maternal adiposity impacts lactation performance, but the pathways are unclear. We conducted a systematic review to understand whether maternal adiposity (body mass index [BMI] or percentage fat mass) is associated with onset of lactogenesis II (copious milk; hours), human milk production (expressed volume/24 h), and infant consumption of mother's own milk (volume/24 h). We used random-effects standard meta-analyses to compare the relative risk (RR) of delayed lactogenesis II (>72 h) between mothers classified as underweight (BMI <18.5 kg/m2), healthy weight (BMI, 18.5-24.9 kg/m2), and overweight/obese (BMI ≥25 kg/m2) and random-effects meta-regressions to examine associations with hours to lactogenesis II and infant milk consumption. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. We included 122 articles. Mothers with underweight (RR: 0.64; 95% CI: 0.49, 0.83; I2 = 39.48%; 8 articles/data points) or healthy weight status (RR: 0.67; 95% CI: 0.57, 0.79; I2 = 70.91%; 15 articles/data points) were less likely to experience delayed lactogenesis II than mothers with overweight/obesity. We found no association between maternal BMI and time to onset of lactogenesis II (β: 1.45 h; 95% CI: -3.19, 6.09 h; P = 0.52, I2 = 0.00%; 8 articles, 17 data points). Due to limited data, we narratively reviewed articles examining BMI or percentage fat mass and milk production (n = 6); half reported an inverse association and half no association. We found no association between maternal BMI (β: 6.23 mL; 95% CI: -11.26, 23.72 mL; P = 0.48, I2 = 47.23%; 58 articles, 75 data points) or percentage fat mass (β: 7.82 mL; 95% CI: -1.66, 17.29 mL; P = 0.10, I2 = 28.55%; 30 articles, 41 data points) and infant milk consumption. The certainty of evidence for all outcomes was very low. In conclusion, mothers with overweight/obesity may be at risk of delayed lactogenesis II. The available data do not support an association with infant milk consumption, but the included studies do not adequately represent mothers with obesity. This study was registered in PROSPERO as 285344.

Antibodies to Escherichia coli and Shigella flexneri in milk from undernourished mothers: studies on sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated antigens

Analysis of IgA, IgM, and IgG antibodies against Escherichia coli O6, its lipopolysaccharide (LPS), and Shigella flexneri were performed in the milk of moderately undernourished Guatemalan women receiving either a low or a high calorie supplement, using SDS-PAGE. As expected, the immunostaining analysis of milk antibodies showed that IgA was the predominant isotype in both groups. Concerning the other Igs, antibodies against O6 LPS were mainly of the IgM isotype, whereas IgG antibodies were more prominent than IgM against the bacterial whole cell preparations. Seven to nine distinct bands, ranging in molecular mass from 13.5 to 109 kD were selected for each antigen to compare the milk antibodies between the two groups of women. After a 20-wk supplementation period, the IgA and IgG antibodies to the E. coli, O6 LPS, and S. flexneri were not found negatively affected by a low calorie intake. A significantly lower immunostaining intensity was, however, obtained for the low calorie intake group regarding the IgM antibody activity against four high molecular mass bands of the E. coli whole cell preparation. A decreased immunostaining intensity was also found in the same group for IgM antibodies against two bands of E. coli O6 LPS when analyzing paired samples collected at d 0 and wk 20. No differences were found for IgM antibodies against any of the S. flexneri antigens. In conclusion, the results suggest that low calorie intake does not significantly affect the production of milk IgA antibodies to E. coli and S. flexneri antigens in these women. Still, IgM antibodies against certain proteins and LPS molecules of E. coli may be decreased. IgG antibodies, although also present in milk, seemed to be directed mainly against bacterial proteins and not to LPS.