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

Amanda V Montana; Alison Mildon; Allison I Daniel; Michael A Pitino; Jo-Anna B Baxter; Megan R Beggs; Sharon L Unger; Deborah L O'Connor; Kathryn Walton

doi:10.1016/j.advnut.2024.100228

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

Adv Nutr. 2024 Apr 11:100228. doi: 10.1016/j.advnut.2024.100228. Online ahead of print.

Authors

Amanda V Montana¹, Alison Mildon², Allison I Daniel³, Michael A Pitino¹, Jo-Anna B Baxter², Megan R Beggs¹, Sharon L Unger⁴, Deborah L O'Connor⁵, Kathryn Walton⁶

Affiliations

¹ Translational Medicine, The Hospital for Sick Children, Toronto ON, Canada; Department of Nutritional Sciences, University of Toronto, Toronto ON, Canada.
² Department of Nutritional Sciences, University of Toronto, Toronto ON, Canada.
³ Independent consultant, Toronto, ON, Canada.
⁴ Department of Nutritional Sciences, University of Toronto, Toronto ON, Canada; Paediatrics, Mount Sinai Hospital, Toronto ON, Canada; Division of Neonatology, The Hospital for Sick Children, Toronto ON, Canada.
⁵ Translational Medicine, The Hospital for Sick Children, Toronto ON, Canada; Department of Nutritional Sciences, University of Toronto, Toronto ON, Canada; Paediatrics, Mount Sinai Hospital, Toronto ON, Canada.
⁶ Translational Medicine, The Hospital for Sick Children, Toronto ON, Canada; Department of Family Relations & Applied Nutrition, University of Guelph, Guelph, ON, Canada. Electronic address: kwalton@uoguelph.ca.

PMID: 38609047
DOI: 10.1016/j.advnut.2024.100228

Abstract

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: 0.61; 95% CI: 0.46, 0.83; I² = 46.27%; 8 articles/data points) or healthy weight status (RR: 0.72; 95% CI: 0.61, 0.84; I² = 64.41%; 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 onset of lactogenesis II (β: 1.45 h; 95% CI: -3.19, 6.09 h; P = 0.52, I² = 0.00%; 8 articles, 15 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: 5.84 mL; 95% CI: -11.92, 23.60 mL; P = 0.51, I² = 44.18%; 58 articles, 75 data points) or percentage fat mass (β: 6.54 mL; 95% CI: -3.60, 16.68 mL; P = 0.20, I² = 21.40%; 30 articles, 32 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.

Keywords: breastfeeding; human milk; lactogenesis; maternal body composition; maternal body mass index.

Publication types

Review