{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T19:13:20Z","timestamp":1760037200789,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T00:00:00Z","timestamp":1755216000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Introduction: Several factors can affect the composition of a mother\u2019s milk, including the infant\u2019s sex, gestational age, and single or twin delivery. We aimed to determine the association of the offspring\u2019s sex with the macronutrient and energy content in preterm milk, during the first six weeks postpartum. Methods: This is a retrospective, monocentric, cohort study of lactating mothers who delivered before 37 weeks at a referral tertiary maternity. A mid-infrared human milk analyzer was used. Results: From 174 mothers, 360 milk samples were obtained. In the milk for singletons, the mature milk for females was significantly richer in total energy, fat, and protein than the milk for males; in advanced lactation, the milk for males was richer in protein than the milk for females. The transitional milk for male twins was significantly richer in fat and energy than the milk for male singletons; mature milk for male twins was richer in energy, carbohydrates, and protein than the milk for singletons. The mature milk for female twins during the fourth week postpartum was significantly richer in fat and total energy than the milk for singletons. Conclusions: This study provides information on how the number of delivered fetuses and the infant\u2019s sex affects the composition of preterm milk.<\/jats:p>","DOI":"10.3390\/nu17162644","type":"journal-article","created":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T10:33:42Z","timestamp":1755254022000},"page":"2644","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Sexual Dimorphism in Preterm Milk: A Step Toward the Individualized Fortification of Mother\u2019s Own Milk?"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-6322-1252","authenticated-orcid":false,"given":"In\u00eas","family":"Rodrigues","sequence":"first","affiliation":[{"name":"Nutrition Laboratory, Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, 2829-511 Almada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8482-5936","authenticated-orcid":false,"given":"Lu\u00eds","family":"Proen\u00e7a","sequence":"additional","affiliation":[{"name":"Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, 2829-511 Almada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1175-1400","authenticated-orcid":false,"given":"Renata","family":"Ramalho","sequence":"additional","affiliation":[{"name":"Nutrition Laboratory, Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, 2829-511 Almada, Portugal"}]},{"given":"Daniel","family":"Virella","sequence":"additional","affiliation":[{"name":"Neonatology Unit, Maternidade Dr. Alfredo da Costa, Unidade Local de Sa\u00fade S\u00e3o Jos\u00e9, Centro Cl\u00ednico Acad\u00e9mico de Lisboa\u2014CCAL, 1069-089 Lisbon, Portugal"},{"name":"CHRC\u2014Comprehensive Health Research Centre, Nutrition Group, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6480-1048","authenticated-orcid":false,"given":"Lu\u00eds","family":"Pereira-da-Silva","sequence":"additional","affiliation":[{"name":"CHRC\u2014Comprehensive Health Research Centre, Nutrition Group, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"Medicine of Woman, Childhood and Adolescence Academic Area, NOVA Medical School, Universidade Nova de Lisboa, Centro Cl\u00ednico Acad\u00e9mico de Lisboa\u2014CCAL, 1169-056 Lisbon, Portugal"}]},{"given":"Manuela","family":"Cardoso","sequence":"additional","affiliation":[{"name":"Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, 2829-511 Almada, Portugal"},{"name":"Nutrition Unit, Maternidade Dr. Alfredo da Costa, Unidade Local de Sa\u00fade S\u00e3o Jos\u00e9, Centro Cl\u00ednico Acad\u00e9mico de Lisboa\u2014CCAL, 1069-089 Lisbon, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,15]]},"reference":[{"key":"ref_1","first-page":"e54888","article-title":"Impact of early nutrition interventions on the growth and development of preterm infants: A narrative review","volume":"16","author":"Alanazi","year":"2024","journal-title":"Cureus"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1665","DOI":"10.1007\/s00431-021-03950-2","article-title":"Improving long-term health outcomes of preterm infants: How to implement the findings of nutritional intervention studies into daily clinical practice","volume":"180","author":"Ruys","year":"2021","journal-title":"Eur. 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