1 - Egas Moniz Higher Education School, Instituto Universitário Egas Moniz, Centro de Investigação Interdisciplinar Egas Moniz (CiiEM, U4585 FCT), Applied Nutrition Studies Group (G.E.N.A.- IUEM), Monte de Caparica, Portugal.
2 - Nutrition Unit, Maternidade Dr. Alfredo da Costa, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal.
3 - Research Unit, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal.
4 - Neonatal Intensive Care Unit, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal.
5 - Neonatal Intensive Care Unit, Maternidade Dr. Alfredo da Costa, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal.
6 - Prenatal Diagnosis, Maternidade Dr. Alfredo da Costa, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal.
7 - Comprehensive Health Research Centre (CHRC), Medicine of Woman, Children, and Adolescent, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.
- American Journal of Perinatology 2023;40(2):163-171. doi: 10.1055/s-0041-1727278.
Objective: To assess the association between intrauterine growth of preterm infants and energy and macronutrient contents in their mothers’ milk.
Study design: A historical cohort of mothers of preterm infants was assessed according to offspring’s intrauterine growth. Fetal growth restriction was defined as small-for-gestational age or appropriate-for-gestational age with fetal growth deceleration. During the first four weeks after delivery, the composition of daily pool samples of mothers’ milk was measured using a mid-infrared human milk analyzer. Explanatory models for milk energy, true protein, total carbohydrate, and fat contents were obtained by generalized additive mixed effects regression models.
Results: 127 milk samples were analyzed from 73 mothers who delivered 92 neonates. Energy content was significantly higher in mothers with chronic hypertension (average +6.28 kcal/dL; 95% CI: 0.54, 12.01; p=0.034) and for extremely preterm compared to very preterm infants (average +5.95 kcal/dL; 95% CI: 2.16, 9.73; p=0.003), and weakly associated with single pregnancies (average +3.38 kcal/dL; 95% CI: 0.07, 6.83; p=0.057). True protein content was significantly higher in mothers with chronic hypertension (average +0.91 g/dL; 95% CI: 0.63, 1.19; p<0.001) and with hypertension induced by pregnancy (average +0.25 g/dL, 95% CI: 0.07; 0.44; p=0.007), and for extremely preterm compared to very and moderate preterm infants (average +0.19; 95% CI: 0.01, 0.38; p=0.043 and +0.28 g/dL; 95% CI: 0.05, 0.51; p=0.017, respectively). Fat content was weakly and negatively associated to fetal growth restriction, both in small-for-gestational-age infants and appropriate-for-gestational-age infants with fetal growth deceleration (average -0.44 g/dL; 95% CI -0.92, -0.05; p=0.079 and average -0.36 g/dL; 95% CI -0.74, -0.02; p=0.066, respectively).
Conclusions: Energy and macronutrient contents in mothers’ milk of preterm infants was significantly and positively associated with the degree of prematurity and hypertension. The hypothesis that the composition of milk is associated with fetal growth restriction was not demonstrated.
Palavras-Chave: fetal growth restriction, maternal hypertension, mothers’ milk composition, prematurity, twin pregnancy