Maternal Diet Influences Fetal Growth but Not Fetal Kidney Volume in an Australian Indigenous Pregnancy Cohort.

Eugenie R Lumbers,Yu Qi Lee,Tracy L Schumacher,Clare E Collins,Kirsty G Pringle,Kym M Rae

doi:10.3390/nu13020569

Abstract

Suboptimal nutrition during pregnancy is recognised as a significant modifiable determinant in the development of chronic disease in offspring in later life. The current study aimed: (i) to assess the dietary intakes of pregnant Indigenous Australian women against national recommendations and (ii) to investigate the associations between maternal nutrition during pregnancy and the growth of the offspring, including kidney development in late gestation in the Gomeroi gaaynggal cohort (n = 103). Maternal dietary intake in the third trimester was assessed using the Australian Eating Survey Food Frequency Questionnaire. Estimated fetal weight (EFW) and kidney size were obtained by ultrasound. Birth weight was retrieved from hospital birth records. Of the five key nutrients for optimal reproductive health (folate, iron, calcium, zinc and fibre), the nutrients with the highest percentage of pregnant women achieving the nutrient reference values (NRVs) were zinc (75.7%) and folate (57.3%), whereas iron was the lowest. Only four people achieved all NRVs (folate, iron, calcium, zinc and fibre) important in pregnancy. Sodium and saturated fat intake exceeded recommended levels and diet quality was low, with a median score of 28 out of 73 points. After adjusting for smoking and pre-pregnancy body mass index, only maternal intake of retinol equivalents and the proportion of energy from nutrient-dense or energy-dense, nutrient-poor (EDNP) foods were associated with fetal growth. EFW decreased by 0.13 g and birth weight decreased by 0.24 g for every µg increase in maternal dietary retinol intake. Interestingly, EFW, but not actual birth weight, was positively associated with percentage energy from nutrient dense foods and negatively associated with percentage energy from EDNP foods. Dietary supplement usage was associated with increased birthweight, most significantly iron and folate supplementation. Current dietary intakes of pregnant Australian women from this cohort do not align with national guidelines. Furthermore, current findings show that maternal retinol intake and diet composition during pregnancy can influence fetal growth, but not fetal kidney growth in late gestation. Strategies that aim to support and optimise nutrient intakes of Indigenous pregnant women are urgently needed. Future studies with long-term follow-up of the children in the current cohort to assess renal damage and blood pressure are imperative.

Highlights

Maternal dietary intake influences the supply of nutrients required for optimal fetal growth, and so potentially has life-long impacts for offspring’s future health [1,2].Events such as the Dutch Famine of 1844–1945 [3] highlighted the association between malnutrition during pregnancy and birth weight
This study used data collected from the Gomeroi gaaynggal study, a prospective longitudinal cohort of Indigenous Australian mother–child dyads followed from pregnancy, through the postnatal period and up until the children are 10 years of age
The current analysis shows that pregnant Indigenous women may benefit from a higher diet quality and that targeting the intakes of key micronutrients important for perinatal and long-term child health would be of value

Summary

Introduction

Maternal dietary intake influences the supply of nutrients required for optimal fetal growth, and so potentially has life-long impacts for offspring’s future health [1,2]. Events such as the Dutch Famine of 1844–1945 [3] highlighted the association between malnutrition during pregnancy and birth weight. Nutrient inadequacies during pregnancy can impair fetal growth, which can in turn increase risk for low birth weight (LBW), small-for-gestational-age (SGA) or preterm delivery [4,5,6] or alterations in infant body composition [7]. Maternal protein restriction in pregnancy is associated with reduced birth weight, impaired nephron endowment, elevated blood pressure and reduced glomerular filtration rate (GFR)

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