# Maternal mineral nutrition during early pregnancy and neonatal growth: findings from a China birth cohort study

## TL;DR

This study explores how maternal mineral intake during early pregnancy affects newborn growth in China, finding gender-specific effects of calcium and iron.

## Contribution

The study identifies gender-specific associations between maternal calcium and iron levels and neonatal growth outcomes.

## Key findings

- Higher maternal calcium levels were linked to lower risk of small-for-gestational-age infants.
- Maternal iron levels showed an inverted U-shaped relationship with male infant birth length.
- No significant effect of iron on female infant birth length was observed.

## Abstract

Neonatal growth holds great significance for lifelong health, but the effects of maternal mineral nutrition during pregnancy on neonatal growth remain unclear. This study aimed to investigate the associations of the maternal mineral nutrition including copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), and iron (Fe) during early pregnancy with neonatal growth.

A prospective cohort study was conducted in Xi’an, China, with a total of 5,629 mother-infant dyads. The study examined the non-linear relationship and threshold effects between minerals and neonatal growth using smoothed plots and two-piecewise regression models.

Every one-unit elevation in log-transformed Ca concentration was associated with a 97% (RR: 0.03, 95% CI: 0.01–0.80) lower risk of small-for-gestational-age (SGA). Maternal Fe concentration was associated with birth length of male infants in an inverted U-shaped curve. When Fe concentration was less than 7.24 mmol/L, a one-unit elevation in log-transformed Fe concentration was associated with a 3.23-cm higher birth length (95% CI: 0.13–6.32) in male infants. However, this relationship was not found in female infants.

Adequate maternal Ca and Fe in early pregnancy may benefit newborn growth and development, but the gender differences should also be considered. Vigilant monitoring and prompt remediation of maternal mineral deficiencies during early pregnancy are essential for optimizing neonatal health outcomes.