# Maternal hypertension and telomere length are associated with weight for age Z score change from birth to 6 months of age in a predominantly Latinx cohort

## TL;DR

This study finds that maternal hypertension and longer telomeres in newborns are linked to changes in infant weight growth up to six months of age.

## Contribution

The novel contribution is identifying maternal hypertension and telomere length as factors associated with infant weight gain in a Latinx cohort.

## Key findings

- Maternal hypertension is associated with increased weight for age Z score change in infants.
- Longer leukocyte telomere length at birth is positively linked to greater weight gain in the first six months.
- Birthweight Z score is inversely associated with rapid infant weight gain and weight change.

## Abstract

Weight gain in the first six months of life is a predictor of future obesity with rapid infant weight gain (RIWG) (change > 0.67 SD in weight for age Z score from birth to 6 months of age), a strong predictor for obesity at age 5.

We recruited a multi-racial birth cohort of primarily Latinx mothers and newborns at two San Francisco hospitals. Dried blood spots were taken from infants for leukocyte telomere length (LTL) analysis. Multivariable models were used to evaluate risk factors for RIWG, weight for age Z score (WAZ) change and WAZ at 6 months including gestational and/or pre-existing hypertension and LTL. Separate models were run for term infants ( > = 37 weeks).

Slightly over one third of infants (35.76%) had RIWG (total N = 330). Hypertension in pregnancy and/or pre-existing hypertension (OR 2.16, 95%CI 1.05–4.45) and birthweight Z score (OR 0.42, 95%CI 0.28–0.63) were associated with RIWG. Similarly, maternal hypertension was positively and birthweight Z score was negatively associated with WAZ score change (Coeff = 0.37, 95%CI 0.08–0.70; Coeff=-0.47, 95%CI -0.61-(-)0.34 respectively). LTL at birth was also positively associated with WAZ score change (Coeff = 0.41, 0.04–0.78). Birthweight Z score was associated with WAZ score at 6 months (OR 0.55795%CI 0.43–0.71) as was maternal hypertension (Coeff = 0.36 (95% CI, 0.06–0.66)).

In our primarily Latinx cohort, there were similar risk factors for RIWG and WAZ change from birth to 6 months of age. Pre-existing and/or gestational hypertension was associated with RIWG and WAZ change. Longer LTL at birth may be a marker of greater WAZ change.

The online version contains supplementary material available at 10.1186/s12884-025-08213-8.