Maternal body mass index and child haemoglobin: A national cross-sectional study in Peru

Childhood anaemia remains a major public health problem in Peru. Although several maternal and environmental factors have been implicated, the association between maternal body mass index (BMI) and anaemia in young children remains inconsistent. This study aimed to evaluate the association between maternal BMI and both anaemia and haemoglobin levels in children aged 6-59 months in Peru.

We conducted a cross-sectional analytical study using data from the 2024 Peruvian Demographic and Family Health Survey. Children aged 6-59 months and their mothers were included. Maternal BMI was the exposure variable, while childhood anaemia and haemoglobin concentration were the outcomes. Poisson regression was used to estimate prevalence ratios for anaemia, and linear regression models were applied to assess associations with haemoglobin levels.

A total of 16,973 children were analysed. In adjusted analyses, maternal BMI categories were not associated with anaemia prevalence. However, maternal obesity, compared to normal weight, was associated with higher haemoglobin levels in children (adjusted β 0.72 g/dL; 95% CI 0.23 to 1.22). Additionally, each 1 kg/m2 increase in maternal BMI was associated with a 0.07 g/dL increase in child haemoglobin (adjusted β 0.07; 95% CI 0.03 to 0.11).

Maternal body mass index was not associated with the prevalence of anaemia, although a positive association was observed with child haemoglobin levels. These findings support the inclusion of maternal nutritional status within comprehensive anaemia prevention strategies and highlight the need for longitudinal studies to confirm these associations.