Maternal low birth weight and hypertensive disorders of pregnancy

To investigate the association between maternal own low birth weight (<2500 g) and subsequent risks for hypertensive disorders of pregnancy (HDP) and preeclampsia.

A multicenter retrospective study was conducted using clinical data from 12 primary maternity care units from 2012 to 2018. A total of 17,119 women with information about their own birth weight, who delivered at term, were subdivided into four groups according to maternal birth weights [(<2500, 2500-3499, 3500-3999, and ≥4000) g].

Multivariate regression analyses were conducted to evaluate the risks for HDP and preeclampsia among women born with low birth weight compared with women born with a birth weight of 2500-3499 g. We evaluated these risks, stratified by pre-pregnancy BMI or their infants' birth weight categories.

Maternal low birth weight was an independent risk factor for HDP after adjustment for several covariates, but not for preeclampsia. A 100-g increase in maternal birth weight was associated with a 3% risk reduction for HDP. Additionally, women born with low birth weight had the highest risk for HDP among those with a pre-pregnancy BMI of ≥25 kg/m². Conversely, women born with high birth weight (≥4000 g) had the highest risk for preeclampsia if they complicate with fetal growth restrictions.

Women born with low birth weight had an increased risk for HDP. Collection of information on maternal birth weight may facilitate the prediction of HDP and patients' self-awareness of such risk, allowing the modification of lifestyle factors associated with HDP.