Maternal low birth weight and hypertensive disorders of pregnancy

Objectives: To investigate the association between maternal own low birth weight (<2500 g) and subsequent risks for hypertensive disorders of pregnancy (HDP) and preeclampsia. Study design: 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]. Main outcome measures: 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. Results: 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. Conclusion: 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.