TĂNG CÂN THAI KỲ, BMI TRƯỚC MANG THAI VÀ NGUY CƠ SINH CON ≥ 4 KG: TỔNG QUAN TƯỜNG THUẬT

Abstract

pregnancy body mass index (BMI) and gestational weight gain (GWG) with the risks of macrosomia (birthweight ≥4,000 g) and large-for-gestational-age (LGA; >90th percentile for gestational age and sex), to evaluate the suitability of Asian BMI cut-offs, and to summarize Vietnam-specific data.

Methods: A narrative review prioritizing systematic reviews/meta-analyses, cohort studies, and clinical guidelines reporting quantitative estimates. GWG was categorized as below/within/above the 2009 Institute of Medicine (IOM) recommendations by BMI group.

Results: Pre-pregnancy overweight/obesity is consistently associated with higher risks of macrosomia and LGA; several cohorts report that each 1 kg/m² increase in BMI is linked to an approximately 13–24% higher macrosomia risk. Meta-analyses indicate that GWG above IOM ranges increases the risk of macrosomia (OR≈1.95) and LGA (OR≈1.85) compared with GWG within recommendations; for example, women with normal BMI are advised to gain 11.5–16 kg. Asian BMI thresholds (overweight ≥23.0; obesity ≥27.5 kg/m²) may improve risk stratification in Asian populations. In Vietnam, evidence is largely hospital-based, suggesting a substantial burden of birthweight ≥4,000 g, but heterogeneity in outcome definitions and confounder adjustment highlights the need for standardization and local validation of GWG targets.

Conclusion: Higher pre-pregnancy BMI and excessive GWG are consistent, modifiable risk factors for fetal overgrowth; optimizing preconception weight, providing structured GWG counseling based on IOM guidance (with consideration of Asian BMI cut-offs), and achieving effective glycemic control especially in gestational diabetes may reduce macrosomia/LGA.