Last updated: March 2, 2026 by Maria Gonzalez

Healthy Weight Gain During Pregnancy

Formula

Recommended gain based on pre-pregnancy BMI category per IOM guidelines; gain is roughly linear over 40 weeks

The Institute of Medicine (IOM) provides weight gain recommendations based on pre-pregnancy BMI. Underweight women should gain more, while overweight women should gain less.

IOM guidelines: Underweight (BMI <18.5): 12.5-18 kg; Normal (18.5-24.9): 11.5-16 kg; Overweight (25-29.9): 7-11.5 kg; Obese (30+): 5-9 kg. Consult your OB for personalized guidance.

Common use cases:

  • Monitoring healthy pregnancy weight gain
  • Discussing weight goals with healthcare provider
  • Understanding BMI-based recommendations

Frequently Asked Questions

MG

Maria Gonzalez

Registered Dietitian, RD, MPH

Maria is a Registered Dietitian with a Master's in Public Health. She focuses on evidence-based nutrition assessment tools including BMI, calorie calculations, and body composition analysis.

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