Educational tool — not a diagnosis. VivMetric calculators estimate body and fitness metrics using CDC, WHO, and NIH reference formulas. They do not provide medical advice, diagnosis, or treatment.
Always consult a licensed healthcare provider for medical concerns. If you are in emotional distress or thinking about harming yourself, contact the 988 Suicide & Crisis Lifeline (call or text 988, US, 24/7) or see the WHO mental-health resources.
Pregnancy Weight Gain Guide
How much weight to gain in pregnancy depends on your pre-pregnancy BMI. The IOM 2009 guidelines define total ranges and weekly pace for each BMI category. This tool tells you your band and whether you are roughly on pace.
The IOM 2009 ranges
Underweight (BMI under 18.5): 28-40 lb total. Normal (18.5-24.9): 25-35 lb. Overweight (25-29.9): 15-25 lb. Obese (30+): 11-20 lb. Weekly pace in the 2nd/3rd trimester: 1.0-1.3, 0.8-1.0, 0.5-0.7, 0.4-0.6 lb/week respectively.
Why this matters
Gaining too little or too much is associated with different maternal and infant outcomes. Tracking against the evidence-based range helps you and your provider stay on a healthy trajectory.
Frequently Asked Questions
Is this medical advice?
No - this is educational reference information. Always follow your obstetric provider's individual recommendations, which may differ for twins, complications, or your history.
What if I am gaining faster or slower than the range?
Single-week fluctuations are normal. If you are consistently off pace, discuss it with your provider.
This tool provides educational health metric estimations only. It is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare provider for medical concerns.