Body Mass Index and Pregnancy: Establishing a “ Term BMI ”

1. Body Mass Index and Pregnancy: Establishing a “Term BMI” Diana Garretto, MD & Erin Stevens, MD State University of New York at Stony Brook University Medical Center Department of Obstetrics, Gynecology, & Reproductive Medicine Results Tables Objective To use the 2009 recommendations by the Institute of Medicine(IOM) on weight gain during pregnancytocalculate what the appropriate BMI at term would be. A patient would be considered underweight if the BMI at term was <23.5, normal weight if the BMI at term was 23.5-29.9, overweight if the BMI at term was 30-33.5 and obese if the BMI at term was >33.5. Study Design Conclusions The IOM recommends a 28-40 lb weight gain for underweight pregnant patients, a 25-35 lb gain for normal weight, 15-25 lb gain for overweight and a 11-20 gain for obese. In non-pregnant populations, underweight is a BMI <18.5, normal weight is a BMI 18.5-24.9, overweight is a BMI 25-29.9 and obese is a BMI >30. The BMI at term was calculated based on the weight gain recommendations for underweight, normal weight, overweight and obese patients. BMI is calculated using the formula BMI = kg/m2. The BMI calculator at the NIH website was used to perform the calculations. Heights of 5’0’, 5’5’, and 5’10’ were used as representative heights. Individuals at 5’ were assigned the lower limit of the weight gain and 5’10’ the upper limit. A standard BMI at term can be easily calculated and applied to obstetric practice. Using the “Term BMI” at the time of delivery may be an easier way to objectively assess risks of obesity at term than weight alone. FutureResearch Validation of the “term BMI” in regards to mode of delivery, diabetes, estimated blood loss, preeclampsia via a retrospective chart review is currently underway.