What is the recommended weight gain during pregnancy for a woman with a normal pre-pregnancy BMI (18.5-24.9)?

Recommended pregnancy weight gain depends on pre-pregnancy BMI (Institute of Medicine guidelines): (1) Underweight (BMI <18.5): 28-40 pounds; (2) Normal weight (BMI 18.5-24.9): 25-35 pounds; (3) Overweight (BMI 25-29.9): 15-25 pounds; (4) Obese (BMI ≥30): 11-20 pounds. Twin pregnancies: higher recommendations (37-54 pounds for normal BMI). Weight gain distribution: ~1-5 pounds in first trimester; ~1 pound per week in second and third trimesters. Weight gain components: baby (~7-8 lbs), placenta (~1-2 lbs), amniotic fluid (~2 lbs), uterus (~2 lbs), breast tissue (~1-3 lbs), blood volume (~3-4 lbs), fat stores (~5-9 lbs), increased fluid (~2-3 lbs). Excessive gain risks: gestational diabetes, preeclampsia, macrosomia, cesarean delivery, postpartum weight retention. Inadequate gain risks: preterm birth, low birth weight, failure to thrive. Nutrition counseling: ~340 additional calories/day in second trimester, ~450 in third; balanced diet emphasizing protein, calcium, iron, folate; prenatal vitamins; avoiding alcohol, smoking, recreational drugs, certain fish (high mercury), unpasteurized products. Track weight at each prenatal visit; address concerning patterns promptly.