Track recommended weight gain by trimester based on IOM guidelines.
Underweight (BMI < 18.5): gain 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. First trimester: ~0.5–2 kg total. Second/third trimester: steady weekly gain. Excessive weight gain increases risk of gestational diabetes, preeclampsia, and cesarean delivery.