Table 3.

The comparison between proposed optimal GWG and IOM recommended GWG grouped by prepregnancy BMI.

	Chinese BMI standard(kg/m2)	Optimal total GWG(kg)	IOM BMI standard(kg/m2)	IOM recommended GWG(kg)	IOM recommended weekly GWG(kg/w)
Underweight	< 18.5	16–21.5	< 18.5	–	–
Normal weight	18.5 ≤ BMI < 24	15–21.1	18.5 ≤ BMI < 25	16.8–24.5	0.45–0.66
Overweight	24 ≤ BMI < 28	13–20	25 ≤ BMI < 30	14.1–22.7	0.38–0.61
Obese	≥ 28	9–22	≥ 30	11.3–19.1	0.31–0.52

BMI body mass index, GWG gestational weight gain, IOM Institute of Medicine.