Table 5.

ORs of SGA pairs in relation to GWG and pre-pregnancy BMI.

Pre-pregnancy BMI (kg/m2)		NO. of SGA pairs/NO. of AGA pairs	Crude OR (95% CI)	P value	Adjusted OR (95% CI)	P value
Total GWG
Low	IOM	65/1279	2.39 (1.56, 3.67)	<0.0001	2.53 (1.64, 3.91)	<0.0001*
	Chinese	58/1618	2.67 (1.86, 3.83)	<0.0001	2.92 (2.02, 4.21)	<0.0001*
Normal	IOM	58/3049	Reference		Reference
	Chinese	34/2270
High	IOM	25/1395	0.95(0.53, 1.71)	0.8699	0.90 (0.50, 1.62)	0.7215*
	Chinese	17/1192	0.94 (0.59, 1.51)	0.8049	0.88 (0.55, 1.42)	0.6038*
Underweight (<18.5 kg/m2)
Low GWG	IOM	—	—	—	—	—
	Chinese	16/118	3.45 (1.63, 7.23)	0.0012	4.96 (2.25, 10.93)	<0.0001§
Normal GWG	IOM	—	—	—	—	—
	Chinese	14/356	Reference
High GWG	IOM	—	—	—	—	—
	Chinese	9/169	1.35 (0.58, 3.19)	0.4881	1.37 (0.57, 3.30	0.4839
Normal (18.5~23.9 kg/m 2 )
Low GWG	IOM	50/1387	2.14 (1.36, 3.35)	0.0009	2.30 (1.46, 3.63)	0.0004§
	Chinese	42/937	2.63 (1.70, 4.08)	<0.0001	2.80 (1.79, 4.38)	<0.0001§
Normal GWG	IOM	32/1897	Reference		Reference
	Chinese	40/2347
High GWG	IOM	14/1054	0.79 (0.42, 1.48)	0.459	0.75 (0.40, 1.42)	0.3835§
	Chinese	14/1054	0.78 (0.42, 1.44)	0.4254	0.74 (0.40, 1.36)	0.3286§
Overweight and obese (> = 24 kg/m2)
Low GWG	IOM	2/231	6.46 (1.36, 30.68)	0.0190	5.59 (1.22, 28.25)	00276§
	Chinese	7/224	2.70 (0.79, 9.34)	0.1159	2.45 (0.70, 8.62)	0.1615§
Normal GWG	IOM	2/373	Reference		Reference
	Chinese	4/346
High GWG	IOM	3/138	4.06 (0.67, 24.52)	0.1274	3.43 (0.56, 21.02)	0.1830§
	Chinese	2/172	1.01 (0.18, 0.55)	0.9947	0.94 (0.17, 5.25)	0.9455§

Abbreviations: OR, odds ratio; CI: confidence interval; SGA, small for gestational age; AGA, appropriate for gestational age.

^*Adjusted for maternal delivery age (continuous), education level, parity, gravidity, pre-pregnancy BMI, sex of twin infants, and gestational weeks.

^§Adjusted for maternal delivery age (continuous), education level, parity, gravidity, sex of twin infants, and gestational weeks.