TABLE 2.

Incidence and crude ORs of low birthweight (LBW) and small‐for‐gestational‐age (SGA) according to gestational hypertension, pre‐eclampsia, and other women's characteristics, China, 1993 to 1996

Characteristics	No.	LBW			SGA
		Incidence (%)	OR	95% CI	Incidence (%)	OR	95% CI
Age, year
<20	922	4.66	2.03	1.49, 2.77	8.35	1.36	1.08, 1.73
20–25	115 995	2.35	1	—	6.26	1	—
25–30	60 323	2.24	0.95	0.89, 1.02	5.65	0.90	0.86, 0.94
≥30	24 244	1.74	0.74	0.67, 0.82	4.36	0.68	0.64, 0.73
Body mass index, kg/m2
<18.5	28 695	2.94	1.37	1.27, 1.48	8.10	1.49	1.43, 1.57
18.5–23.9	161 069	2.17	1	—	5.57	1	—
24–27.9	10 765	1.71	0.78	0.68, 0.91	4.37	0.77	0.70, 0.85
≥28	955	1.88	0.87	0.54, 1.38	3.77	0.66	0.48, 0.93
Education
High school or higher	22 145	1.83	1	—	4.75	1	—
Junior high school	119 674	2.19	1.20	1.08, 1.33	5.70	1.21	1.13, 1.30
Primary school or lower	59 665	2.55	1.40	1.26, 1.57	6.60	1.42	1.32, 1.52
Occupation
Farmer	119 047	2.24	1	—	5.86	1	—
Factory worker	55 179	2.41	1.08	1.01, 1.15	6.29	1.08	1.03, 1.12
Other	27 258	2.02	0.90	0.82, 0.99	5.01	0.85	0.80, 0.90
Parity
Multiparous	34 076	1.92	1	—	4.21	1	—
Primiparous	167 408	2.32	1.21	1.12, 1.32	6.20	1.50	1.42, 1.59
Ethnicity
Han	200 010	2.24	1	—	5.85	1	—
Other	1474	3.53	1.59	1.21, 2.10	7.46	1.30	1.07, 1.58
Folic acid use
None	95 925	2.37	1	—	5.80	1	—
Use	105 559	2.14	0.90	0.85, 0.96	5.92	1.02	0.99, 1.06
Anemia during pregnancy
No	33 016	2.19	1	—	5.96	1	—
Yes	129 208	2.16	0.98	0.91, 1.07	5.79	0.97	0.92, 1.02
Gestational Hypertension
No	182 217	2.11	1	—	5.68	1	—
Yes	19 267	3.58	1.72	1.58, 1.87	7.58	1.36	1.29, 1.44
Pre‐eclampsia
No	196 583	2.16	1	—	5.74	1	—
Yes	4901	6.02	2.90	2.57, 3.28	10.67	1.96	1.79, 2.15

Abbreviation: CI, confidence interval; and OR, odds ratio.