Table 1.

Distributions of selected participant characteristics, according to small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) births, among women (n 8758) and their children enrolled in the 2010–2012 Gansu Provincial Maternity and Child Care Hospital birth cohort, Lanzhou, China

Characteristic	AGA (n 7974)		SGA (n 784)		P value
	n	%	n	%
Maternal age (years)
<25	1812	88·78	229	11·22	<0·001
25–29	3330	92·35	276	7·65
≥30	2832	91·03	279	8·97
Monthly income per capita (RMB)
<3000	4193	89·48	493	10·52	<0·001
≥3000	3781	92·85	291	7·15
Maternal education level
<College	4903	89·67	565	10·33	<0·001
≥College	3071	93·34	219	6·66
Smoking (passive and active)
No	6430	91·65	586	8·35	<0·001
Yes	1544	88·63	198	11·37
Drink during pregnancy
No	7959	91·05	782	8·95	0·684*
Yes	15	88·24	2	11·76
Maternal employment
No	3812	89·69	438	10·31	<0·001
Yes	4162	92·32	346	7·68
Pre-pregnancy BMI (kg/m2)
<18·5	1724	89·70	198	10·30	0·005
18·5–23·9	5292	91·76	475	8·24
≥24·0	958	89·62	111	10·38
Weight gain during pregnancy (kg)
<15	2524	88·34	333	11·66	<0·001
15–18·5	2560	91·72	231	8·28
>18·5	2890	92·93	220	7·07
Pre-eclampsia
No	7768	91·87	687	8·13	<0·001
Yes	206	67·99	97	32·01
Gestational diabetes
No	7913	91·02	781	8·98	0·230
Yes	61	95·31	3	4·69
Parity
Primipara	5826	91·59	535	8·41	0·027
Multipara	2148	89·61	249	10·39
Caesarean section
No	5164	92·30	431	7·70	<0·001
Yes	2810	88·84	353	11·16
History of preterm birth
No	7920	91·12	772	8·88	0·008
Yes	54	81·82	12	18·18
Height of child’s father (cm)
≤175	5416	90·43	573	9·57	0·003
>175	2558	92·38	211	7·62
Gender of live birth
Male	4186	91·52	388	8·48	0·108
Female	3788	90·54	396	9·46

^*Fisher’s exact test.