Table 1.

Demographic details of mothers' in the city, suburb and rural areas, Zhejiang Province, People's Republic of China, 2004–2005 (n = 1520)

Variable	City		Suburb		Rural		Total
	n	%	n	%	n	%	n	%
Residence	638	42.0	347	22.8	535	35.2	1520	100.0
Maternal Age (years)*
<25	77	12.0	124	35.7	158	30.6	358	23.9
25–29	383	60.2	165	47.6	255	49.2	800	53.5
30–34	151	23.9	51	14.7	80	15.5	282	18.9
≥35	25	3.9	7	2.0	24	4.7	56	3.7
Missing	5		0		19		24
Maternal education (years)*
≤9	57	9.0	206	59.4	282	53.1	544	36.0
10–12	172	26.9	78	22.5	121	22.9	370	24.5
>12	407	64.1	63	18.2	127	24.0	597	39.5
Missing	3				6		9
Maternal employment*
Labour job	67	10.5	188	55.1	238	47.1	492	33.3
Office job	494	78.4	90	26.4	179	35.4	763	51.7
Not employed	70	11.1	63	18.5	89	17.4	221	15.0
Missing	8		6		30		44
Gestation (weeks)*
<37	30	4.7	7	2.0	12	2.4	49	3.3
≥37	605	95.3	340	98.0	499	97.6	1443	96.7
Missing	3		0		25		28
Birth weight (g)
<2500	9	1.4	7	2.0	11	2.1	27	1.8
2500–3999	583	91.8	310	89.3	489	93.3	1382	91.8
≥4000	43	6.8	30	8.6	24	4.6	97	6.4
Missing	3		0		11		14
Delivery method*
Vaginal	155	24.3	90	25.9	252	47.2	495	32.7
Caesarean	481	75.7	257	74.1	281	52.8	1019	67.3
Missing	3		0		3		6
Birth order*
1	615	96.9	290	84.1	442	83.4	1347	89.2
≥2	20	3.1	55	15.9	89	16.6	163	10.8
Missing	3		2		5		10
Baby's gender
Male	347	54.2	162	47.4	260	49.7	767	51.1
Female	291	45.8	180	52.6	263	50.3	734	48.9
Missing	2		5		12		19
Monthly family income* (RMB)
≤1500	6	1.0	51	15.0	158	31.3	215	14.6
1501–3000	75	11.9	145	42.8	182	35.9	401	27.2
3001–5000	227	35.7	97	28.6	129	25.6	451	30.6
>5000	326	51.5	46	13.6	36	7.1	407	27.6
Missing	7		8		31		46

* p < 0.05