Table 1.

Characteristics by gestational age (n=1444)

	Total	Early-term children		Full-term children	P values
		37 weeks† n (%)	38 weeks† n (%)	39–41 weeks† n (%)
Children’s characteristics‡
Weight for length Z-score
Normal	1156 (80.1)	72 (82.8)	162 (79.0)	922 (80.0)	0.765
Over-weighted	288 (19.9)	15 (17.2)	43 (21.0)	230 (20.0)
Gender
Male	722 (50.0)	51 (58.6)	110 (53.7)	561 (48.7)	0.107
Female	722 (50.0)	36 (41.4)	95 (46.3)	591 (51.3)
Maternal characteristics
Parity, n(%)‡
Nulliparous	1255 (8.9)	65 (74.7)	181 (88.3)	1009 (87.6)	0.002*
Multiparous	189 (13.1)	22 (25.3)	24 (11.7)	143 (12.4)
Maternal age at delivery (years)
≥35	49 (3.4)	3 (3.4)	6 (2.9)	40 (3.5)	0.924
<35	1395 (9.6)	84 (96.6)	199 (97.1)	1112 (96.5)
Delivery mode, n (%)
Caesarean section	632 (43.7)	43 (49.4)	101 (49.3)	664 (57.6)	0.101
Vaginal birth	812 (56.2)	44 (50.6)	104 (50.7)	488 (42.4)
Socioeconomic status
City
Wuxi	480 (33.2)	25 (28.7)	92 (44.9)	363 (31.5)	<0.001**
Taiyuan	484 (33.5)	2 (2.3)	16 (7.8)	466 (40.5)
Bingzhou	480 (33.3)	60 (69.0)	97 (47.3)	323 (28.0)
Mother’s higher education
Yes	827 (57.3)	53 (60.9)	143 (69.8)	631 (54.8)	<0.001**
No	617 (42.7)	34 (39.1)	62 (30.2)	521 (45.2)
Father’s higher education
Yes	880 (60.9)	45 (51.7)	151 (73.7)	684 (59.4)	<0.001**
No	564 (39.1)	42 (48.3)	54 (26.3)	468 (40.6)
Mother’s occupation
Skilled	824 (57.1)	45 (51.7)	124 (60.5)	655 (56.9)	0.365
Non-skilled	620 (42.9)	42 (48.3)	81 (39.5)	497 (43.1)
Father’s occupation
Skilled	869 (60.2)	46 (52.9)	129 (62.9)	694 (60.2)	0.275
Non-skilled	575 (39.8)	41 (47.1)	76 (37.1)	458 (39.8)

*p<0.01; **p<0.001.

†Gestational week.

‡Χ² analysis.