Table 1.

Characteristics of 57,884 women who delivered at term (39 + 0–41 + 6 gestational weeks) or post-term (42 + 0–44 + 6 gestational weeks)

	At term		Post-term
	n	%	N	%
Total	51,268	100.0	6616	100.0
Maternal age
10–25	8846	17.3	1159	17.5
26–30	22,360	43.6	2862	43.3
31–35	15,696	30.6	2004	30.3
36–50	4366	8.5	591	8.9
				P = 0.616
Parity
0	24,596	48.0	3670	55.5
1	18,469	36.0	1971	29.8
2	6720	13.1	796	12.0
3	1217	2.4	146	2.2
4+	238	0.5	29	0.4
Missing	28	0.1	4	0.1
				P = 0.000
Pre-pregnancy BMI
< 18.5	2294	4.5	219	3.3
18.5 - < 25	35,359	69.0	4201	63.5
25 - < 30	9329	18.2	1442	21.8
> 30	3474	6.8	627	9.5
Missing	812	1.6	127	1.9
				P = 0.000
Child’s sex
Male	25,788	50.3	3484	52.7
Female	25,479	49.7	3132	47.3
Missing	1	0.0	0	0.0
				P = 0.001
Socio-occupational status
High	27,109	52.9	3511	53.1
Medium	19,206	37.5	2478	37.5
Low	4764	9.3	606	9.2
Missing	189	0.4	21	0.3
				P = 0.902
Smoking
Yes	7423	14.5	927	14.0
No, but partner smoking	7547	14.7	1057	16.0
No	24,839	48.4	3165	47.8
Missing	11,459	22.4	1467	22.2
				P = 0.054
	39 + 0–41 + 6		42 + 0–44 + 6
	n	%	N	%
Maternal epilepsy, medicated
Yes	113	0.2	11	0.2
No	39,723	77.5	5140	77.7
Missing	11,432	22.3	1465	22.1
				P = 0.638
Psychiatric disorder
Yes	3869	7.5	467	7.1
No	47,357	92.4	6144	92.9
Missing	42	0.1	5	0.1
				P = 0.364
Alcohol consumption during pregnancy
Yes	9351	18.2	1199	18.1
No	30,393	59.3	3939	59.5
Missing	11,524	22.5	1478	22.3
				P = 0.924
Fever during pregnancy
Yes	11,138	21.7	1390	21.0
No	36,898	72.0	4848	73.3
Missing	3232	6.3	378	5.7
				P = 0.049
Folic acid consumption during pregnancy
Yes	12,070	23.5	1567	23.7
No	36,223	70.7	4707	71.1
Missing	175	0.3	12	0.2
				P = 0.062