Table 4.

Neonatal birth characteristics for the three study groups^a

	Mothers ≤ 39 n = 71,472		Mothers 40–45 n = 35,429		Mothers ≥ 45 n = 2229		CHI-SQUARE/ANOVA
	mean/SD		mean/SD		mean/SD		p-value1	p-value2	p-value3	p-value4
Child’s length, cm (mean/SD)	50.34/ 2.65		50.27/ 2.85		49.85/ 3.30		< 0.001b	< 0.001b	< 0.001b	< 0.001b
Child’s weight, gram (mean/SD)	3541.49/ 604.21		3507.06/ 639.68		3403.80/ 706.41		< 0.001b	< 0.001b	< 0.001b	< 0.001b
	n	%	n	%	n	%	p-value1	p-value2	p-value3	p-value4
Twin							< 0.001	0.007	< 0.001	< 0.001
No	68,452	95.8	34,056	96.1	2033	91.2
Yes	3020	4.2	1373	3.9	196	8.8
Gestational age							< 0.001	< 0.001	< 0.001	< 0.001
Very preterm, < 32 weeks	680	1.0	436	1.2	54	2.4
Preterm, 32–36 weeks	3870	5.4	2156	6.1	187	8.4
Post term, > 42 weeks	245	0.3	127	0.4	8	0.4
Birthweight							< 0.001	< 0.001	< 0.001	< 0.001
Low birthweight, 1500 g-2499 g	2633	3.7	1558	4.4	153	6.9
Very low birthweight, < 1500 g	534	0.7	405	1.1	48	2.2
Size for gestational age							< 0.001	< 0.001	< 0.001	0.884
AGA5	67,107	93.9	32,710	92.3	2052	92.1
SGA6	1281	1.8	987	2.8	63	2.8
LGA7	3084	4.3	1732	4.9	114	5.1
Apgar 5							< 0.001	< 0.001	< 0.001	0.168
Low score, 0–6	763	1.1	546	1.6	43	1.9
Apgar 10							< 0.001	< 0.001	< 0.001	0.015
Low score0–6	253	0.4	181	0.5	20	0.9
Child healthc							< 0.001	< 0.001	< 0.001	< 0.001
Healthy – No	14,282	20.4	8422	24.3	602	27.7
Survival							< 0.001	< 0.001	0.011	0.328
0–27 days	123	0.2	102	0.3	9	0.4

^aStudent’s t-test

^bNumbers may not add up to the total due to partially missing data

^cDefined as: Healthy child, examined at the delivery ward

¹Across all age groups

²≤39 vs. 40–44, Pearson’s chi-square

³≤39 vs. ≥45, Pearson’s chi-square

⁴40–44 vs. ≥45, Pearson’s chi-square

⁵Appropriate for gestational age

⁶Small for gestational age

⁷Large for gestational age