Figure 1 Socio-economic comparison of nulliparous teenage and 20-29 year old mothers

SES decile

< 20 years

20-29 years

30-39 years

>40 years

Total

1

1,321
(16.3%)

8,479
(11.4%)

6,328
(9.3%)

378
(9.1%)

16,506
(10.6%)

2

1,037
(12.8%)

9,097
(12.2%)

6,848
(10.0%)

393
(9.5%)

17,375
(11.2%)

3

995
(12.3%)

9,097
(12.2%)

7,025
(10.3%)

389
(9.4%)

17,506
(11.3%)

4

872
(10.8%)

8,390
11.3(%)

6,996
(10.3%)

365
(8.8%)

16,623
(10.7%)

5

795
(9.8%)

7,486
(10.0%)

7,060
(10.3%)

391
(9.4%)

16,146
(10.4%)

6

781
(9.7%)

7,486
(10.0%)

7,128
(10.4%)

449
(10.9%)

15,844
(10.2%)

7

667
(8.3%)

6,996
(9.4%)

7,086
(10.4%)

431
(10.4%)

15,180
(9.8%)

8

604
(7.5%)

6,695
(9.0%)

6,697
(9.9%)

411
(9.9%)

14,677
(9.5%)

9

596
(7.4%)

5,907
(7.9%)

6,738
(9.9%)

452
(10.9%)

13,693
(8.8%)

10

420
(5.2%)

4,556
(6.1%)

6,084
(8.9%)

481
(11.6%)

11,541
(7.4%)

Total

8,088
(100%)

74,603
(100%)

68,260
(100%)

4,140
(100%)

155,091
(100%)

Table1 Maternal age at the birth of the first child by SES

SES

30-39 years

<20 years

20-29 years

>40 years

1

....

1.91(1.73, 2.09)***

1.28(1.22, 1.34)***

0.95(0.82, 1.09)

2

....

1.38(1.25, 1.52)***

1.26(1.21, 1.32)***

0.91(0.79, 1.05)

3

....

1.29(1.17, 1.43)***

1.23(1.18, 1.29)***

0.88(0.76, 1.01)

4

....

1.14(1.03, 1.26)

1.14(1.09, 1.19)***

0.83(0.72, 0.95)

5

....

1.03(0.93, 1.14)

1.07(1.02, 1.12)

0.88(0.76, 1.01)

6

Comparator group

7

....

0.86(0.77, 0.96)

0.94(0.90, 0.98)**

0.97(0.84, 1.11)

8

....

0.79(0.71, 0.88)***

0.92(0.87, 0.96)***

0.94(0.82, 1.07)

9

....

0.81(0.72, 0.90)***

0.83(0.80, 0.88)***

1.06(0.93, 1.22)

10

....

0.63(0.56, 0.71)***

0.71(0.68, 0.75)***

1.26(1.10, 1.43)**

Table2 Odds ratios of maternal age by SES

SES, socio-economic status; **, P-value<0.005; ***, P-value<0.0005

<

SES

20-29 years

<20 years

1

....

1.49(1.36, 1.64)***

2

....

1.09(0.99, 1.20)

3

....

1.05(0.95, 1.16)

4

....

1.00(0.90, 1.10)

5

....

0.96(0.87, 1.07)

6

Comparator group

7

....

0.91(0.82, 1.02)

8

....

0.86(0.77, 0.97)

9

....

0.97(0.86, 1.08)

10

....

0.88(0.78, 1.00)

Table3 A comparison of teenage mothers to 20-29 year old mothers

SES, socio-economic status; ***, P-value<0.0005.