Table 2.

Univariable and multivariable analyses of demographic characteristics associated with having a repeat pregnancy, 2000-2009

Characteristic	N(%)*	Univariable analysis		Multivariable analysis (n=7525)
		HR (95% CI)	p-value	aHR (95% CI)	p-value
Year of first reported pregnancy
Change per year	-	1.00 (0.98-1.02)	0.929	1.02 (1.00-1.04)	0.134
Age at first reported pregnancy
<25 years	1860 (35.2)	1		1
25-29 years	2829 (28.8)	0.82 (0.74-0.90)	<0.001	0.86 (0.77-0.97)	0.010
30-34 years	2469 (23.1)	0.68 (0.61-0.76)	<0.001	0.73 (0.64-0.83)	<0.001
35+ years	1460 (13.4)	0.40 (0.34-0.47)	<0.001	0.44 (0.37-0.53)	<0.001
Region of birth
UK and Ireland	1086 (29.0)	1		1
Europe	261 (19.9)	0.69 (0.51-0.92)	0.012	0.73 (0.54-0.98)	0.038
Eastern Africa	3773 (23.7)	0.76 (0.67-0.86)	<0.001	0.83 (0.72-0.95)	0.006
Middle Africa	613 (35.4)	1.18 (0.99-1.40)	0.058	1.29 (1.07-1.55)	0.008
Western Africa	1412 (32.4)	1.13 (0.98-1.31)	0.089	1.16 (1.00-1.36)	0.056
Southern Africa	737 (21.9)	0.68 (0.56-0.82)	<0.001	0.62 (0.51-0.77)	<0.001
Africa (unspecified)	115 (8.7)	0.24 (0.13-0.46)	<0.001	0.24 (0.11-0.51)	<0.001
Elsewhere	491 (26.3)	0.80 (0.65-0.98)	0.035	0.85 (0.69-1.06)	0.147
Parity at first reported pregnancy
Nulliparous	3313 (30.0)	1		1
1	2517 (23.7)	0.75 (0.68-0.83)	<0.001	0.83 (0.75-0.93)	0.001
2	1160 (21.0)	0.65 (0.56-0.75)	<0.001	0.79 (0.68-0.91)	0.002
3+	662 (17.4)	0.50 (0.41-0.60)	<0.001	0.65 (0.53-0.80)	<0.001

HR – Hazard Ratio, aHR – Adjusted Hazard Ratio

^*N is the total of number women, and the proportion of those women who had repeat pregnancies is shown in brackets