Table 3. Predictors of pregnancy among HIV-positive women already accessing HIV clinical care at UK CHIC sites in 2000-2009.

Variables		Person- years	Pregnancies	Pregnancy rate (per 100 person-years)	95% CI	Relative Rate	95% CI	p	Adjusted Relative Rate*	95% CI	p
Year of conception**		38,097	1637	4.3	4.1 - 4.5	1.03	1.01-1.05	<0.001	1.05	1.03-1.07	<0.001
Age group	16-25 years	3486	254	7.3	6.4 - 8.1	1.12	0.98-1.29	0.10	1.12	0.98-1.29	0.11
	26-35 years	15,927	1032	6.5	6.1 - 6.9	1.00	-	-	1.00	-	-
	36-49 years	18,684	351	1.9	1.7 -2.1	0.30	0.26-0.34	<0.001	0.29	0.25-0.33	<0.001
ART use CD4 count (cells/mm3)	On ART	22,512	890	4.0	3.7 - 4.2	0.82	0.74-0.91	<0.001	0.95	0.85-1.05	0.32
	≤200	6073	183	3.0	2.6 - 3.4	0.64	0.54-0.76	<0.001	0.65	0.55-0.77	<0.001
	201-350	8841	421	4.8	4.3 - 5.2	1.00	-	-	1.00	-	-
	>350	21,155	981	4.6	4.4 - 4.9	0.98	0.87-1.10	0.71	0.99	0.88-1.11	0.83
	NK	2028	52	2.6	1.9 -3.3	0.54	0.41-0.72	<0.001	0.52	0.39-0.68	<0.001
Ethnicity	White	6993	203	2.9	2.5 - 3.3	0.62	0.52-0.73	<0.001	0.67	0.57-0.80	<0.001
	Black-Caribbean	1483	59	4.0	3.0 - 5.0	0.85	0.65-1.11	0.23	0.75	0.58-0.97	0.03
	Black-African	24,837	1173	4.7	4.5 - 5.0	1.00	-	-	1.00	-	-
	Black-other	1004	49	4.9	3.5 - 6.2	1.04	0.77-1.39	0.81	0.94	0.71-1.25	0.68
	Other	2069	75	3.6	2.8 - 4.4	0.77	0.59-0.99	0.04	0.71	0.56-0.91	0.01
	Not reported	1711	78	4.6	3.6 - 5.5	0.96	0.75-1.23	0.76	0.95	0.75-1.20	0.66

^*Where all variables in the table were included in the model.

^**As year is a continuous variable, RRs refer to an increase of one year.