TABLE 5.

Association Between Chlamydia Status and Getting Pregnant Among Women With a Pregnancy Intention Stratified by Age at Time of Attempting to Conceive

	Planned Pregnancies	Time	Crude HR			aHR
	n*	Person-Months†	HR	95% CI	P	aHR	95% CI	P
1. Age 16–29 y
Chlamydia negative	709	3871	1			1
Chlamydia positive	162	1374	0.78	0.66–0.92	<0.01	0.79	0.67–0.94	<0.01
No infection	709	3871	1			1
1 infection	132	1069	0.80	0.67–0.97	0.01	0.81	0.68–0.97	0.02
Multiple infections	30	305	0.71	0.49–1.03	0.07	0.71	0.49–1.03	0.07
2. Age 30–32 y
Chlamydia negative	425	2162	1			1
Chlamydia positive	98	692	0.72	0.59–0.89	<0.01	0.74	0.60–0.92	<0.01
No infection	425	2162	1			1
1 infection	79	571	0.72	0.58–0.90	<0.01	0.75	0.59–0.94	0.01
Multiple infections	19	121	0.71	0.45–1.13	0.15	0.72	0.45–1.14	0.16
3. Age 33–39 y
Chlamydia negative	485	3649	1			1
Chlamydia positive	131	842	1.07	0.89–1.28	0.48	1.07	0.89–1.28	0.49
No infection	485	3649	1			1
1 infection	115	690	1.11	0.92–1.34	0.29	1.10	0.90–1.33	0.35
Multiple infections	16	152	0.81	0.49–1.34	0.42	0.85	0.50–1.42	0.52

Chlamydia positive was defined as a positive NAAT test outcome in the CSI study (CSI-NAAT), and/or the presence of chlamydia IgG and/or a self-reported chlamydia infection. For these analyses, multiple imputations were used to estimate time of first chlamydia infection in women without a known first year of chlamydia infection. Analyses were stratified for age categories based on tertiles. All models were adjusted for age at pregnancy/trying to get pregnant and migration background.

*Complete cases.

^†Person-months of complete cases.

aHR indicates adjusted hazard ratio; CI, confidence interval; HR, hazard ratio.