Table 2.

Association between fertility indicator use and fecundability

	Baseline assessment of fertility indicator use						Time varying assessment of fertility indicator use
	No. of pregnancies	No. of cycles	Unadjusted		Adjusteda		No. of pregnancies	No. of cycles	Unadjusted		Adjusteda
			FR	95% CI	FR	95% CI			FR	95% CI	FR	95% CI
No fertility indicator use	782	6,305	1.00	Ref	1.00	Ref	669	5,464	1.00	Ref	1.00	Ref
Any fertility indicator use *	2,551	16,307	1.34	1.24–1.45	1.25	1.16–1.35	2,664	17,148	1.41	1.30–1.53	1.31	1.21–1.42
BBT	737	4,640	1.34	1.22–1.47	1.22	1.11–1.35	833	5,466	1.41	1.28–1.55	1.28	1.16–1.42
Cervical fluid	1,391	8,543	1.40	1.28–1.52	1.29	1.18–1.40	1,506	9,467	1.47	1.35–1.60	1.35	1.23–1.47
Cervix position	429	2,386	1.49	1.33–1.67	1.32	1.17–1.49	458	2,690	1.53	1.36–1.71	1.36	1.21–1.53
Urine LH	1,062	6,961	1.33	1.21–1.45	1.21	1.11–1.33	1,244	8,155	1.44	1.31–1.58	1.31	1.20–1.44
Charting cycles or counting days	2,444	15,372	1.37	1.27–1.48	1.27	1.17–1.37	2,561	16,161	1.44	1.33–1.56	1.33	1.23–1.45

^a= Adjusted for female age, race/ethnicity, gravidity, BMI, income, current smoker, education, partner education, most recent method of birth control hormonal, hours of sleep per night, irregular cycles, history of infertility, prenatal supplement intake, marital status, intercourse frequency, history of benign gynecologic disorder, history of sexually transmitted infection, maternal problems getting pregnant

^*Fertility indicators are not mutually exclusive. Women could contribute cycles to one or more methods.

Abbreviations: BBT: Basal body temperature; Urine LH: Urine LH ovulation testing kit or stick