Table 2.

Comparison of sporadic anovulation rates of 1%, 8% and 14.5% on simulated time to pregnancy and fecundability odds ratios^a over 12 cycles of follow-up in a cohort of 100,000 women^b (using Scenario 1^c relationship between sex and implantation)

	anovulation = 14.5%			anovulation = 8%				anovulation = 1%
Cycle	Population at risk	% becoming pregnant	Cumulative pregnancy rate (%)	Population at risk	% becoming pregnant	Cumulative pregnancy rate (%)	FORd	Population at risk	% becoming pregnant	Cumulative pregnancy rate (%)	FORd
1	100,000	31.2	31.2	100,000	33.5	33.5	1.11	100,000	36.0	36.0	1.24
2	68,827	26.5	49.4	66,544	28.6	52.5	1.13	64,008	30.6	55.6	1.28
3	50,559	22.3	60.7	47,526	23.9	63.8	1.14	44,399	25.6	67.0	1.31
4	39,301	19.3	68.3	36,190	20.7	71.3	1.15	33,015	22.5	74.4	1.35
5	31,705	16.7	73.6	28,699	17.9	76.4	1.16	25,598	19.1	79.3	1.37
6	26,408	14.1	77.3	23,572	15.2	80.0	1.18	20,698	16.4	82.7	1.40
7	22,690	12.3	80.1	19,982	13.2	82.7	1.18	17,312	14.2	85.1	1.42
8	19,901	10.1	82.1	17,343	10.9	84.6	1.19	14,857	11.7	86.9	1.44
9	17,883	9.1	83.7	15,455	9.7	86.0	1.20	13,126	10.4	88.2	1.46
10	16,261	7.4	85.0	13,963	8.0	87.2	1.20	11,761	8.5	89.2	1.47
11	15,051	6.3	85.9	12,842	6.7	88.0	1.21	10,761	7.2	90.0	1.48
12	14,102	5.7	86.7	11,977	6.3	88.8	1.21	9,985	6.9	90.7	1.49

^aFecundability odds ratios for 1% and 8% anovulation calculated relative to 14.5% anovulation

^bSex in the fertile window set equal to 87% for each cycle of observation; implantation given fertilization = 70% and fertilization given sex and ovulation = 59% for the first cycle of observation, followed by a 7.5% reduction per cycle for implantation given fertilization and fertilization given sex and ovulation; probability of implantation calculated using Equation 1.

^cScenario 1: among fecund couples attempting conception, the maximum probability of attaining pregnancy is ~38% when sexual intercourse always occurs in the fertile window (sex = 1.0)¹⁵.

^dFecundability Odds Ratio