Table 12. Change in the computed number of cycles of attempted conception required for various indicators of subfertility to be attained, as a result of reproductive ageing during the conception process being switched off, for example 5.

	Median intrinsic conception rate <0.05	90th percentile of intrinsic conception rate <0.2	Probability of conceiving in next cycle <0.1	Probability of conceiving in next cycle <0.05	Probability of conceiving in next 12 cycles <0.5
Age 25	+2	0	+1	+2	+1
Age 30	+2	+1	+1	+2	+2
Age 35	+2	+1	0	+2	+2
Age 40	+1	0	0	+2	+1

The model of how fertility declines with age for example 5 is described in the text, with details of the computational implementation given in the supporting information (text S1).