Time to Pregnancy (TTP)

Time to pregnancy (TTP) is the number of months from the time a couple begins trying to conceive until pregnancy is confirmed. The count includes only months in which the couple uses no contraception. TTP is the main measure researchers use to compare how quickly groups of couples conceive. A German study followed couples who tracked their fertile days. 81% conceived within 6 cycles. 92% conceived within 12 cycles. Among the couples in that study who later proved fertile, the rates were higher still, 88% by 6 cycles and 98% by 12.¹ These chances decline as a woman ages. Major professional societies advise an infertility evaluation after 12 months of regular, unprotected intercourse. At age 35 or older, the interval is 6 months.²

TTP depends heavily on whether a couple has intercourse during the fertile window. Some couples cannot identify the peak day of the cycle, or do not use fertility-focused intercourse. These couples may take longer to conceive for behavioral reasons rather than medical ones. Useful TTP data require two facts. Clinicians need to know when the couple began trying and whether intercourse was timed to the fertile window. A long TTP without cycle tracking may reflect missed fertile windows rather than disease.

Restorative reproductive medicine reads TTP as a cumulative total over a defined treatment window rather than as a per-cycle figure. Published NaProTechnology cohort data report results at 24 months and at 36 months or more. That span allows time to identify the cause, treat it, and let the body recover.³ Procedural approaches instead report success per transfer or per cycle. That framing omits couples who stopped treatment. For couples weighing care paths at mature reproductive age, TTP across a full treatment window is the figure that matters.