Time to Pregnancy (TTP)

By RRM Academy Reviewed by Dr. Naomi Whittaker, MD, Board-Certified OBGYN, MIGS, NFPMC, FCI Updated July 26, 2026

Time to pregnancy (TTP) is the number of months from the start of unprotected intercourse attempting conception to the achievement of a confirmed pregnancy, and it is the primary population-level measure of couple fecundability. A German prospective cohort of couples using fertility-aware, timed intercourse found that 81% conceived within 6 cycles and 92% within 12 cycles; among the couples in that cohort who ultimately proved fertile, the rates were higher still, 88% by 6 cycles and 98% by 12.¹ These probabilities decline with advancing age. When a couple has not conceived after 12 months of appropriately timed attempts, or 6 months at age 35 or older, infertility evaluation is indicated.²

TTP depends substantially on whether intercourse is timed to the fertile window. Couples who cannot identify the peak day of their cycle, or who are not using fertility-focused intercourse, may show extended TTP for behavioral rather than pathological reasons. Accurate TTP reporting requires that couples know when they began attempting and whether attempts were cycle-timed. Extended TTP in the absence of cycle tracking may reflect missed fertile windows rather than underlying disease.

In restorative reproductive medicine, TTP is most meaningfully interpreted as a cumulative outcome over a defined treatment horizon rather than a per-cycle metric. Published NaProTechnology cohort data report outcomes at 24 and 36-plus months, reflecting the time required for diagnosis, treatment of underlying conditions, and physiological restoration.³ This differs from procedural approaches that report per-transfer or per-cycle success rates, a framing that does not capture couples who discontinued treatment. TTP over a full treatment horizon is the relevant comparison metric for couples evaluating care pathways at mature reproductive age.

This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.