Pregnancy rate and time to pregnancy after recurrent implantation failure (RIF)-a prospective cohort follow-up study

The goal of this study was to determine ongoing pregnancy rate, time to pregnancy and embryo transfers to pregnancy within a cohort of patients with recurrent implantation failure (RIF).

IVF patients with RIF were included after referral to the RIF outpatient clinic. They received a questionnaire 1 year after inclusion. If data was missing, medical files were examined to determine pregnancy outcomes and conception methods. The ability of the RIF outpatient clinic to improve pregnancy chance or increase the number of patients who elected to continue treatment was beyond the scope of this study.

The cumulative incidence of ongoing pregnancy in IVF patients with RIF (n = 79) after 1 year of follow-up was 40.5% (95% confidence interval = 30.4-51.5%). Median time to pregnancy was 4 months. Pregnancy incidence increased gradually up to 5 embryo transfers (mostly single embryo transfers). The average embryo transfers to pregnancy were 7.3 transfers.

In IVF patients with RIF, up until the 5th embryo transfer, each transfer represents a good opportunity for ongoing pregnancy. This data can be used to counsel patients that regular treatment continuation seems to be well justified even when IVF patients fulfil the RIF criteria.

CCMO: NL66835.068.18. METC 18-040. OMON: NL-OMON24778.