Successful pregnancy rates achieved with day 4 embryo transfers.

Objective: To assess the success of day 4 embryo transfers (ETs) following IVF at one institution.

Design: Retrospective analysis.

Setting: A university hospital IVF program.

Patient(s): Two hundred nondonor, fresh IVF cycles.

Intervention(s): None.

Main Outcome Measure: Outcomes of IVF. Outcome assessments after day 4 ETs included rates of implantation, clinical pregnancy, and singleton and multiple live births.

Result(s): The overall live-birth rate was 54.4%. Implantation rates were highest in younger age groups, and similar in patients 35-40 years of age. Pregnancy and live-birth rates were similar across all age groups up to age 40 years. Multiple gestations were highest in women < or =40 years of age.

Conclusion: Acceptable pregnancy rates can be achieved with day 4 ETs.