Optimizing embryo selection with day 5 transfer.

Area of Science:

• Reproductive Medicine
• Embryology
• In Vitro Fertilization (IVF)

Background:

• Embryo transfer (ET) timing is crucial in IVF.
• Extended embryo culture to day 5 (d5) aims to improve embryo selection.
• Comparison between d5 and day 3 (d3) ET outcomes is essential for optimizing protocols.

Purpose of the Study:

• To compare implantation, pregnancy, miscarriage, multiple gestation, and selective reduction rates.
• To evaluate the efficacy of day 5 embryo transfer versus day 3 embryo transfer in patients aged 42 years.
• To assess the impact of extended embryo culture on IVF success and complication rates.

Main Methods:

• Retrospective cohort study at a university-based IVF center.
• Compared first d5 ET cycles (2003-2006) with historical first d3 ET cycles (1996-1999).
• Included patients aged 42 years who met current d5 ET criteria.

Main Results:

• Day 5 ET showed higher implantation rates (39% vs. 30%).
• Day 5 ET resulted in lower rates of high-order multiple pregnancy (HOMP) and multiple deliveries.
• Fewer selective reductions for HOMP were needed with d5 ET.

Conclusions:

• Extended embryo culture (d5 ET) enhances embryo selection via improved implantation.
• This facilitates fewer embryo transfers, reducing multiple gestation rates.
• D5 ET lowers the incidence of high-order multiple pregnancies and the need for selective reduction.