Transferring one embryo at a time instead of two significantly improved the live-birth rate from assisted reproduction procedures and reduced costs, according to a report.
The success of elective single embryo transfer (eSET) in the study contrasts with findings from some earlier studies that reported lower birth rates using eSET. The difference can be explained in part by the eSET protocol at the Finnish clinic, which used frozen-thawed embryos if needed after the initial fresh embryo transfer, Dr. Zdravka Veleva of the University of Oulu (Finland) and associates reported.
Between 1995 and 2004, 1,510 women under age 40 underwent in vitro fertilization and/or intra-cytoplasmic sperm injection at Oulu University Hospital. Investigators compared clinical outcomes in two periods—1995–1999, when double embryo transfer (DET) was the norm and only 4% of women had eSET, and 2000–2004, when 46% of 684 women underwent eSET.
The findings—all of which were statistically significant between periods—included:
▸ The cumulative pregnancy rate per egg retrieval increased from 33% in the DET period to 38% in the eSET period.
▸ The cumulative term live birth rate per egg retrieval increased from 23% in the DET period to 28% in the eSET period.
▸ The cumulative term live birth rate per woman increased from 37% in the DET period to 42% in the eSET period.
▸ At the same time, the cumulative multiple birth rate declined from 20% in the DET period to 9% in the eSET period.
A higher proportion (49%) of deliveries in the eSET period occurred after frozen-thawed embryo transfer, compared with the DET period (35%), emphasizing the value of cryopreservation of embryos, “which until now has been underestimated in most countries,” they said.
In the current study, fresh embryos were transferred 2 or 3 days after oocyte collection, but previous data suggest that similar results could be expected if the embryos are transferred up to 5 days after oocyte collection, the researchers said.
Earlier studies included highly selected patient populations, while the current study included all consecutive patients at the clinic in the study period, providing more of a real-life setting that adds validity to the results (Hum. Reprod. doi:10.1093/humrep/).
Using eSET decreased the total treatment cost per woman by 5% compared with the DET period, according to an economic analysis in the current study. A term live birth in the eSET period cost 19,889 less than in the DET period. Dr. Veleva and associates suggested that infertility clinics focus their protocols for women under age 40 on single instead of double (or greater) embryo transfers. Insurers should consider not just the direct costs of treatment but also the costs associated with multiple births. Limiting the number of embryo transfer cycles eligible for reimbursement may result in greater use of multiple-embryo transfers, higher rates of multiple births, and higher total costs. The financial savings from switching to eSET instead of DET potentially could fund many more treatment cycles, they suggested.
The study was funded by the University of Oulu and the Sigrij Jusélius Foundation.