Korean J Fertil Steril.  2000 Jun;27(2):165-172.

Subsequent Embryo Transfers (SET) on Day 2 and 5: It's Safety and Effectiveness

• Lee TH
• Chun SS
• Park KS
• Song HB

Abstract

OBJECTIVE
In vitro fertilization (IVF) and a prolonging the time of culture may be helpful in establishing a viable pregnancy through a selection effect. Some embryos do not develop beyond the 4-cell stage and some may not develop to the blastocyst stage. We have evaluated the safety of SET and the outcomes of pregnancy.
METHODS
Sperms were treated with Ham's F-10 supplemented with 10% human follicular fluid (hFF). Oocytes or fertilized oocytes were cultured in Dulbecco's Modified Eagle Medium (DMEM) with 10% or 20% hFF respectively. Up to five oocytes were inseminated with approximately 200,000 sperm cells/2 ml in each well. Fertilization was examined in the following morning and fertilized oocytes were co-cultured until embryo transfer. Vero cells for co-culture were prepared in Tissue Culture Medium - 199 (TCM-199) with 10% fetal bovine serum. At the two to four cell and blastocyst on day 2 and day 5, embryo and blastocyst grading were evaluated. Pregnancy rate was determined after transfer of human embryos at the two to four cell stage on day 2 (Group I) or subsequent transfer of embryos on day 2 and at the blastocyst stage on day 5 (Group II). For statistically significant when rho value was less than 0.05.
RESULTS
No differences was found in the fertilization between Group I(81.0%, 98/121) and Group II(81.8%, 180/220). In case of cleavage rate, no difference was found in Group I(95.9%, 94/98) and Group II(66.7%, 12/18) than in Group (26.3%, 5/19).
CONCLUSION
The results of this study showed that SET is safe and effective, and significantly increases the pregnancy rate.

MeSH Terms

Blastocyst
Coculture Techniques
Eagles
Embryo Transfer*
Embryonic Structures*
Female
Fertilization
Fertilization in Vitro
Follicular Fluid
Humans
Oocytes
Pregnancy
Pregnancy Rate
Spermatozoa
Vero Cells