Clinical outcome of day 2 versus day 5 transfer in cycles with one or two developed embryos.
OBJECTIVE
To determine whether extended culture of embryos to blastocysts has any benefit in cycles with only one or two created embryos.


METHODS
Retrospective analysis of cycles comparing outcomes of day 2 and day 5 transfers. Our day 2 group was from the year 1999 and our day 5 group, from the year 2000.


METHODS
Assisted reproductive technology program of a teaching hospital.


METHODS
All patients, irrespective of age, who had developed one or two embryos.


METHODS
Stimulated IVF, intracytoplasmic sperm injection, or testicular sperm extraction and intracytoplasmic sperm injection cycles with 2-day culture in universal IVF medium (n = 133) or 5-day culture in BlastAssist media (MediCult, Jyllinge, Denmark; n = 132).


METHODS
Pregnancy, implantation, and take-home baby rates.


RESULTS
In the groups of 2-day and 5-day culture, embryo transfer was performed in 98% and in 57% of cycles, respectively. However, the total implantation rate per created embryo (18% vs. 18%), the pregnancy rate per cycle (23% vs. 21%), and the take-home baby rate (69.4% vs. 71.4%) did not differ between the day 2 and day 5 groups.


CONCLUSIONS
Extended culture of embryos does not improve or decrease their capacity for implantation but only allows for better selection and is therefore not necessary in cycles with fewer than three embryos.
Kovacic
Borut
B
Department of Reproductive Medicine and Gynecologic Endocrinology, Maribor Teaching Hospital, Maribor, Slovenia. borut.kov@sb-mb.si
Vlaisavljević
Veljko
V
Reljic
Milan
M
Gavrić Lovrec
Vida
V
D000328:Adult; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors