Efficacy of blastocyst transfer after implantation failure.
Clinicians who treat unsuccessful couples despite repeated transfers of good quality embryos face a challenge. Among the various strategies that have been described, embryo transfer at the blastocyst stage has been postulated to improve implantation. A prospective non-randomized analysis was performed in 276 IVF patients who failed to conceive after at least two early embryo transfers of at least two grade 1-2 embryos per cycle. For the next attempt, couples chose between day 2 embryo transfer (D2 group; n = 147) and day 5/6 blastocyst transfer (D5/D6 group; n = 129) before starting the following attempt. Embryo quality was assessed and results were expressed as clinical pregnancy, live birth and implantation rates per cycle. Embryo grade 1 number was similar between both groups, whereas mean embryo score of the whole cohort was slightly higher in the D2 group. The live birth rates per cycle (27.9 versus 19.7%) and implantation rates per cycle (25.4 versus 12.4%) were higher in the D5/D6 group compared with the D2 group. Improved embryo selection and uterine receptivity may explain the additional benefit of embryo transfer at the blastocyst stage for couples with repeated implantation failures.
Guerif
F
F
Médecine et Biologie de la Reproduction, Groupement de Gynécologie-Obstétrique, Medecine Foetale et Reproduction Humaine, CHU Bretonneau, 37044 Tours, France.
Bidault
R
R
Gasnier
O
O
Couet
M L
ML
Gervereau
O
O
Lansac
J
J
Royere
D
D
D000328:Adult; D001723:Birth Rate; D046149:Embryo Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D019233:Retreatment; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors; D017211:Treatment Failure; D016896:Treatment Outcome