Day 5 versus day 3 embryo transfer: a controlled randomized trial.
Blastocyst transfer has been suggested to improve implantation rate without affecting pregnancy rate. The aim of this study was to compare the pregnancy and implantation rates of day 3 and 5 transfers in a prospective randomized manner. Patients with four or more zygotes were randomly allocated on day 1 to either day 3 or 5 transfers. Fertilization was achieved through regular IVF or intracytoplasmic sperm injection. Zygotes were kept in Medicult IVF medium for day 3 transfers and transferred into G1.2 and G2.2 on day 1 and 3 respectively for day 5 transfers. The morphologically best two or three embryos or blastocysts were chosen for transfer in both groups. Overall pregnancy rates per embryo transfer were the same (39%) in day 3 and 5 transfers. Implantation rates were 21 and 24% for day 3 and 5 transfers respectively. The pregnancy and implantation rates for day 5 transfers were significantly affected by the availability of at least one blastocyst to transfer and the number of zygotes. The number of good quality embryos on day 3 also significantly affected pregnancy and implantation rates on day 5 transfers. Multiple gestation rate, number of abortions and ongoing pregnancies were similar in both groups. In conclusion, day 3 and 5 transfer had similar pregnancy, implantation and twinning rates. Currently, day 5 transfers have no advantages over day 3 transfers.
Coskun
S
S
Departments of Pathology and Laboratory Medicine and Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Center, P.O. Box 3354, Riyadh, Saudi Arabia.
Hollanders
J
J
Al-Hassan
S
S
Al-Sufyan
H
H
Al-Mayman
H
H
Jaroudi
K
K
D000328:Adult; D001755:Blastocyst / Q000502:physiology*; D046508:Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods*; D004622:Embryo, Mammalian / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors