title: Pregnancy outcome after blastocyst stage transfer comparing to early cleavage stage embryo transfer.
abstract: Blastocyst transfer has been introduced as an alternative for improving the chance for in vitro fertilizations (IVF) implantation. The present study was to evaluate pregnancy rates when embryo transfer was performed either on day 2-3 (cleavage stage) or on day 4-5 (blastocyst stage). This randomized clinical trial included 118 infertile women. All the study subjects underwent controlled ovarian stimulation using a long protocol and randomized into two groups. BS group (n = 57), the culture was extended to day 5 (blastocyst stage) and in the CS-group (n = 61), embryo culture was continued to day 3 (cleavage stage). Ongoing pregnancies, abortion, implantation rate were evaluated. No significant differences were seen in the pregnancy rate between the two groups (33.3% in the BS group versus 27.9% in the CS group; p = 0.519). Abortion, implantation rate in two groups are not significant. Despite the lack of statistical difference between the two study groups, our data suggest that blastocyst transfer may be associated with a higher pregnancy and an overall better implantation rates. However, further studies with larger sample size are mandatory to confirm these findings.
authors.affiliation: a Vali-e-Asr Reproductive Health Research Center, Tehran University of Medical Sciences , Tehran , Iran .
authors.forename: Elham
authors.initials: E
authors.lastname: Aziminekoo
authors.affiliation: b Departments of Obstetrics and Gynecology , Vali-e-Asr Hospital, Tehran University of Medical Sciences , Tehran , Iran , and.
authors.forename: Maryam Sadat
authors.initials: MS
authors.lastname: Mohseni Salehi
authors.affiliation: c The American University of Integrative Sciences, St. Maarten School of Medicine , St. Maarten , USA.
authors.forename: Vahid
authors.initials: V
authors.lastname: Kalantari
authors.affiliation: a Vali-e-Asr Reproductive Health Research Center, Tehran University of Medical Sciences , Tehran , Iran .
authors.forename: Ensieh
authors.initials: E
authors.lastname: Shahrokh Tehraninejad
authors.affiliation: a Vali-e-Asr Reproductive Health Research Center, Tehran University of Medical Sciences , Tehran , Iran .
authors.forename: Fedyeh
authors.initials: F
authors.lastname: Haghollahi
authors.affiliation: a Vali-e-Asr Reproductive Health Research Center, Tehran University of Medical Sciences , Tehran , Iran .
authors.forename: Batool
authors.initials: B
authors.lastname: Hossein Rashidi
authors.affiliation: a Vali-e-Asr Reproductive Health Research Center, Tehran University of Medical Sciences , Tehran , Iran .
authors.forename: Zahra
authors.initials: Z
authors.lastname: Zandieh
mesh_terms: D000022:Abortion, Spontaneous; D000328:Adult; D002970:Cleavage Stage, Ovum / Q000637:transplantation*; D046149:Embryo Culture Techniques / Q000379:methods*; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D010062:Ovulation Induction; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D013997:Time Factors
keywords: Blastocyst stage; early cleavage stage; embryo transfer; in vitro fertilization failure