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Replacement of Fresh Embryo Transfers (ETs) by Frozen Embryo Transfers (FETs) Using Vitrification

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ClinicalTrials.gov Identifier: NCT00823121
Recruitment Status : Unknown
Verified April 2009 by Yazd Research & Clinical Center for Infertility.
Recruitment status was:  Recruiting
First Posted : January 15, 2009
Last Update Posted : January 20, 2010
Information provided by:
Yazd Research & Clinical Center for Infertility

January 14, 2009
January 15, 2009
January 20, 2010
August 2008
February 2009   (Final data collection date for primary outcome measure)
implantation rate [ Time Frame: 4 weeks ]
Same as current
Complete list of historical versions of study NCT00823121 on ClinicalTrials.gov Archive Site
on going pregnancy rate [ Time Frame: 3 months ]
Same as current
Not Provided
Not Provided
Replacement of Fresh Embryo Transfers (ETs) by Frozen Embryo Transfers (FETs) Using Vitrification
Can Fresh Embryo Transfers be Replaced by Cryopreserved-thawed Embryo Transfers in Assisted Reproductive Cycles?
Cryopreservation of all embryos and transferring them subsequently in assisted reproductive technology (ART) cycles to improve outcome.

All patients in the initial cohort were treated with long protocol for ovarian stimulation. For pituitary down-regulation, patients were treated with daily administration of 0.5 mg buserelin (suprefact, Aventis, Frankfurt, Germany) from day 21 of menstrual cycle. Buserelin was reduced to 0.25 mg daily when ovaries were quiescent on ultrasound, and COH was initiated with recombinant FSH (Gonal F, Serono, Aubnne, Switzerland) 150 IU/day on day 2 of withdrawal bleeding. Serial ultrasound examinations and evaluation of serum E2 levels were used to assess ovarian response, and then gonadotropin dose adjustments were done as required. Human chorionic gonadotropin (pregnyl, Organon, Oss, the Netherlands ) 10,000 IU was administered when at least two follicles reached a mean diameter of 18 mm.

Oocyte retrieval was performed 34-36 hours after hCG administration and conventional insemination or ICSI was performed as clinically appropriate.

In 187 patients allocated to fresh ET group, ET were performed on the day 2. Embryos were transferred under ultrasound guidance, with a C.C.D. embryo transfer catheter (Laboratory C.C.D., Paris, France). Luteal support with progesterone in oil (Progesterone, Aburaihan Co., Tehran, Iran) 100 mg daily IM was started on the day of oocyte retrieval and continued until the documentation of fetal heart activity on ultrasound.

In 187 patients allocated to FET group, cryopreservation of all embryos were undertaken with vitrification by Cryotop method and after two months, embryos were transferred.

The protocol for the Cryotop vitrification of embryos was described previously (Kuwayama et al., 2005; Kuwayama, 2007).

After a two-step loading with equilibration solution containing 7.5% (v/v) ethylene glycol and 7.5% (v/v) dimethyl sulfoxide, and vitrification solution containing 15% (v/v) ethylene glycol, 15% (v/v) dimethyl sulfoxide and 0.5 mol/L sucrose, embryos were loaded with a narrow glass capillary onto the Cryotop in a volume of < 0.1 µL . After loading, almost all the solution was removed to leave only a thin layer covering the embryos, and the sample was quickly immersed into liquid nitrogen (LN). Subsequently, the plastic cap was pulled over the film part of the Cryotop, and the sample was stored under LN. At warming, the protective cap was removed from the Cryotop while it was still submerged in LN and the Cryotop was immersed directly into a 37˚C medium containing sucrose. The embryos were then sequentially incubated in diluents solution before further in vitro culture for transfer.

Patients were prepared for ET with oral E2 to attain endometrial thickness ≥ 8 mm and triple line pattern on ultrasound scans. At that time, patients were given 100 mg of IM progesterone in oil daily and ET was preformed three days later under abdominal ultrasound guidance as described earlier. Oral E2 and progesterone were continued until documentation of fetal heart activity by ultrasonography.

Phase 1
Phase 2
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
In Vitro Fertilization
  • Procedure: freezing embryos by vitrification
    vitrification by Cryotop method
    Other Name: cryopreservation of embryos
  • Procedure: fresh embryo transfers
    fresh embryo transfers
    Other Name: embryo transfer using fresh embryos
  • Drug: buserelin
    Daily administration of 500 µg subcutaneous buserelin from day 21 of menstrual cycle; reduce to 250 µg daily when ovarian suppression is confirmed.
    Other Name: suprefact
  • Drug: recombinant FSH
    gonadotropin stimulation with rFSH 150 IU/day from day 2 of menstrual cycle
    Other Name: Gonal F
  • Drug: human chorionic gonadotropin (pregnyl)
    hCG 10,000 IU is administered when at least 2 follicles reach a mean diameter of 18 mm.
    Other Name: pregnyl
  • Active Comparator: frozen-embryo transfer
    In this group all embryos are cryopreserved and two months later embryo transfer will perform.
    • Procedure: freezing embryos by vitrification
    • Drug: buserelin
    • Drug: recombinant FSH
    • Drug: human chorionic gonadotropin (pregnyl)
  • Active Comparator: fresh embryo transfer
    In this arm fresh embryo transfers are performed on day 2 or 3.
    • Procedure: fresh embryo transfers
    • Drug: buserelin
    • Drug: recombinant FSH
    • Drug: human chorionic gonadotropin (pregnyl)
Aflatoonian A, Oskouian H, Ahmadi S, Oskouian L. Can fresh embryo transfers be replaced by cryopreserved-thawed embryo transfers in assisted reproductive cycles? A randomized controlled trial. J Assist Reprod Genet. 2010 Jul;27(7):357-63. doi: 10.1007/s10815-010-9412-9. Epub 2010 Apr 6. Retraction in: J Assist Reprod Genet. 2013 Sep;30(9):1245.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
Unknown status
December 2009
February 2009   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • age < 38
  • normal day 3 FSH
  • classified as high risk for OHSS
  • has ≥ 15 follicles with a mean diameter ≥ 12 mm per each ovary
  • E2 levels on the day of hCG administration > 3000 pg/mL
  • undergoing her first assisted reproduction treatment cycle

Exclusion Criteria:

  • who does not have good-quality embryos appropriate for cryopreservation
Sexes Eligible for Study: Female
18 Years to 38 Years   (Adult)
Contact information is only displayed when the study is recruiting subjects
Iran, Islamic Republic of
Not Provided
Not Provided
abbas,aflatoonian, YazdRCCI
Yazd Research & Clinical Center for Infertility
Not Provided
Principal Investigator: abbas aflatoonian, M.D. Research and Clinical Center for Infertility
Principal Investigator: homa oskouian, M.D. Research and Clinical Center for Infertility
Yazd Research & Clinical Center for Infertility
April 2009

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP