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The Impact of Early Embryos Incubation on Pregnancy Rate in IVF (IVF-2010)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified December 2013 by Carmel Medical Center.
Recruitment status was:  Recruiting
Information provided by (Responsible Party):
Martha Dirnfeld, Carmel Medical Center Identifier:
First received: January 25, 2011
Last updated: December 5, 2013
Last verified: December 2013
Frozen- thawed embryos obtained by IVF treatments are transferred to the uterus immediately following thawing or after incubation for additional 24-72 hours. The two methods are routine in IVF laboratories. In this study the investigators would like to compare between these two methods in terms of implantation rate, pregnancy rate and delivery.

In Vitro Fertilization

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: The Impact of Early Embryos Incubation on Pregnancy Rate in IVF

Further study details as provided by Carmel Medical Center:

Primary Outcome Measures:
  • Pregnancy as measured by blood test for beta hCG [ Time Frame: 12 days following embryos transfer ]
    as the usual routine, the women come on day 12 or 13 following embryo transfer to pur IVF unit to get blood teat for beta hCG. When the result show that the beta hCG is above 5 unit/liter we consider it as positive result and the patients is invited for additional blood test 2 days later/

Secondary Outcome Measures:
  • Delivery of baby [ Time Frame: 9 mounth after embryos transfer ]
    We are routinely report to the Israeli ministry of health all the children who were born from our treatment. In this study we will calculate the number of children per thawed embryo transfer.

Estimated Enrollment: 660
Study Start Date: April 2011
Estimated Primary Completion Date: February 2014 (Final data collection date for primary outcome measure)
Group A
Transfer at the day of embryo thawing
Group B
Transfer of thawed embryos 24-72 hours post thawing

Detailed Description:

It has been common practice to cryopreserve surplus embryos achieved during IVF treatment or in other situation that embryos are to be preserved for other situations such as suspected ovarian hyper stimulation syndrome, fertility preservation or patient request.

Embryos are usually frozen on day 2, 3 or day 5-6 at the Blastocyst stage. At the time that thawing is planned, patients' cycle is synchronized and prepared either with hormonal treatment or at the natural cycle.

Not all embryos will always survive the thawing and sometimes they will all degenerate.

Embryos that survive the thawing procedure are assessed and replaced on the day of the thaw or left overnight for better selection and will be replaced only if they continue to divide in vitro.

The advantage of embryo transfer on the day of thaw is that embryo exposure in culture is shortened and embryo selection will be occurring in the womb. On the other hand, overnight incubation may avoid transferring embryos that potentially are not able to divide and are biologically not viable.

Although both attitudes are practiced in different IVF centers, at present there are no prospective randomized studies that have been conducted to advise which intervention is better in terms of pregnancy rates.

The purpose of the present study is to assess which technique will result in better pregnancy rates.


Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

660 IVF patients. patients who are candidates for embryo cryopreservation cycle will be offered to participate in the present prospective randomized study.

After detailed verbal and written explanation on the study protocol they will sign an informed consent and then randomized to 2 groups.


Inclusion Criteria:

  • IVF patient who have thawed embryo transfer and can read understand and sigh on informed consent

Exclusion Criteria:

  • IVF patient who have thawed embryo transfer and can not read understand and sigh on informed consent/ also those whos embryos will not survive freezing- thawing
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01287273

Contact: Martha Dirnfeld, MD 8250335 ext 9724
Contact: Shirly Lahav-Baratz, D.Sc 8250118 ext 9724

Carmel Medical Center Recruiting
Haifa, Israel, 34362
Contact: Martha Dirnfeld, MD    8250335 ext 9724   
Contact: Shirly Lahav-Baratz, D.Sc    8250118 ext 9724   
Principal Investigator: Martha Dirnfeld, MD         
Sponsors and Collaborators
Martha Dirnfeld
Principal Investigator: Martha Dirnfeld, MD Carmel Medical Center IVF Unit
  More Information

Responsible Party: Martha Dirnfeld, Head of IVF Unit, Carmel Medical Center Identifier: NCT01287273     History of Changes
Other Study ID Numbers: CMC-10-0010-CTIL
Study First Received: January 25, 2011
Last Updated: December 5, 2013

Keywords provided by Carmel Medical Center:
pregnancy rate
Pregnancy rate of frozen-thawed embryos of IVF treatments processed this record on April 28, 2017