Embryo Culture and Catheter Loading

A Survey for Embryologists in the IVF Unit:
It is widely accepted that the technique of embryo transfer has a crucial impact on the success of implantation in IVF. Discussions with clinicians from different IVF units have revealed that embryo transfer is performed differently in different clinics. This section will be the first part of the survey.

In addition, it seems that at present there is no uniform practice regarding the preferred oxygen concentrations (5% or 20%) to be used in human embryo culture systems. Studies that evaluated the effect of oxygen concentration on embryo development in the human are controversial.

This survey, proposed by Irit Granot PhD, Laboratory Director and Research Coordinator of the IVF Unit, the Kaplan Medical Center, Rehovot, Israel, Gabor Vajta, MD, PhD, DSc Vajta Embryology Consulting, RVT, Australia, and Anat Safran, PhD, Apirion - Embryology Consultation (Israel), Scientific Director, InviMed, European Center of Motherhood, Warsaw, Poland , will reveal the most common techniques used for this procedure.

Who loads the catheter?
  • The embryologist
  • The physician
  • Both


What is the preferred catheter in your unit?
  • The orifice is on its top
  • The orifice is on the side
  • The one who marker for clear ultrasound view


In which medium do you transfer the embryos?
  • Hepes buffered medium in all cases
  • Blastocyst medium in all cases
  • Different medium depending on the embryo stage
  • Other


Do you wash the catheter before loading the embryos?
  • Yes
  • No


How are the embryos loaded into the catheter?
  • Medium-air-embryo
  • Medium-air-embryo-air-medium
  • Medium with embryo and no air in between
  • Fill catheter with medium and load embryo at the end
  • Other


When transferring two or more embryos, do you load more than one embryo in the same drop?
  • Yes
  • No, there is air between each drop of medium containing an embryo


What is the final volume of medium in the catheter?
  • Up to 0.3 ml.
  • 0.3 - 0.5 ml.
  • 0.5 - 0.7 ml.
  • More than 0.7 ml.
  • Other


In general how long are the embryos in the catheter from loading to transfer?
  • 15-30 seconds
  • 30-60 seconds
  • More than 60 seconds
  • Other


What is the rate at which embryos are injected into the uterus:
  • Rapid, to avoid attachment to the wall of the catheter
  • Very slow, very careful
  • No special care is needed


Do you check the catheter after embryo transfer to make sure the embryos did not remain in it?
  • Yes
  • No


If you check the catheter, how do you check it?
  • Observe under the microscope only
  • Observe under the microscope and then wash the catheter
  • I do not check it


If you check the catheter, how do you wash it?
  • Aspirate medium and expel it
  • Disconnect syringe, aspirate air, reconnect syringe, aspirate medium and then expel contents of catheter
  • Other
  • I do not check


In your IVF laboratory, is reduced (5%) O2 concentration used in your embryo culture system?
  • No, only two-gas system (6% CO2 in air) is used
  • Both three (6% CO2; 5% O2 89% N2) and two - gas systems are used
  • Only three - gas system is used
  • Other


At what stages of embryo development are conditions of reduced O2 concentration used?
  • Days 1 - 3 (followed by day 2-3 transfers)
  • Days 1 - 3 (followed by day 5-6 transfers)
  • Days 3 - 5,6 (followed by day 5-6 transfers)
  • Days 1 - 5,6 (followed by day 5-6 transfers)
  • Not used at all


When providing low O2 concentration, what type of media is used?
  • One step media
  • Sequential media
  • Both
  • Not used


Reduced O2 concentrations used for:
  • The entire IVF population
  • Poor responder patients
  • Patients with repeated implantation failures
  • Patients intended for Blastocyst transfer
  • Not used at all


When culturing under conditions of reduced O2 concentrations, do you apply this approach to:
  • The entire cohort of the patients chosen
  • The embryos are equally divided between the two O2 concentrations
  • Not used at all


If you use single medium for blastocyst culture, do you change medium during culture?
  • No medium change
  • Medium change on Day 3
  • Medium change on Day 3 and 5
  • Medium change on Day 1, 3 and 5
  • Sequential media are used


When growing embryos to the blastocyst stage, do you grow them:
  • Single from day 0-5
  • In groups from day 0-5
  • Single from day 0-3 and in groups further on
  • Other
  • We do not grow embryos to blastocysts