Single Euploid Blastocyst Transfer Recent Technology

IVF patients from Tampa, Tampa Bay, Orlando, Sarasota, Bradenton, Ft. Myers, Naples, and all Florida are treated with the highest technology and attention to detail in the IVF labs of Fertility Center and Applied Genetics of Florida.


Blastocyst Transfer

Improvements in the understanding of the physiology of pre-embryos (pre-embryo refers to the stage of development before differentiation of the inner cell mass into three separate tissue layers) in the first few days of development and the resultant development of embryo culture media capable of supporting prolonged pre-embryo growth in the laboratory have allowed IVF clinics to extend the “in vitro” culture to the fifth and sixth day after fertilization.

An expanded human blastocyst on the 5th day of culture
Copyright: J. Pabon collection


Many IVF clinics culture embryos only for three days.  These clinics may have chosen to do this because it is an efficient way to run an IVF lab.  Dr. Pabon chose to offer prolonged embryo culture and blastocyst transfers from the very beginning of the IVF lab in Sarasota in 1996.   Yes, prolonged embryo culture requires more media, supplies, and work, but the desire was and is to offer the best for our patients.

Extending the culture of embryos allows the team to select fewer embryos for transfer.  Many genetically abnormal embryos reach the third day of culture looking quite normal.  Embryos with the most severe abnormalities often stop dividing and don’t reach the later stages.  Prolonging the culture allows the IVF team to select fewer embryos (1 or 2) for transfer in patients less than 38 years of age and only 1 in patients less than 32 years of age.  The initial drive to extend the culture was to improve the embryo selection and therefore decrease the risk of high order pregnancies (triplet or higher).

The experience gained with prolonged embryo culture allowed our IVF lab to become a pioneer in the Southeastern United States in Pre-implantation Genetic Screening and Diagnosis (PGS and PGD).  A very good lab and IVF team is required as PGS/PGD requires prolonged culture.  Our first PGS/PGD treatment was in 1999-2000.  Since then, the PGS/PGS program has evolved from Day 3 biopsies to Day 5 and 6 biopsies.  Currently, most of our patients choose to do PGS of their blastocysts in order to have more information about each embryo that is considered for implantation and/or long term frozen storage.  Our clinic is the first in Florida to offer single euploid ( proven normal number of chromosomes ) transfers of blastocysts tested at the blastocyst stage for both fresh or frozen/thawed embryo transfers. Our 2012 data has been very encouraging.  Patients that had single euploid blastocyst transfers enjoyed a 75% chance of pregnancy while those that had “all freeze” protocols followed by single euploid transfers achieved a pregnancy in more than 90% of transfers.  The latter includes only patients with normal wombs.

Low Oxygen Embryo Culture System

Dr. Pabon has spared no expense in order to make the laboratory in Sarasota on par with any laboratory in the world.  Our IVF lab uses low oxygen incubators in order to duplicate the normal environment in the human fallopian tube.  In fact, Dr. Pabon is one of first scientists to show that a low oxygen environment is beneficial and is one of the first in the Southeast to culture in a low oxygen environment.

Not all patients require a prolonged embryo culture.

Controversy still exists in the IVF field regarding the optimal length of the in vitro culture period.  The current standard of care is to shorten the culture period to the third day if the patient has few embryos in culture.  The current reasons to prolong the embryo culture include:

1. Waiting for a cohort of embryos (usually more that 4) to differentiate themselves

2. Waiting for differentiation in order to select only 2 embryos for transfer

3. Waiting for the results of the embryo genetic tests (PGS/PGS)



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The Embryology Laser

Our IVF lab made a very significant investment in technology in 2012.  We incorporated a LASER system into our Olympus inverted microscope in order to use light energy to perform assisted hatching and incisions for embryo biopsies.  The laser has replaced the traditional acid method and allows us to perform these procedures more quickly.  The addition of the laser was key in allowing our PGD/PGS program to move efficiently from the traditional day 3 biopsies to the current blastocyst trophectoderm biopsies.

Modern Oocyte and Embryo Vitrification

Another advance that has been implemented since 2010 has been a shift in or cryobiology procedures from slow freezing techniques to vitrification techniques.  Vitrification is a method for freezing biological tissues that protects the tissues from injury that can occur if ice crystals form.  The vitrification techniques “spot freeze” eggs and embryos and essentially turn them into a glassy state preserving them in a sealed tube in liquid Nitrogen at temperatures colder than minus 196 degrees Celcius or minus 321 degrees Farenheit.

Vitrification techniques have increased the pregnancy rates for frozen/thawed embryo transfer to the point that in cases where the patient is hyperstimulated, she may have a higher chance of pregnancy if all the embryos are frozen and transferred  at a later date.  This is referred to as the “All Cryo” or “All Freeze” protocol in our office.

Improved pregnancy rates with Vitrification techniques have also allowed the IVF team to transfer fewer embryos in both the fresh transfer and frozen/thawed embryo transfer patients.