Δευτέρα, 28 Σεπτεμβρίου 2009

Excepts from “The search for excellence in the IVF Lab.”



From my talk Sat 19th Sept., Mitera Hospital

"More than 10,000 IVF procedures are performed each year in Greece.
We have come so very far since the birth of Louise Brown 30 years ago (she’s a mother herself now).

The technology has progressed to the point where getting eggs and sperm and having them joining to make an embryo is no longer the hurdle it once was.

But with restrictions in many european countries on the number of eggs that can be fertilized....or the number of embryos that can be transferred - how can we choose the best embryo capable of forming a healthy pregnancy?

In some countries only a single embryo is allowed to be transferred-
so if you are going to choose only one embryo it had bettter be the best!!!

Picking a healthy embryo from the group growing in the dish remains an inexact science-
Today this process is based upon morphology. Most use a very crude grading system based essentially on the speed of division of the cells and on how regular the cells appear.
This yields a rough system with a grade from 1-5. This would be like your doctor looking at you from across the street and estimating if you were healthy. You’ll get correct information only some of the time.

The technique of PGS (preimplantation genetic screening) where we biopsy a growing embryo and test its genetics has shown that 1/2 of apparently good looking embryos are genetically abnormal and incompatible of leading to a living baby.
So, if we could genetically screen for the best embryos wouldn't this increase the IVF success rate?

Well it's debatable..., PGS is an invasive technique that requires 1 or 2 cells to be taken from the embryo growing in the IVF lab and its DNA tested.

After years of implementation in IVF units all over the world, this technique- has many drawbacks and in recent scientific papers its effectiveness questioned.

But Metabolomics is the study of the small-molecule metabolite by-products left behind from cellular processes and could hold the key to choosing the best embryo:

The concept is that by measuring all the by-products of the cells metabolism you can get a snapshot of the physiology of a cell or embryo and that translates to health.

Researches are looking to turn this new science of metabolomics into a non-invasive test to pick the healthy viable embryo from the dish and increase the chances of pregnancy.

This Idea is not new! When I was at Hammersmith Hospital, London-in the late 1980's, I had the pleasure of meeting Henry Leese a pioneer in embryo metabolism. Working with a friend and colleague of mine, Joe Conaghan, they looked at sugar uptake of the embryo and related this to its viability.

This primitive methology took weeks -by the time the biochemical results came back the embryos had already been chosen for embryo transfer to the patient and she was expecting her pregnancy test results.

Now this test takes 2 minutes

The goal of the technology is to identify metabolic differences in viable verses non-viable embryos so only the highest quality embryos can be selected for transfer in IVF.

This non-invasive test analyzes biomarkers in normally discarded culture media. The biomarkers are quantified using spectroscopic analysis and advanced bioinformatics.

A recent report concluded that detectable differences exist in the metabolomic profiles found in culture media obtained from embryos that cause pregnancy compared to those that do not.

The reported metabolic parameters were established using two different forms of spectroscopic analysis, Raman and Near Infrared (NIR) spectroscopy, with media samples obtained from three different IVF programs. The metabolomic method achieved high sensitivity and specificiity >85%.

That is, they can predict if an embryo will give a pregnancy or not 85% of the time!!!! "

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