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IVF technology is improving by leaps and bounds and many exciting advances have taken place recently.
Many of these are now available in India, and these include the following:
One of the major problems with IVF today is the low pregnancy rate after successful embryo transfer. The reason why such few embryos implant successfully (only one of 10 embryos will become a baby) is one of the things we really do not understand today. Dr. Jacques Cohen from New York believes this is because the surrounding shell of the embryo (called the zona pellucida) hardens when it is cultured in the laboratory. Some clinics therefore use "embryo surgery" (called zona drilling or assisted hatching) to "soften" the shell of the embryo, and they believe this helps in increasing pregnancy rates by improving implantation rates, since embryo hatching is facilitated. Hatching can be done using an acid (acid Tyrode's) or with a laser. However, assisted hatching has not been shown to be helpful when used on a routine basis for all patients, and most doctors feel that it should be utilized only when needed for example, for the small proportion of patients who have a thick zona or perhaps, for patients over 40 years of age, or those who have had repeated implantation failures. Unfortunately, many IVF vlinics perform assisted hatching indiscriminately, primarily in order to enhance their revenue.
Fig 9. Assisted hatching. The embryo is held securely, and a carefully controlled stream of acid is blown through a fine pipette in order to drill a hole in the zona (shell).
Embryo surgery has also been used for embryo biopsy, for preimplantation genetic diagnosis, in which single cells are removed from the developing embryo, to make sure the embryos are healthy and have no genetic disease. This is described in more detail in Chapter 26.
Embryo multiplication, by removing some of the cells from the embryo and allowing them to divide, can allow doctors to "multiply" the number of embryos formed in vitro. The new embryos can then be coated with a new shell (zona) and then transferred into the uterus. This could help to increase the chances of pregnancy in women who can produce only a small number of embryos.
Other scientists feel that the reason for the poor implantation is the poor quality of the embryo cultured in vitro. They have therefore tried to improve embryo quality in the laboratory by trying to provide it with more natural ("physiological") culture conditions. This is done by a method called co-culture in which the embryo is cultured along with "feeder cells" in the culture dish. These cells provide the embryo with the extra nourishment they need for better growth. Better pregnancy rates are claimed with co-cultured embryos as compared to embryos grown under traditional IVF conditions.
© Dr. Aniruddha Malpani and Dr. Anjali Malpani www.drmalpani.com
Credits: How to Have a Baby: Overcoming Infertility
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