General Information:

This treatment Consist of  growing human embryos in the laboratory to "blastocyst" stage before transferring them into the uterus following in vitro fertilization. This new technique has potential advantages and disadvantages, however, these cannot be fully evaluated until there is widespread application by many infertility centers to confirm results and analyze risks. We provide blastocyst program to infertile couples undergoing IVF or ICSI who wish to avail themselves of its potential benefits but who also understand its potential risks.

Special Information :

Fertilization of an egg by a sperm occurs soon after its release from the ovary (ovulation) into the fallopian tube to form a single cell embryo(zygote) containing the generic material of the sperm and egg. The zygote then divides progressively into a multi-cell embryo. When the embryo contains about 12-16 cells, it is called a "morula". After 5-7 days, the embryo contains many cells and forms a cystic cavity within its center. At this stage, the embryo is called a "blastocyst". In the human, the egg is fertilized in the fallopian tube near the ovary. The developing embryo descends through the tube into the uterine (endometrial_ cavity about three to four days after ovulation when it is a the morula stage. The embryo sits in the uterine (endometrial) cavity for about two days during which time it develops into a blastocyst. The blastocyst invades (implantation) the uterine lining about the fifth or sixth day after ovulation so that it can develop a blood supply (placenta) that will allow it to continue to grow into a fetus and then a baby.  

Until recently, culture of embryos, in the laboratory, to the blastocyst stage was very difficult because the several culture media that were used to supply nutrients to the embryos were inadequate for extended embryo growth in the laboratory. Therefore, many embryos died before they developed into blastocysts. New culture media are now available that sustain embryo growth in the laboratory for many days. Some IVF centers have begun laboratory culture of embryos to the later blastocyst stage before transferring them into a woman's uterus in an attempt to balance the pregnancy rate. The last stage Blastcyst are transferred to reduce the risk of multiple gestations.
Blastocyst transfer has several theoretical advantages:

•  Transfer occurs closer to the natural time that an embryo enters the uterus when the uterine lining may provide a better environment for the embryo.

• Allowing embryos to develop in the laboratory for a longer period of time may be a better method for selecting the most normal embryos tht would be more likely to implant . Theoretically, an embryo that dies in laboratory before it develops into a blasotcyst would also not have continued to develop in the uterus.

• Because blasotcyst are “selected” as the embryos most likely to implant and become pregnancies. Fewer embryos need to be transfer to maintained an acceptable pregnancy rate. In theory, the pregnancy rate per transfer should be much higher when blasotcyst embryos are transferred on day 5-7 then when earlier stage embryos are transferred on day 2 or 3.

• Transfer of fewer embryos should decrease the incidence of multiple birds. This may well be the most important reason to consider blasotcyst transfer .

Blastocyst transfer has several theoretical Disadvantages:

• The primary risk of attempting blasotcyst transfer is that some embryos will die in the laboratory .Therefore , the total no. of embryos available for transfer and freezing will be less. Unfortunately , some couples under going IVF will have all there embryos die in the laboratory and will not have any embryos available for transfer.

• Blasotcyst transfer probably offers more value to couples with a large no. of embryos (at least 8) .If the starting no. of embryos is low ,then the chance of having no embryos for transfer is much higher .

• No one knows whether some of the embryos that die in the laboratory would have develop into a normal pregnanacy If they had been transferred into the uterus at an earliest stage.

• Blasotcyst transfer does not guarantee a normal pregnanacy .We expect thet some pregnancies will miscarry and some babies will develop birth defects similar to that which occurs in couples that are able to achieve pregnanacy naturally.

• Excess blasotcyst may be frozen an some of them will not survive the freeze –Thaw process when utilized for alater attempt at achieving pregnancy.