Blastocyst transfer is one of the options available in in-vitro fertilization (IVF). It involves implanting one or more blastocysts in the womb. A blastocyst is an embryo that has developed for five to six days after fertilization of the egg in an incubator in the laboratory. Blastocyst transfer may be recommended for younger women and women who have had previously tried IVF, but were unsuccessful in getting the embryos to implant in the womb.
IVF is an option for women who fail to get pregnant by conventional means due to a wide range of reasons. These can include blocked fallopian tubes, hostile cervical mucus and problems with the male sperm. There are various different options with IVF. A fertility specialist can recommend the best one according to each patient's circumstances.
Blastocyst transfer is a process that takes some time and should be closely monitored. First, the woman's natural hormonal cycle is suppressed using hormonal drugs, either by self-injection or intra-nasally, for approximately two weeks. After this, follicle-stimulating hormone is administered, again by self-injection, for about 12 days. This stimulates the production of more eggs than normal.
A day or two before the eggs are harvested, a hormone injection is administered to allow the eggs to mature. They are then removed, usually under conscious sedation, from each ovary. The eggs are then mixed with the partner or donor sperm in the laboratory and left for 16 to 20 hours for fertilization. Those that are fertilized are placed in an incubator. In the case of embryo transfer, the most viable embryo or two will be transferred into the womb two to three days later.
In the case of blastocyst transfer, this will occur only five to six days later. This may increase the chances of successful pregnancy. In an unassisted pregnancy, this is the stage at which implantation occurs in the uterine lining. There is a risk, though, that the embryos will not develop into blastocysts in the incubator. Some develop only until day two in the laboratory.
The chance of successful pregnancy with IVF differs from patient to patient, with numerous factors affecting outcome, most important of which is age. Depending on the number of blastocysts that are inserted during blastocyst transfer, there is a high incidence of multiple births with IVF. It is vital that prospective mothers discuss this with their medical practitioner before embarking on IVF by any method, be it embryo or blastocyst transfer.
