In vitro fertilisation

From ArticleWorld

In vitro fertilisation (IVF) is a medical practice that involves many steps and is used to create a pregnancy by the fertilisation of a female egg cell outside of the body with male sperm cells collect from a donor or from the male member of an infertile couple. IVF represents as many as 1% of all live births in the Western world and is a practice that was first perfected more than 25 years ago. In vitro fertilisation is indicated primarily in cases of female infertility but can also be used when a woman has a genetic disorder or when both prospective parents have problems with infertility.

Method

The process of in vitro fertilisation begins when a female, either the prospective mother or an egg donor, undergoes artificial stimulation of the ovaries using hormones in sufficient quantities that multiple eggs are maturing at the same time. When the eggs (ova) are mature, a pelvic ultrasound is used to guide the technician’s needle toward the mature follicles in which the eggs reside. As many eggs as possible are retrieved.

The harvested eggs are then mixed with either the partner’s sperm cells or a donor’s sperm cells in a manner favorable for fertilisation. In cases where the sperm count is low, a single sperm can be injected into an egg using a procedure called intracytoplasmic sperm injection.

The fertilised eggs or zygotes are then incubated by bathing in a special growth medium until they divide and mature into an embryo that consists of about eight cells. At this time, the embryos that appear to be the most viable are aspirated into a needle to be used in the immediate transfer of the embryos into the recipient’s uterus. Some conditions require that some or all of the embryos be frozen for later use, if necessary.

All the while the laboratory part is happening, the doctors make sure that the recipient female has the right uterine conditions for transfer. There is a small window of time where the uterus is favorable for transfer. This is when the eight-celled embryos are transferred from the growth medium via a needle inserted into the uterus through the cervix. The number of embryos transferred varies from clinic to clinic.

For the next two weeks, everyone must wait to see if or how many embryos implanted. Some women take the hormone, progesterone, which helps support an early pregnancy. Other hormones are sometimes used as well.

Results

Overall, the chances of arriving at a healthy pregnancy using in vitro fertilisation are approximately 20-30% per cycle. The actual success rate varies depending on the underlying health factors of the male and the female, as well as on the particular IVF clinic used. Comparing success rates among clinics is difficult as each clinic differs in the type of patient they will select.

The most common complication of an IVF pregnancy is the development of multiple fetuses. Research studies differ; however, the majority of studies evaluating the risk of birth defects in IVF pregnancies show no increased risk when compared to the risk in normal pregnancies.