In vitro fertilization (IVF) is a method of infertility treatment in which an egg and sperm are joined in a laboratory container ("in vitro" means "in glass"). This is in contrast to normal "in vivo" conception, in which fertilization occurs in the fallopian tube of a woman's reproductive tract (Harris, 2004).
A woman's eggs are removed, fertilized by sperm in a glass dish with nutrients in a lab, and then put into her uterus.In vitro fertilization is a way to help couples who are having trouble getting pregnant and is a form of assisted reproductive technology (ART). ART uses special methods to help couples get pregnant and involves handling both the woman's eggs and the man's sperm. A couple is considered to be infertile if they have not been able to get pregnant after trying for at least 1 year (Harris, 2004).IVF has been found advantageous in addressing infertility issues even for couples suffering from these conditions:1.
A woman's fallopian tubes are blocked, which means the sperm cannot reach the egg. Fertilization normally takes place in the fallopian tubes. Infections (especially sexually transmitted diseases) or prior surgery may cause scarring in the fallopian tubes or other reproductive organs and block the sperm from reaching the egg or prevent the embryo from implanting in the uterus (Saylor, 2007).2.
The woman has endometriosis, which is a disease when tissues of the endometrium are growing outside the uterus. Endometrium is the lining of the uterus.3. The male partner has no sperm or low sperm counts. The normal number of sperm present in just one milliliter (ml) of semen is over 20 million. A man with only 5 to 20 million sperm per ml of semen is considered subfertile, a man with fewer than five million sperm per ml of semen is considered infertile (Carson-DeWitt, 2008).
4. There are problems with the cervix, such as an infection. The cervix is the opening from the vagina into the uterus through which the sperm must pass. Mucus produced by the cervix helps to transport the sperm into the uterus (Carson-DeWitt, 2008). Injury to the cervix during a prior birth, surgery on the cervix due to a pre-cancerous or cancerous condition, or scarring of the cervix after infection, can all result in a smaller than normal cervical opening, making it difficult for the sperm to enter. Furthermore, any of the above conditions can also decrease the number of mucus-producing glands in the cervix, leading to a decrease in the quantity of cervical mucus.
5. The woman produces antibodies which kill the sperm. . Certain infections can also serve to make the cervical mucus environment unfavorable to the transport of sperm, or even directly toxic to the sperm themselves (causing sperm death).
Some women produce antibodies (immune cells) that identify sperm as foreign invaders (Carson-DeWitt, 2008).6. The cause of infertility is not known. IVF can also be utilized if there is no assignable cause based from the various tests done on the couple as long as the procedure is deemed safe.There are two other ART techniques that have been developed in recent years.
Gamete intrafallopian tube transfer (GIFT) and zygote intrafallopian tube transfer (ZIFT) both involve retrieval of multiple ova and semen. GIFT allows fertilization to occur in the fallopian tubes while ZIFT allows fertilization and growth in the laboratory up to the zygote stage before the zygotes are placed in the fallopian tubes. IVF still holds an advantage to these two newer techniques when the procedure is trying to address infertility issues resulting from a blocked fallopian tube or any other condition that will prevent the embryo from being transported to the uterus safely, the stage of conception which GIFT and ZIFT are dependent on.
