In Vitro Fertilization (IVF) Process
In Vitro Fertilization (IVF) is a method in which an egg is fertilized with a sperm outside the body, in a laboratory dish, and then implanted in the uterus. It is a part of Assisted Reproductive Technology (ART), which is opted by couples in the event of failure to conceive due to infertility.
The term ‘in vitro’ is a Latin terminology which means ‘within the glass’, as earlier all the laboratory apparatus was made of glass, unlike today. In the process, ovulation is controlled by administering hormones, and then the ova is removed from the woman’s ovaries to be fertilized externally, with a sperm donated by the male.
Procedure
When a couple opts for IVF, they have to undergo initial tests. These screening tests are done for both partners. The woman has to undergo a test for ‘ovarian reserve’ before any medication is given. Third day FSH testing is done in which the baseline of follicle stimulating hormone is checked on the third day of the menstrual cycle. An elevated baseline, that is a diversion from normal FSH levels indicates a reduction in the ovarian reserve, that is the number of eggs. Determining this, helps the doctors learn, whether a woman will respond to the administration of drugs when stimulated to produce eggs. The success rate of the process depends on the number of eggs that are retrieved on stimulation.
Step of the process
Stimulation: A woman is administered with fertility drugs. These drugs stimulate the ovaries to produce several eggs, rather than the normal one egg per month.
Egg Retrieval: This involves a small surgical process called ‘follicular aspiration’. In this process, with the help of an ultrasound, a doctor inserts a needle through the woman’s vagina to reach the follicles in the ovaries, which contain the eggs. The needle is connected to a suction apparatus, which helps in aspirating the eggs along with some fluid. This process is carried out for both the ovaries. The procedure is relatively painless. However, some women may develop cramps after the surgery.
Insemination and Fertilization: The eggs are stored at controlled temperatures before fertilization. The best quality eggs are then mixed with the sperm obtained from the male partner. This process is artificial insemination. After a few hours, the sperm enters the egg and this is known as fertilization. If the chances of fertilization are low, doctors opt for direct injection of the sperm into the egg, known as, intracytoplasmic sperm injection (ICSI).
Culturing the Embryo: The fertilized egg undergoes stages of division to form an embryo. These stages of division are carefully monitored by the doctors or lab technicians, to assure successful development of the embryo. The embryo has to be maintained in extremely rigid parameters of temperature and also sterility to avoid any sort of contamination. In this stage, the embryo is also screened for genetic disorders. It is necessary to know whether the child will have a healthy genetic constitution, only then can the embryo be implanted.
Implantation or Embryo Transfer: The embryo is implanted in a woman’s womb three to five days after fertilization. In this step of the IVF process, the doctor inserts a thin tube called the catheter through the cervix, into the womb. The catheter contains embryos. Success rate of the process depends on the embryo sticking to the womb. Sometimes implantation of more than one embryo results in twin or triplet pregnancy.