The term in-vitro fertilization (IVF) refers to the medical practice of fusing the male sperm and female ova in a controlled environment such as a petri dish or test tube. However, advances in reproductive medicine have made it easier to use the Petri dishes. IVF is a form of Assisted Reproductive Technology (ART) for individuals contending with infertility.
Normally, an egg and a sperm are fertilized inside a woman’s body, in the uterus. If the fertilized egg attaches to the lining of the womb and continues to grow, a baby is born about 9 months later. This process is called spontaneous or unassisted conception.
In IVF or Assisted Reproductive Technology (ART) however, special medical techniques are used to help a woman become pregnant. It is most often tried when other less expensive fertility techniques have failed.
Some Basic Steps in the IVF Procedure
Step 1: Stimulation
Also called super ovulation or controlled ovarian hyperstimulation
Medicines, called fertility drugs are given to the woman to boost egg production.
Normally, a woman produces one egg per month. Fertility drugs tell the ovaries to produce several eggs.
During this step, the woman will have regular transvaginal ultrasounds to examine the ovaries and blood tests to check hormone levels.
Step 2: Egg or Oocyte Retrieval
This is a minor surgery called follicular aspiration or oocyte retrieval. It is done to remove the eggs from the woman’s body.
The surgery is done as an outpatient procedure in the doctor’s office most of the time. The woman will be given medicines so she does not feel pain during the procedure. Using ultrasound images as a guide, the health care provider inserts a thin needle through the vagina and into the ovary and sacs (follicles) containing the eggs. The needle is connected to a suction device, which aspirates the eggs and fluid out of each follicle. The procedure is done under some form of anesthesia.
The procedure is repeated for the other ovary. There may be some cramping or lower abdominal pain after the procedure, but this should stop after a short period.
If a woman does not or cannot produce any eggs, donated eggs may be used.
Step 3: Insemination and Fertilization
The man’s sperm is placed together with the best quality eggs. This is called insemination.
Eggs and sperm are then kept in the incubator for further development to occur.The sperms most often fertilize the eggs a few hours after insemination.
The doctor or embryologist my inject the sperm directly into the egg if the sperm count is very low or has poor morphology. This is called Intracytoplasmic Sperm Injection (ICSI).
Many fertility programs routinely perform ICSI on some of the eggs, even if things appear normal.
Step 4: Embryo culture
When the fertilized egg divides, it becomes an embryo. Laboratory staff will regularly check the embryo to make sure it is growing properly. Within about 5 days, a normal embryo is expected to have several cells that are actively dividing.
Pre-implantation genetic diagnosis can be done from day 3 to 4 of fertilization for couples having genetic diseases that may be transferred to their offspring. A single cell is removed from each embryo and screened for specific genetic disorders.
Step 5: Embryo Transfer
The embryos are placed into the woman’s womb 3 to 5 days after egg retrieval and fertilization.
The procedure is done in the theatre and anesthesia is often not needed. The doctor inserts a thin tube (catheter) containing the embryos through the cervix into the uterus. Pregnancy results if an embryo implants in the lining of the womb and grows.
More than one embryo may be placed into the uterus at the same time, which can lead to twins, triplets, or more. The exact number of embryos transferred is a complex issue that depends on many factors, especially the woman’s age, quality of the embryos, health status and government policies among other factors.
Unused embryos may be frozen and implanted or donated at a later date.
After embryo transfer, the woman may be told to rest for the rest of the day. Complete bed rest is not necessary, unless there is an increased risk for OHSS. Most women return to normal activities the next day.
Women who undergo IVF must take daily shots or pills of the hormone progesterone for 8 to 10 weeks after the embryo transfer. Progesterone is a hormone produced naturally by the ovaries that prepares the lining of the uterus (womb) so that an embryo can attach. Progesterone also helps an implanted embryo grow and become established in the uterus. A woman may continue to take progesterone for 8 to 12 weeks after becoming pregnant. Too little progesterone during the early weeks of pregnancy may lead to miscarriage.
The woman will return to the clinic so that a pregnancy test can be done after 12 to 14 day of embryo transfer. The test can be done at home.
It is advisable to contact the fertility care provider if the under listed are noticed:
A fever over 38°C
Severe lower abdominal pain
Heavy bleeding from the vagina
Blood in the urine