In order for pregnancy to occur, an egg has to be released from the ovary and unite with a sperm. Normally this union, called fertilization, occurs within the fallopian tube, which joins the uterus (womb) to the ovary. However, in IVF the union occurs in a laboratory after eggs and sperm have been collected. Embryos are then transferred to the uterus to continue growth.
Both fallopian tubes are absent or blocked due to surgery or tubal pregnancy) or infection (STD, or Tuberculosis)
Reduced sperm count or motility (IVF can be normally performed for counts which are more than 5 million per ml. For counts less than 5 million per ml. ICSI is a better option.) Patients where all other treatments such as ovulation induction with intra uterine insemination have proven unsuccessful.
Patients with unexplained infertility where all the investigations performed on the couple are normal, but who still do not conceive with routine treatments.
Patients who have failed to become pregnant inspite of all routine treatments of infertility.
Patients who want to become pregnant by the procedure of embryo and egg donation. In our unit, the success rates of IVF are in the region of 20 to 30%, which are comparable to the leading units in the world.
There are five major steps in the IVF and embryo transfer sequence:
- Monitor the development of ripening egg(s) in the ovaries
- Collection of eggs
- Obtaining the sperm
Putting the eggs and sperm together in the laboratory, and providing correct conditions for fertilization and early embryo growth
Transferring the embryos into the uterus
To control the timing of egg ripening and to increase the chance of collecting substantial number of eggs, fertility drugs are prescribed according to each individual case. Before dertemining the egg retreival schedule, we perform an ultrasound of the ovaries to check the development of eggs and a blood/urine test to measure hormone levels.
The Egg Retrieval Process
The retrieval procedure to obtain the eggs is performed trans-vaginally using a hollow needle guided by the ultrasound image (this is completely comfortable under adequate sedation and local anesthesia). Eggs are gently removed from the ovaries using the needle. This is called "follicular aspiration." Its timing is crucial because the egg will not develop properly if it is collected too early; if too late, the egg also may develop poorly or may have already been released from the ovary and lost.
The eggs are immediately identified by our embryologists in our special IVF laboratory. They are placed with the sperm in incubators to allow fertilization to take place. The eggs are examined carefully at intervals to ensure that fertilization and cell division have taken place; the fertilized eggs are now called embryos.
Embryos are usually placed in the wife's uterus 2 or 3 days after egg retrieval. A speculum is inserted into the vagina to expose the neck of the womb (cervix). The embryos are suspended in a tiny drop of fluid and then very gently introduced through a catheter into the womb, often under ultrasound guidance. The transfer is followed by a resting period, blood tests and possibly ultrasound examinations to verify if pregnancy has been established.
To summarize, the IVF procedure consists of:
Controlled Ovarian stimulation with drugs (GNRH Analogues and Gonadotrophins) to produce many eggs.
Monitoring of follicles and egg development with the aid of vaginal sonography and serial Estradiol hormone estimation.
Administration of HCG injection, (Human Chorionic Gonadotrophins) when the two leading follicles are 18mm in diameter.
Oocyte or egg retrieval under short general anesthesia, 35 to 37 hours after HCG injection.
- Identification and isolation of eggs in the laboratory.
- Sperm collection and processing in the lab.
- Fertilization of the egg with the sperm.
- Embryo formation 2 to 5 days after fertilization.
Embryo transfer of good quality embryos back to the womb, after 2(four cell embryo), 3 (six-eight cell embryo) or 5 (blastocyst stage) days after egg removal.