Eulalee Thompson
THE TECHNIQUE of in vitro fertilisation, perfected by British medical researchers Patrick Steptoe and Robert Edwards, has become a beacon of hope for infertile couples. Even more so, after their research made possible the birth of Louise Brown, the world's first test-tube baby on July 25, 1978.
This sophisticated technique, often described as producing a test-tube baby, is now available at the newly-opened University Hospital of the West Indies' in vitro fertility laboratory. Dr. Joseph Frederick, lead clinician who pioneered in vitro fertilisation (IVF) here, said persons with complicated infertility problems can benefit from the technique.
IVF involves the collection of eggs from the woman and spermatozoa from her partner and uniting them in a petri dish in the laboratory. When fertilisation takes place in the dish and an embryo is created, it is transferred to the woman's womb.
Before the eggs are collected, Dr. Frederick said the woman is given drugs such as buserelin and lupronilyde that will downregulate (or quieten) the ovaries by interfering with the action of the pituitary gland. These "downregulating drugs", usually injected in the muscle of the leg, are prescribed for 21 days. The injections usually start on the first or 21st day of the menstrual cycle and they will temporarily give the woman symptoms of menopause such as hot flashes, dryness of the vagina and sweating.
After an ultrasound scan confirms that the lining of the womb is thin and the ovaries are quiet, the patient can begin the second course of drugs. The drug (the gonadotrophins such as pergonal and metrodin) is prescribed for another 11 days and is really a fertility hormone that stimulates the ovaries to produce many more than one egg per menstrual cycle.
The eggs are collected in the operating theatre adjoining the laboratory. Dr. Frederick explained that a probe with a long needle attached is used to recover the eggs from the ovaries.
The recovered eggs are passed quickly to the embryologists. Embryologists Clotelle Frederick and Gina Aldis say the eggs are examined under the microscope. The healthy ones are inseminated with about 200,000 spermatozoa collected on the same day from the partner. They are left overnight in the incubator and checked in the morning for fertilisation. The fertilised egg and sperm produce an embryo which is usually transferred to the womb on the third day after collection.
Dr. Frederick said the UHWI in vitro fertility laboratory will be transferring three eggs to each woman. He expects that at least two of them might "catch" producing twins, but there is the chance for triplets.
After transfer, more hormonal drugs are given to prepare the lining of the womb for implantation of the embryos. Two weeks later a pregnancy test is done.
The UHWI's in vitro fertility laboratory also contains the Intracytoplasmic Sperm Injection (ICSI) which Dr. Frederick said has been the treatment of choice for infertile men since 1993. Men with low sperm count (less than five million sperms per millilitre) or not very motile sperms, or who had tried to reverse their vasectomy but failed, can benefit from this technology. The ICSI is the injection of a single spermatozoon into each egg. At the time that the male spermatozoa are being collected (sometimes by biopsy since Dr. Frederick said that the semen of some infertile men contains no spermatozoa), the female is prepared for egg collection.
