The Sunday News
IN vitro fertilisation, which has just resumed in Zimbabwe at The Avenues Clinic in Harare, is the fertilisation of a woman’s eggs outside her body in a laboratory, resulting in what has been termed a test tube baby.
The procedure has been carried out in Zimbabwe before but not since 2004. It was successfully conducted at The Avenues Clinic in the 1980s and 1990s by obstetrician Dr Tony Robertson, who is now retired. More than 50 children, who are now adults, were born as a result.
Dr Robertson and his wife, Fiona, who is an embryologist, are giving advice and support to the new in vitro fertilisation team, which is made up of specialist obstetrician and gynaecologist Dr Tinovimba Mhlanga, and laboratory scientist and embryologist Tinei Makurumure, both of whom have undergone specialist training in the procedure at the Orange Free State Medical School in Bloemfontein, South Africa.
There are a variety of fertility treatments open to couples who find themselves unable to have children. These include the timing of intercourse, hormone therapy, intra-uterine insemination (IUI), more commonly known as artificial insemination, and in vitro fertilisation (IVF).
The type of treatment depends on the cause of the fertility problem. Various tests have to be done, therefore, before a doctor can recommend the appropriate treatment.
For a pregnancy to occur, an egg must be released from a woman’s ovary and unite with a sperm, which normally enters the woman’s body through sexual intercourse. This union or fertilisation normally occurs within the woman’s fallopian tube.
With in vitro fertilisation a woman’s eggs and a man’s sperms are brought together outside her body in a dish. This means that the eggs and sperms have to be collected in the laboratory for the fertilisation procedure.
To maximise the chances of successful fertilisation outside the body, several eggs are required. Hormones are therefore injected into the woman to stimulate her ovaries to produce a good number of follicles, within which are the eggs.
Without this stimulation, a woman’s ovaries normally only produce and release one egg per month. Prior to beginning the course of injections, medication is given to prevent spontaneous ovulation.
The injections continue daily for between one and two weeks, depending on how the ovaries respond. The ovarian response is monitored through ultrasound scans. Once at least three follicles have reached a size of 18mm, an injection is given to trigger ovulation. About 34 hours after this “trigger shot” retrieval of the eggs is undertaken.
The method used at The Avenues Clinic is that a needle, guided by ultrasound imaging, is inserted through the vaginal wall into the ovaries, where the follicles containing the eggs are punctured and the follicular fluid withdrawn through aspiration.
Usually an epidural, local anaesthetic or sedative is administered to the woman prior to the retrieval procedure. The procedure takes between 30 minutes and an hour. Within a few hours the woman can return home.
The eggs are transferred in the follicular fluid to the laboratory, which at The Avenues Clinic is adjacent to the operating theatre where the egg retrieval is done. After they have been passed through a hatch to the embryologist, their developmental stage is assessed under a microscope.
A sperm specimen obtained from the woman’s husband is washed, to remove semen and inactive cells, and prepared for insemination. Each egg is placed in a dish in a fertilisation medium. After about three hours after oocyte retrieval a defined number of motile sperm cells are added to each dish. Each dish is placed in an incubator, where it is kept warm to mimic conditions in a fallopian tube.
In some patients the sperm quality is predetermined as inadequate to achieve fertilisation. Where this is the case, the embryologist will perform a technique called Intra Cytoplasmic Sperm Injection (ICSI), whereby one sperm is picked up in a needle and injected into the egg.
After 17 hours or more, the laboratory scientist checks each dish for evidence of fertilisation. If fertilisation has occurred in any of the dishes, the embryologist informs the doctor.
The next day the embryologist checks for cell division. If there are two cells, then an embryo is developing. It is transferred to a growth medium.
On the third day the embryo may have developed to the four to eight cell stage. A decision has to be made then on whether to transfer the embryo into the woman’s womb at that stage or wait until the fifth day, which is the most common time at which to do the transfer.
At The Avenues Clinic, a single embryo or in some cases a maximum of two embryos are transferred to the mother’s womb. Where two embryos are implanted, the hope is that this will result in the birth of at least one child but not more than two.
The remaining embryos can be frozen in liquid nitrogen with the consent of the patients. They can, should the parents decide they want more children, be transferred to the mother whenever she is ready to have another child. The success rate with frozen embryos may be higher than with newly formed embryos.
Although these embryos could survive indefinitely in the liquid nitrogen, the practice followed by the team at The Avenues Clinic is, unless the parents say they do not want them kept, to keep them for 10 years and then destroy them. This is in line with United Kingdom legislation. There is no Zimbabwean legislation governing the issue.
The disposal of embryos is a contentious issue for those who believe that human life begins at conception. The Catholic Church is opposed to IVF because it considers the destruction of embryos to be the taking of human lives and because it believes that conception should not be separated from the normal means of achieving this, which is through a husband and wife expressing their love for each other through sexual intercourse.
There is no consensus among other religions on the morality or otherwise of the procedure. According to Wikipedia one Islamic authority concluded that it was permissible as long as there was a good medical reason for it and it only involved the sperms and eggs of a husband and wife.
In some countries left over embryos can be donated to another woman, which again poses moral and ethical issues. In some countries they can be donated for research, which means they will never become a fully developed baby, again throwing up issues of morality and ethics, if the embryo is already considered a human being.
The first baby in the world to be conceived through in vitro fertilisation, Louise Brown, was born in 1978 in Manchester in the United Kingdom. As a world first, there was a lot of publicity around this birth. The second successful test tube baby birth occurred 67 days later in India.
There are now thousands of people who were conceived through IVF, 52 of them, who are now adults, in Harare.
The revival of the IVF procedure at The Avenues Clinic offers hope to Zimbabwean couples who are unable to have children of their own in any other way to take advantage of this procedure. Previously they would have had to go to South Africa or some other country for it. Having the procedure done locally is not only cheaper but more convenient, as it is done on an out-patient basis with no overnight stay at the clinic normally required.
The full IVF team is made up of Dr Mhlanga and Dr Robertson, both of whom are specialist obstetricians and gynaecologists, Mr Makurumure and Mrs Robertson, who are the embryologists, and Sr Florence Marechera, a nursing sister who is the programme’s counsellor and coordinator.
Dr Robertson and Mrs Robertson, both of whom are retired, are temporary members of the team, as, while they are enthusiastic about the resumption of IVF in Zimbabwe, they have indicated their wish to withdraw from it to continue their retirement once Dr Mhlanga and Mr Makurumure no longer require their assistance.
- (Issued on behalf of The Avenues Clinic by MHPR Public Relations Consultants)
