Treatments
In the last 50 years it has become increasingly more possible to treat at least some forms of infertility. Hormonal imbalances concerned with female ovulation can be corrected with “fertility drugs”. Some women do not make enough FSH to stimulate the release of follicles from the ovary. Synthetic FSH hormone can be used to replace natural FSH, therefore bringing about ovulation and hopefully pregnancy (Jones 1991). Surgery may be needed if there is a physical blockage in either the male or female, which causes a barrier to sperm movement.
Artificial Insemination
This is the oldest and simplest treatment for infertility. This technique simply involves placing sperm into the female reproductive tract. Used in cases of low sperm count in the male, where the male is normally fertile but for some reason is not producing sufficient sperm to result in pregnancy. The male may donate sperm; the sperm cells are then concentrated and introduced into the uterus of the female. This technique is widely used in cattle and domesticated animals (Purves, Sadava et al 2001)
In Vitro Fertilisation - IVF
The first successful human birth from IVF, carried out by Patrick Steptoe and R. G. Edwards, did not take place until 1978 (). Candidates who take up IVF treatments are women who suffer from blocked or absent fallopian tubes, males with low sperm counts or unexplained infertility between couples. The procedure involves first treating the female with follicle stimulating hormones (FSH) that stimulate the follicles within the ovary to mature. Mature ova are then recovered via needle aspiration. Sperm is then collected from the male and prepared. The ova and sperm are combined in a culture medium where fertilisation takes place in vitro (outside the body). Fertilisation usually occurs within 12-48 hours (Purves, Sadava et al 2001).
The potential embryos are then placed in a growth medium and are observed periodically for cell division into two-cell, four-cell and eight-cell stages (see diagram on page 4). During this time the female receives progesterone, which prepares the lining of the uterus for implantation. The embryos are introduced to the uterus via the cervix.
If the procedure is successful, an embryo will implant itself into the uterine lining and pregnancy will begin. The embryos can be transferred to the uterus at different stages of development. Embryo transfer is performed on day 2 or 3 when the embryo consists of four to eight cells. Research shows that embryos can now be cultured to the blastocyst stage without effects on pregnancy rates. Embryo transfer places the embryos in the uterus at an earlier stage than would occur naturally. With blastocyst transfer, the embryos are placed in the uterus at later stage (day 5 or 6). This fits in with the natural time the embryo would arrive in the uterus. A higher implantation rate has been observed with blastocyst transfer (50%), compared with embryo transfer (25%), however, there is an increased risk of having monozygotic twins through blastocyst transfer ().
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Gamete Intrafallopian Transfer – GIFT
Gamete Intra-Fallopian Transfer (GIFT) is a well-established form of assisted conception treatment, nearly as old as in-vitro fertilisation (IVF). This procedure is used when the upper end of the fallopian tubes are blocked, thus the ova is unable to pass from the ovary into the fallopian tube naturally in order for fertilisation to take place. It is similar to IVF in that the ova and sperm are collected, but these are then injected directly into the upper end of the fallopian tube where fertilisation takes place. Embryonic development then carries on as normal with the blastocyst entering the uterus via the normal route (Purves, Sadava et al 2001).
Zygote Intra-Fallopian Transfer – ZIFT
This is a variation of the GIFT procedure. It differs in that the ova is fertilised before being transferred to the fallopian tube of the female. The fertilised ova or zygote is transferred before cell division takes place (Jones 1991).
Intra-Cytoplasmic Sperm Injection – ICSI
Human in-vitro fertilization (IVF) has been used for some time for the treatment of male infertility but holds little success for severe male fertility problems. In the majority of cases the male sperm are not capable of penetrating the outer coating (zona pellucida) of the egg, so fertility is not possible. This procedure was hailed as a breakthrough in male infertility in the mid 90’s. Men with low sperm counts or poor sperm motility are candidates. It involves injecting a single sperm via a micro needle, directly into the ova that is held in place by a glass suction pipette. The healthiest looking sperm are selected for this procedure. The success rate of this procedure is around 25%. Those patients benefiting from ICSI are the patients with previous failure of fertilisation or low incidence of the fertilisation using IVF (www.britannica.com).
Medical risks and technical difficulties
Conception through IVF techniques can be a highly lengthy process. The success rate is low, around 20 –30% effective. Implantation of the embryo or embryo’s is the main problem. If implantation does occur, early miscarriages often take place. There is a greater risk of multiple pregnancies occurring with the use of IVF. Twins may not pose much of a problem to couples desperately trying to conceive, but triplets or more can present problems –risk of miscarriages, premature birth and death are all greatly increased (Jones 1991).
The long-term safety of the Intra-cytoplasmic sperm injection is still unclear. It offers hope to men with severe fertility problems .It is therefore thought that there is an increased risk of male infertility in the offspring. As the technique is only 10 years old, the outcome will not be fully known until ICSI boys reach maturity (www.britannica.com).
Ethical implications for parents and fetus
The technologies that have allowed couples that would naturally be infertile to have children have also produced serious issues where ethics are concerned. IVF has been plagued with moral, religious and ethical controversy from the outset. Major opposition has come from the Roman Catholic Church, which opposes IVF on three grounds –
- The destruction of embryos not used in implantation and therefore surplus to requirements.
- The possibility of sperm from a donor being used for fertilisation, therefore removing reproduction from the marital context.
- Severing the connection between the conjugal act and procreation (www.britannica.com).
Other more general questions that are often raised regard the experimentation with human fetuses, which are potential human beings. Many IVF clinics now offer embryo freezing to clients. These embryos can be used at a later date if the treatment was unsuccessful or if the couple would like another child. The difficulty arises when the family decides it is complete or if the couple divorce. What is the fate for the frozen embryos? Who do they belong to? Embryos that are surplus to requirements are destroyed.
Some couples with inheritable genetic disorders can have their embryo’s screened to ensure that the offspring will not inherit the unfavourable genes. More recently, couples have been given the go ahead to create a child via IVF to cure their son. The sick son requires healthy bone marrow to overcome his illness. Embryos are screened to see if there is an exact tissue match. Those that are not a match are destroyed. So far this kind of treatment is carried out to help save lives, but also raises the unsettling possibility of parents bearing children not to love and cherish them, but for the harvesting of their tissue ().
In conclusion, infertility studies and treatments will always be controversial. It comes down to personal point of view and public opinion. The ethical debate will continue with questions such as “Are we playing God?” it may also be suggested that the use of antibiotics, immunisation and chemotherapy are also a means of playing God as they have the ability to change and save lives. Scientific knowledge and technological advances will continue to progress and more and more difficult questions will be raised.
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Bibliography
Clegg, C. J. & Mackean D. G., (1994). Advanced Biology: Principles & Applications. John Murray, London
Jones, M., (1991). Infertility, Judy Piatkus, London.
Purves, W. K., Sadava, D., Orians, G H., & Heller, H. C., (2001). Life: The Science Of Biology, 6th Edn, W. H. Freeman & Co, Gordonsville, VA.
Woods, S. & Elstein, M. (September 2003). Infertility and Bioethics. Biological Sciences Review..Volume 16, Phillip Allan Updates, Oxfordshire.
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