When infertility is the result of physical problems with the uterus or fallopian tubes, these can often be repaired by means of surgery. Surgery is commonly performed to deal with blocked fallopian tubes or with endometriosis, but it is not limited to these situations.
Intrauterine Insemination (IUI)
In IUI, sperm are inserted directly into the uterus. The aim of treatment is that, once in the uterus, the sperm will be able to fertilize an egg without further assistance. This is particularly appropriate when a post-coital test has identified that sperm are not managing to pass the cervix.
Prior to intrauterine insemination, the sperm can be prepared in a number of ways. This is known as ‘washing’ the sperm, and can involve increasing the concentration of sperm in the fluid to be injected. The washed sperm are then inserted using a catheter.
IUI is a good solution when a couple is sub-fertile but may be able to conceive. It will not be of any use if functional sperm cannot be obtained (e.g. in some cases of total aspermia or azoospermia), nor if the woman is not ovulating.
IVF, ‘in vitro fertilization’, is the fertility treatment that still regularly makes headlines, even decades after its first introduction. IVF is now very common in the UK alone, 10,000 babies are born each year as the result of IVF.
IVF: The basic procedure
The process begins with the collection of eggs from the ovaries. This is done surgically, usually under local anesthetic. Beforehand, doctors will have checked that eggs are present, and will probably have prescribed drugs to cause ovulation. It is normal to use enough drugs to cause multiple ovulation, because the IVF process will only work with a small fraction of eggs.
Sperm is also collected (this process being much simpler than collecting eggs), and the egg and sperm are combined ‘in vitro’ (meaning ‘in glass’, or ‘in a test tube’). The fertilized egg is grown in the laboratory for a while, in which time it will divide once or twice. It is then inserted into the womb.
Commonly, multiple eggs are fertilized during IVF treatment, and several will be inserted into the womb at the same time.
It is expected that most of the embryos will fail to develop (even with multiple implantations only 20-25% of IVF procedures result in pregnancy), and so inserting several improves the odds that at least one will make it. The downside is that occasionally more than one survive, leading to the controversial phenomenon of multiple births following IVF.
While the IVF success rate is currently low, it is likely to increase slowly in the future, as new techniques are developed to improve the process. February 2007 saw reports of a technique called “Comparative Genomic Hybridization”, which one trial suggests could raise the IVF success rate to 70%. It involves checking each egg for likely problems before it is implanted into a patient.
Variations on IVF
IVF has spawned a couple of similar procedures.
- GIFT (‘Gamete Intrafallopian Transfer’)
ZIFT (‘Zygote Intrafallopian Tranfer’)
ICSI (‘Intracytoplasmic Sperm Injection’)
GIFT, ‘gamete intrafallopian transfer’, could be described as IVF which isn’t ‘in vitro’. As in IVF, eggs are extracted and then fertilization is artificially induced but with GIFT this takes place inside the fallopian tubes, rather than in a laboratory. This means that, unlike IVF, GIFT requires healthy fallopian tubes.
The advantages of GIFT over IVF are mainly ethical. Some couples object to the idea of human embryo culture in vitro, on religious or other ethical grounds, and consider that GIFT achieves the same end without putting them in a moral conundrum. ZIFT (Zygote Intrafallopian Transfer) is something of a compromise between GIFT and IVF. With ZIFT, the egg is fertilized in vitro, but it is then immediately transferred to the fallopian tube.
Standard IVF puts sperm and egg in close proximity, but relies on them to achieve fertilization without artificial assistance. If this turns out to be ineffective (for example when there is a severe problem with the mobility of the sperm), then it is possible to inject the sperm directly into the egg. This is what happens during ICSI (intracytoplasmic sperm injection).
Egg donation is another option, mainly appropriate for couples in which the man is fertile but the woman is not. An egg donor is given medication which stimulates hormones, and then her eggs are surgically extracted. They can then be inseminated with sperm and implanted.