IVF treatment can be a roller coaster of high hopes and crushing disappointment. Wendy Champagne outlines the emotional and physical toll undertaken by an increasing number of couples in Australia.

It's not something we generally question until well into our thirties- career and wild oats thoroughly harvested - but fertility is a major issue today, with one in every six couples considered infertile.

Consequently, infertility clinics have become big business, and despite their appalling success rate, are attracting 20 per cent more customers every year.

At 35 years old, a successful Sydney magazine editor, Alison, decided she was ready to have a child. After she and her husband David discussed it, they waited for nature to take its course.

They waited and waited and despite maintaining a discipline of precision-timed sexual frequency, it never happened.

Two years and a stream of experts later, Alison's condition was defined as "unexplained infertility" and she decided to enter an IVF program.

Alison's 3 cycles of IVF treatment didn't result in a pregnancy, but three years later - when the young mother who had arranged to give her newborn child to Alison and David for adoption had a last minute change of heart - Alison fell pregnant. It was an "unexplained miracle".

There are women in Australia who have undergone up to 10 cycles of IVF treatment in order to conceive - a remarkable commitment considering the emotional and physical toll it exerts.

So, while government and public debate continues over IVF treatments for single or lesbian mothers, it is important to know exactly what awaits a woman or a man when they enter the world of ART (Assisted Reproduction Technology).

In-Vitro Fertilisation (IVF) literally means fertilisation of egg and sperm in a glass, outside the mother's body. Taking the example of a couple, the first step in a cycle of IVF would involve a consultation with a doctor at an IVF clinic and blood tests for Hepatitis B, C and Rubella.

The first major procedure for the woman is a daily course of hormone injections to stimulate the ovaries to produce more eggs than usual. The growth of the eggs is monitored through an ultrasound probe inserted into the vagina at each visit. Once the eggs are judged mature, which is usually a couple of days after ovulation, another hormone is administered to cause "final maturation" before retrieval.

If a large batch of eggs was not harvested from this first round of hormone injections, the women must wait two months then go again. If she was lucky enough to produce sufficient eggs, "collection" is arranged. A patient can choose to have her eggs collected under general anaesthetic at a hospital or sedation at the clinic. With the ultrasound probe in place to guide the procedure, a hollow, thin needle is guided through the vagina to each ovary to collect the eggs - around fifteen are usually gathered. The extras are frozen for use in future cycles.

Next , it's the man's turn. On the same day his partner's eggs are being collected he must produce a sperm sample. These two essential ingredients are then taken back to the lab and joined in a glass dish filled with a nutritive medium. Finally, if the embryo develops as hoped, two or three days after collection, it is transferred to the woman's uterus in a fairly simple medical procedure.

Throughout this month-long period, the couple will typically feel the emotional strain of science intruding into their intimacy. Their hopes will rise and fall with every part of the process, along with the woman's careering hormonal states.

One cycle of IVF costs between $5000 and $7500 and about 30 per cent of women who will eventually become pregnant through IVF will do so in the first cycle, the others will just start over again.

Medically, complications can arise through the hormone drugs administered during a cycle - they are very potent and there is an inherent risk of drug reactions from hyper-stimulation of the ovaries. Sadly, the number of peri-natal deaths with IVF pregnancies are double the national average - partly because multiple births are more common with IVF and often result in premature delivery.

Overall, IVF has a success rate of 15 to 20 per cent. For the others, IVF can mean a roller coaster of highest hopes and crushing disappointment.