The vast majority of people (approximately 95 per cent in parenting surveys) express the desire to have children at some point in their lives.¹ However, not all couples who desire pregnancy will achieve one spontaneously and some will require medical or lifestyle interventions to assist them towards their goal.

From 2007 data, it can be estimated that 3.1 per cent of babies born in Australia and 1.8 per cent of babies born in New Zealand are the result of assisted reproductive technology (ART) treatment.^2,3,4 The term ‘infertility’ is usually defined as the failure to conceive after one year of unprotected intercourse, however, it is a clinical continuum rather than an absolute or irreversible condition.

An international study by Boivin and colleagues in 2007⁵ found the prevalence of current infertility in ‘more developed’ countries to range from 3.5 per cent to 16.7 per cent, with a median figure of nine per cent in women aged 20 to 44 years. They also found the prevalence of lifetime infertility ranged from 6.6 per cent to 26.4 per cent, highlighting the fact that many couples’ delay in conception is not absolute. Interestingly, their findings relating to ‘less developed’ countries were very similar in numbers, although they speculated that the type of infertility and the mechanisms thereof may be quite different.⁵ For example, Cates et al in 1985 reported that most cases of infertility in Africa were due to treatable infection, a cause which is not common in the developed world. Conversely, the steady rise in age-related infertility is just not seen in less developed countries as it is in Australasia and other first world nations.^4,5,6

Closer to home, a study of Australian couples found that approximately one in six experience a delay of greater than 12 months to achieve a planned pregnancy during their reproductive life.⁷

It is commonly estimated that only half of couples that experience infertility seek medical treatment and those who do are frequently older, Caucasian, married women with higher levels of education and income. Less than half the couples who seek medical advice actually receive any specialist infertility treatment. These estimates appear to hold true both in countries that provide generous access to treatment such as Denmark and countries in which access is very restricted, like Gambia.^5,8

The European Society of Human Reproduction and Embryology (ESHRE) Capri Workshop Group has estimated that at least 1500 IVF cycles per million people are needed to meet demands.8 Denmark has been reported to have the highest IVF treatment ratios, with 1251 IVF cycles per 100,000 women of reproductive age, while Australia ranked third with 954 cycles per 100,000 women of reproductive age. New Zealand was amongst the lowest at 328 per 100,000, while the united Kingdom had 298 per 100,000 and interestingly, the United States had the lowest IVF treatment ratios with only 237 per 100,000 women of reproductive age. ⁹

A study in the uS found that both IVF utilisation and availability was positively correlated with the median state income, percentage of individuals 25 years of age or older with a bachelor’s degree, percentage of single persons, percentage of childless households, percentage urbanisation and presence of IVF insurance coverage.⁸ Unpublished data from Fertility Associates in New Zealand reveals similar trends to those found in the uS study. In New Zealand, education appears to be a better indicator of demand than income, however, both are positively correlated with uptake of fertility services. Individual motivation and GP referral behaviour may actually be better indicators suggesting that general community awareness regarding infertility issues still needs to be improved.

Looking again at local data, in 2007 there were 56,817 ART treatment cycles (including fresh and thawed cycles) in Australasia, 92 per cent from Australia and eight per cent from New Zealand. This reflects an increase of approximately 40,000 cycles per year since 1991. In Australia, there were 11.7 cycles per 1000 women of reproductive age (15 to 44 years old) compared to 4.9 cycles per 1000 women of reproductive age.⁴ In New Zealand, access to publicly funded ART is much more restricted than in Australia, with a maximum of two cycles of IVF funded providing that certain criteria are met, including a BMI restriction of 32 and age restriction of 39 years or less. Any treatment outside of this must be totally privately funded with costs generally upwards of NZ$9000. In contrast, Australia has an unrestricted approach to public funding of ART, with patients paying a part charge for each cycle with the Medicare Plus Safety Net picking up approximately 75 per cent of medical expenses once an individual’s or family’s threshold is reached (although the actual calculations are somewhat more complicated than this).

Based on the Australian and New Zealand Assisted Reproduction Database (ANZARD) 2007 data, the proportional representation of the four major groups of infertility treated by IVF or intrauterine insemination (IuI) in Australasia were: 33.6 per cent only female infertility; 27.7 per cent only male infertility; 21.8 per cent unexplained infertility; and 14.3 per cent combined male and female factors.⁴ The major change seen over the past 20 years has been a doubling in the proportion of unexplained infertility, halving the proportion of tubal infertility and a gradual increase in male and combined factors.¹⁰

It appears likely that there will be an increase in the incidence of infertility over the next decade. Contributing to this is the increasing obesity epidemic which is associated with anovulation (as well as increased miscarriage and poorer pregnancy outcomes), the falling mean sperm count and the increase in prevalence of sexually transmitted diseases in young women (although this does not seem to have made the dramatic increase in tubal infertility once predicted).

There has also been an obvious trend over the past 50 years throughout the western world for delaying childbirth. In New Zealand, for example, the average age at first birth has increased from 23.9 years in 1962 to 30.5 years in 2009.¹¹ The reasons for this are many and varied but may include financial pressures, the pressure of time spent in higher education and climbing the employment ladder to a point which is safe to take time away from work, and the frivolity and freedom that can be enjoyed by the relatively wealthy DINKYs (double income, no kids yet).¹² In contrast to this European view, however, in 2006 the National Fertility Study in Australia found that the first priorities for having children were a stable relationship and good income, while female career was further down the list. They also found that one in three women in their late twenties and early thirties were not in a stable relationship.⁷ A significant consequence of this delay in childbearing is an increase in unexplained infertility related to the natural decline in monthly fecundity with age from approximately 25 per cent at age 25 years to 16 per cent at 35 years and six per cent at 40 years.¹³ Unfortunately, there still appears to be some belief in the community that ART will negate the effects of age, however, IVF live birth rate declines with age in a similar way to natural fecundity.

At Fertility Associates, Auckland, the mean age at first private consultation has increased over the past ten years from 35 years to over 36.5 years. Over a 20-year timeframe, the average age at which a privately funded IVF cycle is initiated has risen from approximately 34.5 years to 38 years, with women aged 40 years or older now making up about one third of cycles compared to less than ten per cent in the late 1980s.¹³ The average age for all women undergoing ART in Australasia in 2007 was 35.7 years, with over one in five cycles undertaken by women aged 40 years and older. For women using their own oocytes, the average age was 35.5 years (0.5 years older than recorded in 2003), while the average age of women using donated oocytes was five years older at 40.5 years.⁴

Demographic data suggest that infertility is a significant issue throughout the world. It is important that infertility is considered a medical condition rather than a socially constructed need to ensure appropriate availability and delivery of treatment to those who require it. Ongoing community education regarding determinants of natural fertility will be important in minimising the impact of infertility into the future.

I would like to thank Dr Richard Fisher, Dr Freddie Graham and Alex Price of Fertility Associates for their contribution and editorial assistance with this article.