One in six Australian couples experiences fertility problems and according to the Department of Health there is an increasing occurrence of infertility in Australia.
But why are the fertility rates decreasing? Are the causes scientific, social or a bit of both?
Dr Michelle Wellman, a Fertility Specialist and Surgical Gynaecologist at Fertility SA, says while fertility struggles have been experienced in every generation, fertility rates have been declining due to a range of social and medical factors.
“Infertility in Australia, and the majority of the western world, starts with social factors, which can then lead to health-related and biological factors,” Dr Wellman said
“We certainly don’t know all the reasons for the declining fertility rate, but we do see age, lifestyle and the environment all having a significant impact.”
We are having children later
According to the 2015 Australian Institute of Health and Welfare report, babies are increasingly likely to be born to older mums.
In 2015, the average age of all women who had babies was 30.3 years, up from 29.7 a decade earlier. In addition there has been a slide in women under 25 giving birth, and an increase in women over 35 giving birth.
Over the same 10-year period, the average age of first-time mums also increased by almost a year, to 28.9 years.
“This is a complex, societal trend, and not as straight forward as women simply choosing to have children later as is often reported in the media,” Dr Wellman said.
Both men and women are staying in formal education for longer periods, are more burdened by debt, are entering marriage and partnerships later, and in turn are starting families later too.
“While some women choose to have children later, in my experience it’s often not the women’s choice at all, but rather a societal expectation that women now can, or should, have children later,” Dr Wellman said.
“There has been a change in society’s expectations of women, and a lack of support for women to become mothers earlier in life.
“Male partners can often delay the decision to have children because there’s a lack of urgency for them – I often see women staying in relationships with men who aren’t ready for children, and may not be aware of the difficulties they will face when they finally are ready.”
While the age at which people are having children is increasing, the biology of conception hasn’t changed, and the chances of conception for women decrease quickly after 35.
By the age of 43 the chances of a woman conceiving with her own eggs is about 5%, and by 45 that chance decreases to 1%.
Dr Wellman emphasises that while IVF is an excellent option for those who are unable to conceive naturally, it cannot overcome the problem of having older eggs.
“Women’s eggs sit in a very fragile state of division within the ovary, and when the egg performs the last part of this division after fertilisation the genetic material may not divide evenly,” Dr Wellman said.
“This means that older eggs of poorer quality are less likely to form a healthy embryo, and as a result, will be less likely to implant in the uterus.”
Endometriosis or fibroids may become more of a problem as a woman gets older too, and will also interfere with fertility.
The environment is decreasing fertility
But it’s not all about women, Dr Wellman says that male fertility deteriorates later in life too, with older men less likely to conceive, and some studies showing that the quality of sperm after 40 can contribute to genetic mutations.
A recently released 38-year study also showed that sperm count has declined significantly since the 1970s, which suggests both environmental and lifestyle factors.
“We are also becoming increasingly aware of other environmental factors such as men using laptops, overheating and environmental factors including plastics, but these are harder to quantify and more research is needed to fully understand their impact.”
Lifestyle factors are having an impact
In addition to age and environmental factors, the western lifestyle is also reducing the general fertility rates.
Smoking and being either over-weight or significantly under-weight are known to have the biggest impact on fertility and the chances of conception.
“Poor nutrition, increased BMI, smoking and excessive alcohol and drug use are major factors contributing to infertility.
“But these factors are controllable, and we see many patients every year, who are able to conceive with very little assistance once they have made lifestyle modifications.”
Taking the right action
Although fertility rates are decreasing, there are also more choices available for people experiencing fertility problems.
“My advice for both people who are concerned about getting pregnant, and their GP’s who are working with them, is to have a conversation with a professional sooner rather than later.
“Focus on being as healthy as possible, but also don’t take too long to seek help.
We see a lot of people who wait too long to see us, and when it comes to conception, timing is everything.”
