Shelley Bridgeman: The risks of delaying motherhood

There are so many things to consider when it comes to having a baby. Photo / Thinkstock

A fertility expert recently appeared on TVNZ's Breakfast advising women to plan their reproductive lives. Dr Mary Birdsall echoed a UK reproductive biologist's warning that to avoid facing needless fertility issues women should plan to have their children before the age of 35.

"Particularly if you want more than one child, you really need to get on with it," said Birdsall, adding that despite advances in fertility treatment "what we can't do is make older eggs into younger eggs". She recommended women take an AMH blood-test in their 20s to determine when menopause will occur; this enables them to "extrapolate how much reproductive time you've got".

Egg freezing is also an option. This is a process in which a woman's eggs are harvested when she is young, and stored so they can be used to create an embryo at a later date when the quality of the woman's retained eggs will have diminished.

As revealed in Kate Garraway: I wish I'd had my babies younger, the British broadcaster is "backing a campaign to encourage women to think about having children at a younger age - before leaving it too late". Aware that she's probably now too old to have a third child, Garraway says, "my fertility door is slamming shut."

It's all very well to talk of planning your reproductive life but sometimes circumstances get in the way. Firstly, there's that small yet crucial matter of needing to find a suitable partner. Secondly, many people wish to become established in their careers and financially secure before starting a family.

And thirdly, not all women are programmed to want children from the outset. In my 20s and early 30s, I had no intention of having kids. It wasn't until I was 36 that I seriously even contemplated the idea. Two miscarriages later, I considered myself lucky to have finally had my daughter at the ripe old age of 38.

Read: Blogger Rebecca Kamm admits 'I'm terrified of childbirth'

Having a baby at this age (or, in fact, at any age beyond 30) is nothing short of "disgusting" according to someone who commented at How old is too old to have a baby?. Goodness knows what this person would make of the women featured in Older Celebrity Moms: Halle Berry And Other Stars Who've Had Children After 40. The list included: Mariah Carey, Tina Fey, Salma Hayek, Uma Thurman, Geena Davis, Julianne Moore, Meryl Streep, Nicole Kidman, Celine Dion and Jane Seymour.

While these high profile women are doing their bit to normalise the notion of having babies over the age of 40, it should be noted that these examples are the exception rather than the rule. Fertility experts around the world have long been sending the message that women delay childbirth at their peril.

As the Advanced Fertility Center of Chicago explains, the "real issue is egg quantity and quality - which translates into embryo quality after fertilization". In short: older eggs have a greater risk of chromosomal abnormalities.

Yet with this knowledge surely comes power - the power to think ahead and attempt to thwart the natural decline of our fertility. If I was a 20-something who wanted to keep my options open I'd certainly consider storing my youthful eggs just in case.

According to Fertility Associates, just 5000 babies worldwide have been born from frozen eggs (compared with one-million or more from frozen embryos). I'm picking that number is set to soar as young career women see the benefits of putting their eggs on ice.

Were you an older first-time mother? What factors led to you delay starting a family? If you're a younger woman, would you consider having your eggs frozen?