08/04/2014 04:51 BST | Updated 07/06/2014 06:59 BST

Is 50 Too Old to Have a Baby?

That's not a rhetorical question. I really want to know.

Last week, health ministers revealed that the number of women giving birth over the age of 50 had more than doubled in the past five years. On average three babies are now being born to women in their 50s every week.

Within days of this announcement, a twitter storm erupted between the singer Jamelia and the actress Tina Malone (of Shameless). Jamelia, appearing on the TV show Loose Women, was asked what she thought about older motherhood and said that she thought 50 was far too old to have a baby. Malone, aged 51, who was clearly watching the show at home with her new born tweeted she was 'furious' at Jamelia's comments claiming that she could stay up partying in a club until 5am and was far better in the kitchen and the bedroom than when she was younger. I'm not sure these credentials necessarily make you a better mother but you get her point.

At the age of 43 - still baby-less yet still baby-hopeful - I feel like I should have a strong opinion on the subject but I'm genuinely confused. Like any liberal feminist (with a small 'l' and a small 'f'), I defend a woman's right to choose what she wants to do with her life and her body. If something is biologically possible and legal then why not? Moreover, with life expectancy increasing and society still frowning on teenage pregnancy, it makes a lot of sense. Girls are actively encouraged to get educated, pursue their careers and try out a few prospective partners before settling down. Well, I was.

Of all people Tina Malone certainly knows the relative pros and cons. She gave birth to her first daughter aged 17 and then to her second 33 years later aged 50. In an article in Fertility Road magazine recently she said the only advantage of having a baby younger is that youth blinkers you to the all the things that can go wrong.

But there is another side in coming late to motherhood that often isn't being said. The vast majority of women giving birth over 50, indeed most women over 45, are doing so with donor eggs of a younger (often unknown) woman. Contrary to what Hollywood stars will have you believe, giving birth to your own biological baby once you've established your 'A-list' credentials is not something you can generally do without assistance. Of course there will always be the 'Cherie Blair factor' but such exceptions are few and far between.

Following the publication of my book, The Pursuit of Motherhood, I recently spoke at an event with the Consultant Obstetrician Professor Susan Bewley. Susan is well known within the fertility world for flagging up the dangers of late motherhood. She shocked me by saying that there's actually an evolutionary reason that women generally menopause around the age of 50 and that's to make sure they're not in danger of getting pregnant themselves when their daughters are becoming mothers so they're in a position to support them.

If you do the maths this means that in evolutionary terms the recommended age for a woman to have a baby is around 25. But when nowadays lots of young people can't even afford to leave home at 25 (or at the very least are living in a room in a shared house) is having a baby in your mid twenties really a sensible or indeed affordable thing? Moreover, most people I know who have had children younger have to rely heavily on the support of their parents and that's not out of any evolutionary choice but because they can't afford the cost of childcare. It's a reality of the modern world that many grandparents, aged 50 and above, are finding themselves parenting again. And if that's the case, is 50 really too old to have a baby?