"You can hear that they are tortured in their decision because they are doing it for their families. They often say, 'Financially we can't do it. I would lose my job, we'd have to get a bigger car. If this happens I can't look after the first three children properly.' It's real life and it's a very common situation."
Online forums and parenting Facebook groups are littered with anonymous accounts from middle-aged mothers fraught with their decision.
"So I have very unexpectedly found myself pregnant at the age of almost 45," wrote an anonymous Sydney woman on a closed parenting Facebook group.
"My husband and I already have two children — 11 and 13. We hadn't planned this at all and didn't even think it was possible," she said.
"Another child would have a significant impact on our careers, our finances, our family dynamic and there is the also unknown question of my husband's future health.
"I've already booked in for a termination and I guess all I'm asking for is some reassurance I'm making the right decision."
President of Reproductive Choice Australia, Jenny Elak, said the stereotype is different to the reality.
"It's often portrayed as young women (who) don't take enough responsibility, when in reality, no contraception is 100 per cent effective, even when both partners are being very careful," Ms Elak told news.com.au.
"Unintended pregnancies can happen to anyone, regardless of how careful you are and it's really important that we don't judge people. Every woman will be unique and her desire to have children or not is up to her. It's important to not make generalisations and not stereotype and make assumptions," she said.
Dr Melville says it's common for women to fall pregnant just after they've given birth, because contraception is often the last thing on their minds while juggling a newborn.
"When you speak to a new mother on day one and you say, 'Are you thinking about contraception?' and they say, 'Are you ridiculous? I'm never having sex again.' It's not a priority. There is so much going on that thinking about contraception and sex is not at the front of their mind," Dr Melville said.
The World Health Organisation recommends the gap between children should be 24 months.
"Under 12 months, there is lots of research showing there are poorer outcomes for babies and mums," Dr Melville said.
Many women in their 40s also fall pregnant because they incorrectly believe reduced fertility means they no longer need contraception.
"Sometimes when women are moving towards menopause, they might be told they are no longer fertile and therefore no longer need contraception, but that's not always the case," said Jenny Elak.
"Fertility can be quite erratic for a number of years before women stop ovulating completely and it's always different for every individual," Ms Elak said.
Dr Melville says anyone under 55 needs to remain on contraception if they do not want any more children.
"If your last period happened under the age of 50, you need to wait two years before you stop contraception," Dr Melville said.
"Somebody aged 51 who is having the odd period ... your period is massively reduced but it just takes one fighter sperm and a little egg to make a baby.
"It's not uncommon. I speak to women in their early 40s and they said 'I just didn't know at this stage of my life that I could still get pregnant'."
It's also important to note that many women may not be having consensual sex.
"There are quite high rates of sexual violence in Australia," Ms Elak said. "Often women are having unprotected sex when they don't want it, so they're not prepared for it."
