Mum, 44, pregnant with son’s ‘quadruplet’ brother who will be born 12 years apart

If you're a fan of a brain-teaser or can't resist cracking a riddle, we've got a hell of head-scratcher for you...

A mother in Canada is currently pregnant with her son's 'quadruplet' brother, 12 years after giving birth to him.

Tanis Larson, 44, is already a mother-of-four and has been using her social media platforms as a means of 'challenging the narrative of pregnancy over 35'.

And taking to TikTok this week, the internet star revealed that she's expecting her sixth child, who is actually a 'quadruplet' of her three already-born sons.

'But, how?', I hear you ask. Well, it turns out there a rather simple explanation.

Back in 2010, Tanis opted to freeze her eggs in the hope of one day using IVF to conceive a child.

Since then, she has welcomed three of her sons using her frozen embryos, meaning they're all from the same 2010 cycle.

The online star welcomed her first child aged 32, her second at 35 and her third aged 38.

Tanis went on to welcome her fourth child aged 40, and her fifth aged 42.

TikTok/@tanislarson

And despite having spent a decade - give or take - pregnant, last year, she opted to try for her sixth child, falling back onto her frozen embryos 14 years later.

Sharing a black and white snap of a positive pregnancy test on the video-sharing app, she wrote: "When you decide to use your 13-year-old frozen growing embryos at 44-years-old and are now expecting your son's 'quadruplet brother' due May 2024.

"All four boys are from the same cycle in 2010."

And if you're STILL struggling to get your head around Tanis' miracle family situation, believe me, you're not the only one.

It looks as though a handful of her online followers are just as blown away by the news, with making taking the the video's comment section to recall their own unconventional pregnancies.

Instagram/@tanislarson

"Transfer twins we call it - but love this even more !" one fan gushed.

Another explained: "My mom had my twin brother and my’s “triplet” at age 45, after being frozen for 13 years. At the time in 2005, it was the longest an embryo had been frozen to successful pregnancy!"

"IVF triplets 12 yr old and 4 yr old twins. Love to hear others successes," a third noted.

Another went on "My 2 boys were both frozen embryos at the same time, so crazy to think they actually came into existence together".