A woman who was told having children "wasn’t a possibility" for her fell pregnant naturally 10 days before undergoing IVF – and ended up with 'triplets'."

Shelby Stewart, 31, found out she would be unable to have children aged 19 – after undergoing treatment for non-Hodgkin's lymphoma, a type of cancer, aged 15.

Shelby was told she would likely go into menopause by 26 due to the treatment but after meeting her husband, Chase, 36, who works in sales, the couple decided to try for a baby.

They tried for a year naturally before undergoing intrauterine insemination (IUI) - a fertility treatment that involves directly inserting sperm into the womb.

And after two attempts they welcomed their "miracle" daughter Bennett, now five, in June 2018."

With a "small window", they tried again six months later and after five failed IUI attempts and three miscarriages through IVF they found out they were pregnant in October 2020 – after having two eggs implanted during their fourth round of treatment."

But to their surprise, they were told they were expecting triplets – and presumed one embryo had split meaning they were having two identical girls and a boy.

Shelby carried the triplets to 35 weeks and gave birth to their girls Etta, Margot, and their son, Garner, now two, on May 19, 2021, at 8am – each weighing 4lbs 8oz, 4lbs 14oz and 3lbs 14oz respectively.

The parents realised their ‘identical girls’ didn’t look the same and following DNA testing Shelby discovered Margot had been conceived naturally 10 days before the egg transfer in March 2022.

Shelby, a stay-at-home-mum, from Vineyard, Utah, US, said: "This shouldn’t have happened, but here we are with three healthy babies."

"It’s completely insane."

"My life looks nothing like I imagined it."

"The triplets have a bond like nothing I’ve experienced."

Shelby underwent chemotherapy, radiotherapy and open chest surgery to remove her tumour aged 15 but didn’t discover the treatment had affected her fertility until she was 19.

She said: "I went to ask about having babies."

"They said that’s not really going to be a possibility."

"They said I would probably go into the menopause by the time I was 26."

Shelby looked into egg retrieval at the time but was told her hormone levels were too low, so she "shelved" the idea of having children."

After she met Chase in 2014, the pair tied the knot in 2015 and started trying for a family straight away - on the off chance.

Shelby said: "He said ‘we’ll figure out a way, we’ll be parents."

After a year of trying, they visited a fertility clinic and decided to give IUI a shot.

Unexpectantly, they fell pregnant on their second go and gave birth to Bennett in June 2018, weighing 6lbs 8oz.

Shelby said: "I was so happy."

"I wasn't supposed to have this baby, but she was perfect."

"I felt so empowered having her."

Chase and Shelby wanted to try again to complete their family – and give Bennett a sibling.

She said: "We thought if we’re going to give her a sibling my window is probably very small."

When Bennett was six months old, Shelby started IUI again but after five failed attempts they were recommended IVF instead.

They were devastated after their three rounds of IVF ended in three miscarriages.

Shelby said: "We were back at square one."

"At that point we were completely out of eggs."

The couple decided to "keep going" and went for another egg retrieval in July 2020, and ended up with six high quality eggs."

To give them the best shot, they decided to have two of the strongest embryos implanted in October 2020.

The couple were originally told it had been a success, but when their bloodwork came back Shelby was told her HGC levels were not doubling.

Shelby said: "I was beside myself."

"I thought – I’m having a fourth miscarriage."

But they discovered it had been an error in the bloodwork and following an ultrasound they found out they were expecting triplets.

Shelby said: "We were all looking at the screen all quietly."

"There were three perfect little sacs all together."

"The sonographer said ‘how many embryos did you put in there?’"

"We said two and she ‘well, there are three’."

The couple were told an embryo must have split early meaning they were having two identical girls and a boy.

After getting their heads around expecting triplets, Shelby was determined to carry them for as long as she could.

She went into pre-term labour in April 2021 but managed to hold them in for four weeks.

She said: "Baby A – Garner- turned transverse so he was holding his sisters in."

"I was in so much pain – contracting every three minutes."

Shelby managed to walk into her c-section and gave birth to Garner, Etta and Margot on May 19, 2021, at Intermountain Medical Center, Murray, Utah, US.

The parents noticed right away that Margot and Etta didn’t look identical.

She said: "I remember when they held Margot up to me, she had a lot of hair."

"Etta didn’t have much."

"Their head shape looked very different."

Shelby didn’t think anything more of it after being re-admitted to hospital for heart failure from the delivery but decided to look into it when she and the babies were all home.

She said: "People were like: 'Your girls don’t look anything alike.'"

"It caused me a lot of anxiety."

Chase had filmed the egg transfer, so the couple were able to check that only two embryos had been implanted.

They decided to get them DNA tested – which confirmed Margot and Etta were not identical.

Shelby consulted a genetic counsellor and was told she may have got naturally pregnant while undergoing IVF - and she was determined to find out which baby was the spontaneous baby.

She was able to check the genetics from the fertility clinic and found a profile that matched Etta – revealing Margot as their spontaneous baby.

Shelby said: "What must have happened is we were intimate 10 days before the egg transfer."

"Sperm can last for five to six days so there must have still been a follicle on day five which has fertilised but didn’t implant until the day of the transfer."

"The genetics counsellor said the chances of this happening are one-in-a-million."

"It’s crazy."

Shelby said Margot is her "craziest baby", Etta is "so funny" and the "snuggliest baby" whereas Garner is a "boy through and through" but with the "gentlest disposition"."

Shelby said: "They are all so incredibly unique but love each other so much."

"They don’t like to be away from each other."

Life as a family-of-six has been "adjustment" for the parents – who go were going through 672 ounces of formula and 150 nappies a week in the first few months."

Shelby said: "The first year was just survival."

"I knew it would be hard to have kids, but I didn’t imagine it being that hard."

"But we ended up with four kids."