'Superfetation Twins' Conceived 3 Weeks Apart Born at Same Time: 'It Was Quite Scary,' Says Mom

"What came after getting pregnant was just such incredible hard work," Rebecca Roberts told Good Morning America of her "super twins"

Rebecca Roberts twins
Photo: @roberts.supertwins/Rebecca Roberts

A new mom in England is breathing a sigh of relief after a harrowing pregnancy allowed her to give birth to two siblings who were conceived weeks apart.

The phenomenon, known as superfetation, occurred when Rebecca Roberts was already pregnant with one baby — son Noah — and then got the shock of a lifetime when, during her 12-week ultrasound, they found a second baby that hadn't been there before.

"My initial reaction was, 'How had I missed the second twin?' " Roberts' OBGYN, Dr. David Walker at Royal United Hospital in Bath, told Good Morning America. "And following this [I] was slightly relieved that it was not my mistake but a quite extraordinary pregnancy."

Superfetation occurs when an egg is released from a woman's ovary after she may be pregnant already, and implants alongside the first embryo in the uterus some time later.

"It was really, really shocking to be told there were two babies instead of one," Roberts, 39, told GMA. "Then they told me there was a three-week size difference between the two babies that the doctors couldn't understand."

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Roberts, who lives in the English town of Wiltshire, was told by her medical team that her younger baby — daughter Rosalie — may not survive.

But when her mother gave birth at 33 weeks gestation with Noah, Rosalie was delivered at 30 weeks before spending three months in the neonatal intensive care unit. Roberts was induced because her daughter had stopped growing, due to an issue with her umbilical cord. Her placenta also "never really grew properly," according to her mother.

"With twins it's scary already and then because of my age and the fact that they were conceived at different points, and then we were told that all the odds were against Rosalie," Roberts told GMA of her baby girl, who was born weighing 2 lbs., 7 oz., while her brother weighed 4 lbs., 10 oz.

"What came after getting pregnant was just such incredible hard work," she also said. "It wasn't all happy and rainbows like you expect a pregnancy to be. It was quite scary."

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Rosalie left the hospital to come home just after Christmas, and Roberts said that she's already catching up to Noah in terms of her growth.

Their bond is something special, too. "When we lay them down next to each other, it's like they instantly know and they reach out and touch each other's faces and it's just the most beautiful thing," she said. "Twins have an amazing bond anyways but the story between these two, when they're old enough to find out, they'll feel even more special."

Roberts said she and husband Rhys "were trying for ages to" conceive with no luck before the twins, and that they were "worth waiting for."

"They're my super twins," the proud mother of two told GMA. "Every day I look at them and think, 'Wow, I'm so lucky.' "

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