Woman Gets Pregnant While Already Pregnant, Gives Birth To Twins Conceived 3 Weeks Apart

Rebecca Roberts and her partner struggled with infertility for more than a year, so when they got a positive result with an at-home pregnancy test, they were overjoyed.

But the news didn’t feel real until the first ultrasound appointment, when the couple saw their baby on a sonogram screen and listened to the calming cadence of a steady heartbeat.

“I remember walking away from the very first scan so happy,” said Roberts, 39, who lives in Wiltshire, England.

But her excitement abruptly shifted to shock five weeks later at the 12-week ultrasound appointment, when the sonographer spotted something astonishing: It appeared as though Roberts was suddenly carrying two babies — one of which was considerably less-developed than the other. The room fell silent.

“I thought something awful had happened,” Roberts said. “The sonographer looked at me and was like, ‘do you know you’re expecting twins?’ ”

But this wasn’t a typical set of twins, Roberts learned. Her pregnancy was diagnosed as superfetation, a rare condition in which a woman who is already pregnant conceives another baby.

“We were concerned because the second twin was much smaller. It was only by regularly scanning and seeing that the rate of growth was consistently three weeks behind that we realized it was superfetation,” he explained.

Ordinarily, hormonal and physical changes during pregnancy prevent another conception from occurring. That wasn’t the case for Roberts.

“Instead of stopping ovulation, she released another egg about three or four weeks after the first one, and the egg somehow miraculously managed to fertilize and implant in her uterus,” Walker said.

Although Roberts was taking a fertility drug to stimulate ovulation, Walker said he’s “not convinced” the medication — which can increase the chances of having multiples — is what caused the superfetation.

“She didn’t release two eggs at the same time, which is what the medication normally does,” Walker said. “But we have no way of proving it one way or another.”

Given the rarity of the condition, coupled with Roberts’s age and the common risks associated with carrying twins, the pregnancy brought some challenges, particularly during the third trimester. The couple was told the younger baby might not survive.


“Anything that can go wrong with a pregnancy is more common with twin pregnancies. But with a three-week difference, you don’t want to compromise the smaller twin by delivering too early. You have to keep a really close eye,” Walker said. “The delivery was crucial in this case.”

Roberts knew preterm labor was likely, so ensuring the smaller baby was far along enough before birth, “was a really massive worry for us,” she said.

At just over 33 weeks into the pregnancy, the smaller fetus’s umbilical cord wasn’t functioning normally, which started to impact the baby’s growth. Doctors decided it was time to deliver.

Although Roberts’s children technically had different due dates, she had a Caesarean section and gave birth to both babies on Sept. 17. Noah came first, weighing 4 pounds, 10 ounces. Two minutes later, his younger sister, Rosalie, arrived, weighing 2 pounds, 7 ounces.

“We got to see both of them as soon as they were born,” Roberts said. “It was absolutely beautiful.”


“One of the best feelings I’ve ever had,” Weaver said.

The family’s initial bonding time was short-lived, as both babies were whisked away to the neonatal intensive care unit. Noah remained in the hospital for just over three weeks, while Rosalie stayed for 95 days.

Rosalie is still much smaller and less advanced than her brother, “but she’s catching up to him fast,” said Weaver, a mortgage adviser.

Regardless of their developmental differences, though, their twin bond is unmistakable, the couple said.

“When we lay them down next to each other on their play mat, they look at each other, reach out and touch each other, and talk to each other as well,” Roberts said. “It is so beautiful to watch.”

“Miracles can happen, and my children are proof of that.”

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