Surprise conception: Woman conceives second child while carrying first

At first, baby Noah was all alone, growing beatifically in his mother’s womb.

Noah’s first close-ups, taken by ultrasound at seven and 10 weeks into the pregnancy, showed 39-year-old mom Rebecca Roberts and 43-year-old dad Rhys Weaver the baby they had tried for more than a year to conceive.

Then, at three months into the pregnancy, Noah suddenly had company.

An ultrasound taken at week 12 showed that Noah had an unexpected little sister – fraternal twin Rosalie.

“I got pregnant whilst I was already pregnant, which was absolutely crazy … because that’s not supposed to happen,” Rebecca said.

Baby Noah was joined in utero by fraternal twin Rosalie some three weeks after Noah's conception. 

Courtesy Rebecca Roberts

Called a superfetation, getting pregnant while already carrying a baby is so rare that one 2008 study found fewer than 10 recorded cases in the world.

Doctors told the couple the babies were actually conceived about three weeks apart, Rebecca said.

“They realized that the baby was growing at a consistent rate of three weeks behind the first one, and it was then that they said to me, they think this is a superfetation pregnancy,” she said.

“I couldn’t believe it had happened to me,” Rebecca added with a laugh. “But it did – it’s lovely. It’s like winning the lottery.”

Dad felt the same: “I was elated to be having one child, but even more so for twins. The job is done in one go! And then Rebecca did some research, and we realized how unique and how lucky we were.”