Twins 'possibly conceived a week apart'

Craig Robinson

FOR Alison Jennings and her husband Stephen, the arrival of their twin girls may have been even more extraordinary than most.

It is possible five-month-olds Grace and Lana were conceived about a week apart from one another.

The incredibly rare phenomenon is known as superfetation - the formation of a foetus while another foetus is already present in the uterus.

The couple, of Titus Way, Colchester, who also have a four-year-old son called Nathan, first discovered this was possible during a routine 12-week scan.

A sonographer at Colchester General Hospital found that one of the babies was a lot smaller than the other and suggested that they could have been conceived separately from two different eggs four or five days apart.

Mrs Jennings, 39, said: “It's not set in stone and I can't say if she's right or wrong but that's what she told me.

“Grace was the smaller of the two and the sonographer said she was so tiny that she couldn't do the scan. As a result I had to wait 10 days until we could have another look.

“Obviously this is extremely rare because when you become pregnant your body stops producing eggs.

“It wasn't something I'd heard of before but I've since looked on the internet and it can happen. When Grace and Lana were born there were two different placentas.”

After 37 weeks of the pregnancy Mrs Jennings caught pneumonia and was rushed into hospital by her husband because she had trouble breathing in the early hours of December 7.

Within three-and-a-half hours doctors decided the babies should be delivered by emergency Caesarean.

Grace - who was born first and weighed 5lbs5oz - and Lana - who weighed 6lbs9oz - had to spend 10 days in the special baby care unit.

“Because I was still very ill I wasn't able to look after them myself but I went down on the day I gave birth,” Mrs Jennings, who also had to stay in hospital, said. “It was quite a traumatic experience.

“I'm not 100% sure how I caught pneumonia but the pregnancy did wear me out.”

Mrs Jennings said the three of them were allowed home just before Christmas and was full of praise for the hospital staff.

“They were amazing,” she said. “I can't praise them enough. The girls are both doing wonderfully. They have two different temperaments - Grace is very laid back and Lana is a bit of a prima donna and wants to be number one! They are very good and seem very happy.”

A spokesman for the Royal College of Obstetricians and Gynaecologists said superfetation was extremely rare.

“It is so unlikely that we don't even have any statistics about how rare it is,” he said. “There have been a few cases reported but it's very unlikely that the babies were conceived a week apart. Usually when it happens a woman has released two eggs at the same time and had sex within a short space of time - say 24 hours.

“What's more likely is that the babies just developed differently with one smaller than the other, which is perfectly feasible.”

Superfetation

A term used to describe the formation of a foetus while another foetus is already present in the uterus.

It occurs when eggs from two separate menstrual cycles are released, as opposed to normal dizygotic twins where multiple ova are expelled in a single cycle.

Although common in animals it is rare in humans but can result in a twin or multiple pregnancy where the foetuses display a marked difference in gestational development.