By Stephanie Jacob
A woman in Arkansas is pregnant with two
babies -- but not twins. When she went in for a routine ultrasound,
doctors discovered that Julia Grovenburg had a second fetus, a male,
growing alongside her first, a female, according to ABC News.
This extremely rare medical condition is known as superfetation and
occurs when a woman conceives a second child when she's already
pregnant. “When the woman had her ultrasound initially, they saw one
sack, one baby developing, and that baby had a certain gestational age;
then they noticed a second heartbeat in a child that was much, much
younger developmentally,” Karen Boyle, M.D., of the Greater Baltimore
Medical Center, told ABC News.
Watch to learn more information about the double pregnancy. Story continues below the video.
In Grovenburg’s case, the babies were reportedly conceived two and a half to three weeks apart and have different due dates (one in 2009 and one in 2010). Though it is unlikely that they won’t be born on the same day, Boyle told ABC News they are not technically considered twins.
Identical twins are defined as one fertilized egg that splits in two. Fraternal twins begin as two separate eggs that are ovulated simultaneously and then fertilized at the same time, Boyle said. In Grovenburg’s case, one egg was ovulated and then fertilized. Two and half to three weeks later, the same thing happened again, only to a second egg.
The risk with superfetation, Boyle said, is that the second baby is often born prematurely, which can increase its chances of having lung development problems. However, because the two babies are just a few weeks apart, there’s a decreased risk that the second baby conceived, a boy already named Hudson, will develop additional problems. The first baby, a girl, has been named Jillian.
Boyle said she was able to find only 10 reported cases of superfetation. While Grovenburg’s case appears to be superfetation, her obstetrician, Dr. Michael Muylaert told Arkansas’ KFSM-TV that “it can only be confirmed after delivery by chromosomal and metabolic studies on the baby.”
