Pregnant Woman Pregnant Again? Maybe Not
Arkansas Woman's Superfetation Pregnancy Is Possible but Unlikely, Expert Says
Sept. 25, 2009 -- The media have been buzzing with reports of a pregnant
woman in Arkansas getting pregnant again, with her babies conceived two and a
half weeks apart.
Her case might be a rare example of "superfetation," in which a pregnant
woman ovulates and winds up with a second pregnancy.
But the key word there is "might." It's not certain that Todd and Julia
Grovenburg of Fort Smith, Ark., have a superfetation pregnancy.
The Arkansas TV station that interviewed the Grovenburgs posted a statement
from Julia Grovenburg's doctor, who confirms that Grovenburg is pregnant with
twins and "there appears to be a discordant growth pattern, possibly due to
Her doctor, identified as M. Muyalert, MD, says that superfetation is "an
unusual and rare condition, but the possibility is real."
But Muyalert cannot confirm superfetation, stating only that there is a
"suspicion of superfetation" in the Grovenburgs' case.
Jeffrey Kuller, MD, professor of obstetrics and gynecology at Duke
University Medical Center, tells WebMD that based on the media reports he's
seen, he's "skeptical" that the Grovenburg pregnancy is a case of
"It's possible that this has occurred, but it's certainly not for certain,"
Kuller says obstetrical textbooks mention a handful of reported cases of
superfetation, but it's "extremely uncommon" and is biologically "unlikely,"
although not implausible.
"The only way it can happen is if someone ovulates again after they get
pregnant. But usually, the hormonal state of pregnancy is not conducive to
someone ovulating again," Kuller says.
"We occasionally see a patient like this, where you'll see a discrepancy
between the twin weights and growth, and oftentimes, the more likely
explanation is just that one is lagging in growth or one has a problem, like a
chromosomal abnormality, that makes it smaller than the other one," Kuller
It's possible that the Grovenburgs' second baby wasn't discovered earlier
during the pregnancy, notes Kuller, who says he had a patient with a suspected
case of superfetation several years ago but no certain cases of
One of the challenges of a superfetation pregnancy would be timing the
delivery of the babies, Kuller says.
"If you truly believed it was a superfetation pregnancy, you would have to
decide the best time for both of the babies to be delivered," he says, noting
that twins are usually delivered at 38 weeks.
But what if one baby was conceived a couple of weeks ahead of the other one?
Then it's a matter of finding a compromise delivery date that would be best for
both babies, "so that one didn't go post-term and the other preterm," Kuller
"But again," Kuller says, "this would be such a rare event that there would
be no way to say, based on the last 10 we did ... or based on the literature,
this is how you should follow such a pregnancy."
In the couple's interview with Arkansas TV station KFSM, Julie Grovenburg
says the babies, Jillian and Hudson, appear "perfectly healthy" and are due in
early December. She says that to prove superfetation "without a shadow of a
doubt, would have to be something that was done after the babies are born."
But doctors may never be able to tell the Grovenburgs for sure if their
babies came from a superfetation pregnancy.
"I don't think there would be a definitive way to do that," Kuller says. "I
think it would still be speculative."