When she’s waiting, there’s a guess that she can’t get pregnant again. I mean, you’re already on top: you can’t get more pregnant than that, can you?
Well, actually, it might not be as simple as that.
That’s what Kate Hill, Brisbane mom, discovered. Their two daughters, Charlotte and Olivia, were conceived ten days apart.
When Kate discovered what had happened, which she had conceived twice in the same month, she did what any of us would do and began to google frantically.
“We were shocked, scared and excited at the same time,” Kate told Us Weekly.
“Throughout our pregnancy, we were constantly concerned about her growth and how much smaller the baby number 2 would be.”
In Kate’s case, she explained that she had become pregnant and that her body had “spontaneously released another egg, giving the embryos different gestational ages.”
And in case you think that this kind of thing can only happen if you have sex after you’re pregnant, think again.
“What makes this case even rarer is that my husband and I only had sex once (in the possible period of conceiving girls): their sperm stayed alive for 10 days to fertilize the second released egg,” Kate said.
She’s not the only …
In one perhaps even more unusual case, Jessica Allen was carrying a baby as a surrogate for a Chinese couple when she became pregnant with her own child.
Jessica and her partner were using condoms and didn’t think for a moment that they might get pregnant while Jessica was already waiting.
But that’s exactly what happened. One DNA test after the birth of the babies concluded that one baby was a genetic combination for the Chinese couple, while the other matched her and her partner.
What is this sorcery?
Getting pregnant when you’re already having a baby is known as superfetation.
According to MedicineNet, superfetation is “an extremely rare situation in which a pregnant woman becomes pregnant for the second time with another (younger) fetus.”
In other words, a second egg is fertilized and implanted in a uterus that already contains another pregnancy.
One of the differences between “regular” twins is that in a twin pregnancy, both babies have the same due date and have the same gestational age.
But in superfetation, babies have different ages and expiration dates.
MedicineNet goes on to say, “Superfetation may occur in some animals, but it is so rare in humans that fewer than ten cases have been reported in the medical literature.”
Honestly, what the hell …?
The obstetrician, gynecologist, and fertility specialist, Dr. Alex Polyakov, is quite skeptical about superfetation.
“When a woman is pregnant, there are several barriers to getting pregnant with another baby,” she says.
These include changes in hormone levels and thickening of the lining of the uterus.
In fact, he says, most of the cases that have been reported as “superfetation” can be attributed to twins that grow at mismatched rates (known as “discordant growth”).
“In addition, very occasionally only one baby is detected on the initial pregnancy appointment scan, but then, on a subsequent scan, another baby is discovered,” says Dr. Polyakov.
He explains that this happens “not so infrequently” since the first scan is usually performed very early in pregnancy, about 6 to 7 weeks, meaning that the scan expert may “lose” to see a second gestational sac.
That second sac is detected later on the 12-week scan.
Dr. Polyakov says the most recent reports of superfetation often involve some form of fertility treatment, either ovulation induction or IVF.
“Sometimes superfetation is supposed to occur when only one embryo is transferred, and yet there is a twin pregnancy with non-identical twins.”
“This can usually be explained by a natural pregnancy that takes place along with one of IVF”.
The bottom line
“You can never be completely 100% sure that something never happens,” says Dr. Polyakov.
“But in humans, superfetation must be an extremely rare event.”
So, if you’re already pregnant and you’re worried that you might end up welcoming more than one package of joy, Dr. Polyakov assures you that you don’t need to get stressed.
“In general, you can say that once you are pregnant, another pregnancy is almost impossible at the same time.”
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