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Pregnant twice in one cycle – gynecologist explains the phenomenon

It happens very rarely, but it can happen: Women become pregnant a second time during pregnancy. Tikbow asked a gynecologist how this is possible and what it means for mother and child(ren).

Last year, a woman in China had twins. A DNA test gave the supposed father a severe shock: the children are not siblings, but half-siblings! So they have two different fathers. A similar case made headlines in the USA in 2015. Here, too, a woman had fraternal twins from two different men. She had had sex with them a few days apart. In such a case, a woman is said to be pregnant twice in the same cycle. This happens very rarely, but it is possible,” confirms Dr. Mandy Mangler, head of the Department of Gynecology and Obstetrics at the Vivantes Auguste Viktoria Clinic in Berlin.

Pregnant again during pregnancy – how can this happen?

A distinction is made between superfecundation and superfecundation. In superfecundation, one egg is fertilized and while it is still on its way to the mother, another egg pops up and is also fertilized. If you only have sex with a man, you probably don’t notice anything. The woman is simply pregnant with twins,” explains Mandy Mangler, MD.

In superfötation, unlike superfecundation, the pregnancy is already implanted. This means that the fertilized egg has already implanted itself in the uterus. If another egg then pops and is fertilized, this is called superfötation. But that is virtually impossible in humans," says the gynecologist. Normally, the hormone balance in women changes so quickly after implantation that no more eggs can hatch;

Recognizing pregnancy

A pregnancy is often only noticed when a DNA test shows that the twins have two different fathers. Sometimes, however, it can also be detected during pregnancy. The ultrasound then shows that the children are different sizes. This can be an indication of pregnancy. But it may also be that the twins are simply developing differently," says the gynecologist. The ultrasound therefore does not provide a clear result;

Risks of pregnancy

Pregnancy is not dangerous in itself. However, it means that one of the twins – nämlich the later conceived – comes a little too early into the world. "You can’t have the children at a later time, but when one child is born, the other is automatically born as well", says Mandy Mangler, MD. "That is because of the hormones. They cause both children to be born at the same time";

Malformations favor "pregnancy

Pregnancy is so rare that there is no need to fear it, emphasizes the expert in gynecology and obstetrics. Exceptions are women with two uteruses or two half uteruses or two vaginas. In these cases it can happen that two pregnancies are created in two different wombs;