As one literature report begins,
The topic is superfetation – the phenomenon of becoming pregnant whilst already pregnant.
It happens in humans (we think). And hares[2]. It’s been documented in badgers, mink, panthers, buffalo, wallaby, rats, mice, rabbits, horses, sheep, kangaroos, sugar gliders and cats. But much of the evidence is dubious, and remains controversial. The only agreed incidents seem to be documented in fish that carry their young – the poecilid and zenarchopterid.
Superfetation shouldn’t happen. Once conception has occurred, hormones are released that prevent further ovulation, and a mucus plug blocks up the womb.
But does it happen from time to time anyway?
“Here we review the scant and at times ancient literature on this poorly understood topic.”[1]
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| European hare. By Jean-Jacques Boujot via Wikipedia Commons. |
Superfetation shouldn’t happen. Once conception has occurred, hormones are released that prevent further ovulation, and a mucus plug blocks up the womb.
But does it happen from time to time anyway?
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