from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Formation or development of a second fetus when one is already present in the uterus, occurring normally in some animal species.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. An excessive accumulation; a superfluous addition.
  • n. The formation of a fetus while another fetus is already present in the uterus.

from the GNU version of the Collaborative International Dictionary of English

  • n. The formation of a fetus at the result of an impregnation occurring after another impregnation but before the birth of the offspring produced by it. This is possible only when there is a double uterus, or where menstruation persists up to the time of the second impregnation.

from The Century Dictionary and Cyclopedia

  • n. A second conception some time after a prior one, by which two fetuses of different age exist together in the same female: often used figuratively.
  • n. The fetus produced by superfetation; hence, any excrescent growth.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. fertilization of a second ovum after a pregnancy has begun; results in two fetuses of different ages in the uterus at the same time


from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin superfetare ("conceive while pregnant"), from super- +‎ fetus.


  • There have been only 10 recorded cases of the phenomenon, dubbed superfetation. Top Stories

  • It's called "superfetation," and I guess it happens... not only can you get pregnant while on your period, etc., I guess you can get pregnant ANYTIME.

    Archive 2009-09-01

  • She addressed the controller of excise as “M. Chatelet,” and left that gentleman thunderstruck by the discovery that she knew about the illegal superfetation of the particle.

    Two Poets

  • Erasistratus, that superfetation may happen to women as to irrational creatures; for, if the womb be well purged and very clean, then there can be divers births.

    Essays and Miscellanies

  • The birth of twins is an evil portent to the Mpongwes, as it is in many parts of Central Africa, and even in the New World; it also involves the idea of moral turpitude, as if the woman were one of the lower animals, capable of superfetation.

    Two Trips to Gorilla Land and the Cataracts of the Congo

  • Neither from the beginning would it ever admit of any additions unto it, but what came from the same fountain of divine revelation and inspiration, clearing itself, in all ages, from all addition and superfetation of men whatever.


  • Transports, that escape from the Gallows, to the Plantations abroad, and a superfetation of Felons, to give a little Business to our Judges,

    A Dialogue Between Dean Swift and Tho. Prior, Esq. In the Isles of St. Patrick's Church, Dublin, On that Memorable Day, October 9th, 1753

  • Argles 2.39 mentions simultaneous extrauterine fetation and superfetation.

    Anomalies and Curiosities of Medicine

  • Pliny speaks of a slave who bore two infants, one resembling the master, the other a man with whom she had intercourse, and cites the case as one of superfetation.

    Anomalies and Curiosities of Medicine

  • The most curious and convincing examples of superfetation are those in which children of different colors, either twins or near the same age, are born to the same woman, -- similar to that exemplified in the case of the mare who was covered first by a stallion and a quarter of an hour later by an ass, and gave birth at one parturition to a horse and a mule.

    Anomalies and Curiosities of Medicine


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  • In the beginning was the Word.

    Superfetation of τὸ ἔν,

    And at the mensual turn of time

    Produced enervate Origen.

    T. S. Eliot

    November 9, 2010

  • Baby, oh baby!

    September 27, 2009

  • Not an obsession with Greek cheese.

    November 5, 2008