Superfetation as a Cause of Growth Discordance in a Multiple Pregnancy

Harrison, Adele; Valenzuela, Alejandra; Gardiner, Joseph; Sargent, Michael A.; Chessex, Philippe

doi:10.1016/j.jpeds.2005.04.038

Cited by 13 publications

(12 citation statements)

References 9 publications

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“…However, there is good evidence for SF in humans resulting from the use of artificial reproductive technologies (Bonnar, 1865; Walter, Hasenohr & Kerin, 1975; Soudre et al , 1992; Dmowsky, De Orio & Rana, 1997; Steck & Bussen, 1997). Harrison et al (2005) demonstrated discordance in development after the transfer of three embryos. After birth of three fetuses with growth discordance it was demonstrated by the method of ultrasound scanning of the developing gyri and sulci of the fetuses in question that there must have been two implantations from the embryo transfer and another spontaneous fertilization and implantation after another three weeks.…”

Section: Evidence For Superfetation In Mammalsmentioning

confidence: 99%

“…Ultrasound examination is very reliable for determining gestational age (Slagle, Oliphant & Gross, 1989). Harrison et al (2005) suggest that ultrasound scanning and morphological evidence during the first trimester are required for a definite diagnosis of SF. Other cases of idiopathic SF in humans appear to have been caused by endogenous reproductive complications such as the presence of ectopic pregnancy (Hartel, 1958; Honore & Nickerson, 1977; Van Dam, Vanderheyden & Uyttenbroeck, 1988; Kobayashi et al , 1996) and in a case of bicornuate uterus (Singhal et al , 2003), a rare uterine abnormality.…”

Section: Evidence For Superfetation In Mammalsmentioning

confidence: 99%

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The concept of superfetation: a critical review on a ‘myth’ in mammalian reproduction

et al. 2010

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Superfetation is understood as another conception during an already ongoing pregnancy. This implies the existence of young of different developmental stages within the female reproductive tract during certain periods of pregnancy. Nevertheless, a clear definition of the term as well as distinct criteria to identify the occurrence of superfetation in a species is missing. The variable anatomy of mammalian reproductive tracts seems to make the occurrence of superfetation more or less likely but impedes the simple evaluation of whether it is present or not. Additionally, adequate determination methods are missing or are difficult to apply at the right time. Superfetation or rather superfetation-like pregnancies are reported for numerous species including humans, livestock and rodents. The usual criteria to assume a case of superfetation include the finding of discordantly developed young within the uterus during post mortem or parturition of young after a birth interval shorter than the assumed pregnancy length. Often the occurrence of superfetation is concluded because other explanations of reproductive artifacts are missing. Even severe reproductive pathologies are often confused with superfetation. True superfetation or superfetation as a reproductive strategy may exist in some mammals. In the American mink (Neovison (Mustela) vison) and the European badger (Meles meles) superfetation occurs in combination with embryonic diapause. In the European brown hare (Lepus europaeus), superfetation has long been assumed to exist but evidence is still controversial. Superfetation definitely occurs in certain species of poeciliid and zenarchopterid fish, some of which also exhibit viviparity and maternal care. In mammals, the evolution of such a reproductive mechanism poses many interesting evolutionary, endocrine, microbial and immunological questions that require further investigation. Here we review the scant and at times ancient literature on this poorly understood topic. The different manifestations of superfetation are defined and reliable criteria to detect superfetation are outlined. Also, the differentiation of superfetation into a reproductive strategy or as a disrupted, abnormal reproductive function is discussed. Due to the different discussed functional aspects of superfetation, it is appropriate to establish a more detailed scheme to classify the true natural superfetation cases into superfertilization, superconception and superfetation proper. To date, there is no mammal species known for which superfetation proper in terms of finding discordantly developed fetuses has been conclusively demonstrated to be not only a rare occurence but an evolved reproductive strategy.

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Section: Evidence For Superfetation In Mammalsmentioning

confidence: 99%

Section: Evidence For Superfetation In Mammalsmentioning

confidence: 99%

The concept of superfetation: a critical review on a ‘myth’ in mammalian reproduction

et al. 2010

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“…However the work of Kuhns et al [3] suggest that the age of calcification of the crowns of the molars is not affected by IUGR and we use this criterion along with the New Ballard Score and the ophthalmic examination to confirm the disparity in gestational ages of the neonates. Harrison et al [6] have recently reported a case of superfoetation and suggested that in growth-discrepant multiple deliveries, skilled neurosonography and ophthalmic examination may be used to support the diagnosis of superfoetation when detailed first trimester data is lacking. We would like to add the role of the New Ballard Scoring and, as they may help clinch the diagnosis, even where suggestive fortuitous circumstances as in this case (distinct marker separating the two fertilizations in the form of bleeding on implantation of first ovum) are not available.…”

Section: Resultsmentioning

confidence: 99%

Discordant twins with the smaller baby appropriate for gestational age – unusual manifestation of superfoetation: A case report

et al. 2007

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Background: Documentation of superfoetation is extremely rare in humans., The younger foetus has invariably been small for gestational age (estimated from the date of the last menstrual bleed) in all the cases reported in the literature. We report a case where the younger twin was of appropriate size for gestation.Case Presentation: The first of twins was of 32 weeks gestation and the baby was of appropriate size and development for the gestational age. The second twin was of 36 weeks gestation. Gestational age was estimated with the New Ballard score, x-ray of the lower limbs, dental age on x-ray, and ophthalmic examination. Conclusion:Bleeding on implantation of the first foetus probably helped demarcate the two pregnancies. Dental age and the New Ballard score can be used to diagnose superfoetation in discordant twins, when detailed first trimester ultra-sound data is not available.

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“…Confirmation requires ultrasound scanning during the first trimester, but neurosonography with detailed ophthalmic examination may support the diagnosis. Superfetation has innumerous antenatal implications although it is very difficult to retrospectively confirm the diagnosis postnatally [36]. Considering the absence of substantial evidence, we believe the superfetation mechanism could only be possible in theory.…”

Section: Other Forms Of Multiple Gestationmentioning

confidence: 90%