| Vanishing twin | |
|---|---|
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| A fetus papyraceus shown with its umbilical cord next to the placenta of its dichorionic diamniotic twin | |
| Specialty |
Obstetrics and gynaecology 
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A vanishing twin, also known as twin resorption, is a fetus in a multigestation pregnancy that dies in utero and is then partially or completely reabsorbed. In some instances, the dead twin is compressed into a flattened, parchment-like state known as fetus papyraceus.
Vanishing twins occur in up to one of every eight multifetus pregnancies and may not even be known in most cases. "High resorption rates, which cannot be explained on the basis of the expected abortion rate, suggest intense fetal competition for space, nutrition, or other factors during early gestation, with frequent loss or resorption of the other twin(s)."
In pregnancies achieved by in vitro fertilization, "it frequently happens that more than one amniotic sac can be seen in early pregnancy, whereas a few weeks later there is only one to be seen and the other has 'vanished'".
See also
Further reading
- Landy HJ, Keith LG (1998). "The vanishing twin: a review". Human Reproduction Update. 4 (2): 177–183. doi:10.1093/humupd/4.2.177. PMID 9683354.
- Medland SE, Wright MJ, Geffen GM, Hay DA, Levy F, Martin NG, Duffy DL (April 2003). "Special twin environments, genetic influences and their effects on the handedness of twins and their siblings". Twin Research. 6 (2): 119–130. doi:10.1375/136905203321536245. PMID 12723998. S2CID 18780721.
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Pharoah PO, Price TS, Plomin R (September 2002). "Cerebral palsy in twins: a national study". Archives of Disease in Childhood. Fetal and Neonatal Edition. 87 (2): F122–F124. doi:10.1136/fn.87.2.F122. PMC 1721448. PMID 12193519.
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