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Twin Study: Relationship between Birth Weight, Zygosity, Placentation, and Pathologic Placental Changes

Published online by Cambridge University Press:  01 August 2014

M.A. Ramos-Arroyo
Department of Medical Genetics, Indiana University School of Medicine, Indianapolis, USA
T.M. Ulbright*
Department of Pathology, Indiana University School of Medicine, Indianapolis, USA
P.-L. Yu
Department of Medical Genetics, Indiana University School of Medicine, Indianapolis, USA
J.C. Christian
Department of Medical Genetics, Indiana University School of Medicine, Indianapolis, USA
Department of Pathology, Indiana University Hospital – N340, Indianapolis, IN 46223, USA


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We examined the placentas of 182 like-sexed live-born twins: 73 placentas (40.1%) were monochorionic and 109 (59.9%) were dichorionic. All twin pairs with monochorionic placentas were monozygotic (MZ), but 28.9% of pairs with dichorionic placentas were MZ. Analysis of birth weights demonstrated that dichorionic and dizygotic (DZ) twins were heaviest, and suggested that the chorion status is a more important determinant of birth weight than zygosity. Vascular anastomoses were identified only in monochorionic placentas and occurred in 79.5% of cases. All placentas with deep anastomoses had superficial anastomoses. A higher proportion of velamentous and marginai insertions of the umbilical cord in monochorionic placentas (27.4%) compared to dichorionic placentas (13.8%) supports the belief that lateral placental growth is greatest in twin gestations in which the embryos are initially most closely apposed — The theory of trophotropism.

Research Article
Copyright © The International Society for Twin Studies 1988



1. Adler, UP (1949): Investigation of vascular relations in the twin placenta and their importance (dissertation). Berne.Google Scholar
2. Arts, NFTh, Lohman, HM (1971): The vascular anatomy of monochorionic diamniotic twin placentas and the transfusion syndrome. Europ J Obstet Gynecol 3:8693.Google Scholar
3. Benirschke, K (1961): Accurate recording of twin placentation. A plea to the obstetrician. Obstet Gynecol 18:334347.Google Scholar
4. Benirschke, K (1961): Examination of the placenta. Obstet Gynecol 18:309333.Google Scholar
5. Benirschke, K (1965): Major pathologic features of the placenta, cord and membranes. Birth Defects Originai Artide Series 1:5263.Google Scholar
6. Benirschke, K, Bourne, GL (1960): The incidence and prognostic implication of congenital absence of one umbilical artery. Am J Obstet Gynecol 79:251254.Google Scholar
7. Benirschke, K, Driscoll, SG (1967): The Pathology of the Human Placenta. New York: Springer-Verlag.Google Scholar
8. Bhargava, I, Chakravarty, A, Raja, PTK (1971): An anatomical study of the foetal blood vessels on the chorial surface of the human placenta. Acta Anat 80:465479.Google Scholar
9. Bhargava, I (1976): Blood vessels of the twin placenta in relation to zygosity. Acta Genet Med Gemellol 25:121124.Google Scholar
10. Bleisch, VS (1965): Placental circulation of human twins. Am J Obstet Gynecol 91:862869.Google Scholar
11. Bulmer, MG (1970): The Biology of Twinning in Man. Oxford: Claredon Press.Google Scholar
12. Buzzard, IM, Uchida, IA, Norton, JA, Christian, JC (1983): Birth weight and placental proximity in Uke-sexed twins. Am J Hum Genet 35:318323.Google Scholar
13. Corey, LA, Kang, KW, Christian, JC, Norton, JA Jr, Harris, RE, Nance, WE (1976): Effects of chorion type on variation in cord blood cholesterol of monozygotic twins. Am J Hum Genet 28:433441.Google Scholar
14. Corey, LA, Nance, WE, Kang, KW, Christian, JC (1979): Effects of type of placentation on birth weight and its variability on monozygotic and dizygotic twins. Acta Genet Med Gemellol 28:4150.Google Scholar
15. Heifetz, SA (1983): Single umbilical artery: A statistical analysis of 237 autopsy cases (abstract). Lab Invest 48:6P.Google Scholar
16. Hyrtl, J (1970): Die Blutgefasse des Menschlichen Nachgeburt (The blood vessels of the human placenta). Vienna: W. Braumulier.Google Scholar
17. Kloosterman, GJ (1963): The third circulation in identical twins. Ned T Verlosk 63:395412.Google Scholar
18. Nylander, PPS (1976): The value of the placenta in the determination of zygosity – a study of 1,252 Nigerian twin maternities. Obstet Gynaecol Brit Cmwlth 76:699704.Google Scholar
19. Rausen, AR, Seki, M, Straus, L (1965): Twin transfusion syndrome. A review of 19 cases studied at one institution. J Pediat 66:613628.Google Scholar
20. Reed, T, Uchida, IA, Norton, JA Jr, Christian, JC (1978): Comparison of dermatoglyphic patterns in monochorionic and dichorionic, monozygotic twins. Am J Hum Genet 30:383391.Google Scholar
21. Rose, RJ, Uchida, IA, Christian, JC (1981): Placentation effects on cognitive resemblance of adult monozygotes. Prog Clin Biol Res Pt B:3541.Google Scholar
22. Schatz, F (1900): Klinische Beitrage zur Physiologie des Fotus (Clinical observations on the physiology of the fetus). Berlin: A Hirschwals.Google Scholar