title: Effects of Intrauterine Environment on the Magnitude of Differences Within the Pairs of Monozygotic and Dizygotic Twins.
abstract: The aim of this study was to determine the effects of intrauterine environment on the magnitude of intrapair differences in six somatic traits of monozygotic (MZ) and dizygotic (DZ) twins (1,263 pairs; 424 MZ twins and 839 DZ twins). Differences in intrauterine environments of MZ twins enforced division of the research material into four groups: (1) MZ-MC-TTTS - MZ twins from monochorionic (MC) pregnancies with twin-to-twin transfusion syndrome (TTTS), (2) MZ-MC (without TTTS)-MZ twins from MC pregnancies without TTTS, (3) MZ-DC-MZ twins from dichorionic (DC) pregnancies, and (4) DZ-DZ twins. The intrapair differences in all analyzed somatic traits, especially body weight and circumference of the chest, were the largest in the case of MZ twins from MC pregnancies with TTTS. DZ twins were the group presenting with the second largest intrapair differences in the analyzed traits. At the end of pregnancy, that is, in lunar months 9 and 10, the magnitude of intrapair differences in all traits of twins from this group was significantly greater than in MZ twins from both MC and DC pregnancies. Irrespective of the analyzed period, the least evident, statistically insignificant intrapair differences in the studied traits were documented in the case of MZ twins from MC pregnancies without TTTS and twins from DC pregnancies. These findings imply that the differentiating effect of intrauterine environment is associated with the occurrence of TTTS, rather than with chorionicity, as postulated previously.
authors.affiliation: Department of Functional Anatomy,University School of Physical Education,Poznan,Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Waszak
authors.affiliation: Department of Functional Anatomy,University School of Physical Education,Poznan,Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Cieślik
authors.affiliation: Institute of Human Genetics,Polish Academy of Sciences,Poznan,Poland.
authors.forename: Marzena
authors.initials: M
authors.lastname: Skrzypczak-Zielińska
authors.affiliation: Institute of Human Genetics,Polish Academy of Sciences,Poznan,Poland.
authors.forename: Marlena
authors.initials: M
authors.lastname: Szalata
authors.affiliation: Department of Biotechnology and Molecular Biology,Institute of Natural Fibres and Medicinal Plants,Poznan,Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Wielgus
authors.affiliation: Institute of Human Genetics,Polish Academy of Sciences,Poznan,Poland.
authors.forename: Oliwia
authors.initials: O
authors.lastname: Zakerska-Banaszak
authors.affiliation: Department of Perinatology and Gynaecology,University of Medical Sciences,Poznan,Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bręborowicz
authors.affiliation: Institute of Human Genetics,Polish Academy of Sciences,Poznan,Poland.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Słomski
mesh_terms: D001835:Body Weight; D002823:Chorion / Q000503:physiopathology*; D005260:Female; D005330:Fetofetal Transfusion / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D059285:Pregnancy, Twin / Q000235:genetics / Q000502:physiology*; D011296:Prenatal Diagnosis; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics
keywords: chorion in multiple pregnancies; dichorionic placenta; monochorionic placenta; twin-to-twin transfusion syndrome