Biomaterial Database

The ultrasonographic prediction of chorionicity in twin gestation. 1989

M E D'Alton, and D K Dudley

Department of Obstetrics and Gynecology, Ottawa Civic Hospital, Ontario, Canada.

In a prospective study of 69 consecutive twin gestations, chorionicity was assessed ultrasonographically, by the new technique of counting the number of layers visualized in the dividing membrane. For purposes of the study the antenatal categorization of chorionic type was based only on the number of layers observed. The pregnancy was classified as monochorionic when only two layers were identified and as dichorionic if three or four layers were seen. Confirmation of chorionic type was obtained after delivery by histopathologic examination of the placenta. The ultrasonographic technique used correctly determined chorionicity in 68 of 69 twin pregnancies. The predictive accuracy was 100% for 51 pregnancies designated by ultrasonography as dichorionic and 94.4% for 18 pregnancies considered to be monochorionic. These results suggest that counting the number of layers seen in fetal membranes by ultrasonography examination is an accurate way of determining chorionicity in twin gestation.

UI	MeSH Term	Description	Entries
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011272	Pregnancy, Multiple	The condition of carrying two or more FETUSES simultaneously.	Multiple Pregnancy,Multiple Pregnancies,Pregnancies, Multiple
D002823	Chorion	The outermost extra-embryonic membrane surrounding the developing embryo. In REPTILES and BIRDS, it adheres to the shell and allows exchange of gases between the egg and its environment. In MAMMALS, the chorion evolves into the fetal contribution of the PLACENTA.	Chorions
D005260	Female		Females
D005313	Fetal Death	Death of the developing young in utero. BIRTH of a dead FETUS is STILLBIRTH.	Fetal Mummification,Fetal Demise,Death, Fetal,Deaths, Fetal,Demise, Fetal,Fetal Deaths,Mummification, Fetal
D005544	Forecasting	The prediction or projection of the nature of future problems or existing conditions based upon the extrapolation or interpretation of existing scientific data or by the application of scientific methodology.	Futurology,Projections and Predictions,Future,Predictions and Projections
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000653	Amniotic Fluid	A clear, yellowish liquid that envelopes the FETUS inside the sac of AMNION. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (AMNIOCENTESIS).	Amniotic Fluid Index,Amniotic Fluid Indices,Amniotic Fluids,Fluid Index, Amniotic,Fluid Indices, Amniotic,Fluid, Amniotic,Fluids, Amniotic,Index, Amniotic Fluid,Indices, Amniotic Fluid
D014427	Twins	Two individuals derived from two FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother. Twins are either monozygotic (TWINS, MONOZYGOTIC) or dizygotic (TWINS, DIZYGOTIC).	Twin
D014463	Ultrasonography	The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.	Echography,Echotomography,Echotomography, Computer,Sonography, Medical,Tomography, Ultrasonic,Ultrasonic Diagnosis,Ultrasonic Imaging,Ultrasonographic Imaging,Computer Echotomography,Diagnosis, Ultrasonic,Diagnostic Ultrasound,Ultrasonic Tomography,Ultrasound Imaging,Diagnoses, Ultrasonic,Diagnostic Ultrasounds,Imaging, Ultrasonic,Imaging, Ultrasonographic,Imaging, Ultrasound,Imagings, Ultrasonographic,Imagings, Ultrasound,Medical Sonography,Ultrasonic Diagnoses,Ultrasonographic Imagings,Ultrasound, Diagnostic,Ultrasounds, Diagnostic