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Unfused amnion and chorion after 14 weeks of gestation: associated fetal structural and chromosomal abnormalities
Author(s) -
Ulm B.,
Ulm M. R.,
Bernaschek G.
Publication year - 1999
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1046/j.1469-0705.1999.13060392.x
Subject(s) - fetus , gestation , trisomy , cystic hygroma , amnion , medicine , aneuploidy , obstetrics , prenatal diagnosis , pregnancy , amniocentesis , down syndrome , karyotype , gynecology , chromosome , biology , genetics , psychiatry , gene
Objective To assess possible associations between delayed chorioamniotic fusion after the end of the first trimester and fetal structural and/or chromosomal abnormalities. Design We prospectively studied 492 fetuses from high‐risk pregnancies between 14 and 18 weeks of gestation by transabdominal ultrasonography. Of these, 60 (12%) had unfused amnion and chorion. Results No additional abnormalities were detected in 28/60 fetuses (47%). Karyotyping was performed in 27/28 cases, and one fetus had trisomy 13 (4%). Ten of 24 fetuses (42%) of this group attending a second mid‐trimester scan after 18 weeks of gestation had abnormal sonographic findings not noted at the initial scan. Thirty‐two of 60 (53%) fetuses had additional abnormalities at the initial scan: cystic hygroma ( n = 12), increased nuchal translucency ( n = 10) and other abnormalities ( n = 10). Karyo‐typing revealed aneuploidy in 13 of 28 fetuses (46%) tested: trisomy 21 ( n = 5), Turner's syndrome ( n = 3), trisomy 18 ( n = 3) and trisomy 13 ( n = 2). Additional fetal abnormalities were detected only at the second scan after 18 weeks of gestation in three of eight fetuses (38%). Conclusions These preliminary data suggest that the sonographic finding of unfused amnion and chorion after 14 weeks of gestation may be associated with fetal structural and/or chromosomal abnormalities. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology