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First trimester sonographic detection of chromosomal abnormalities in an unselected population
Author(s) -
Economides Demetrios L.,
Whitlow Barry J.,
Kadir Rezan,
Lazanakis Michael,
Verdin Stuart M.
Publication year - 1998
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.1998.tb09351.x
Subject(s) - trisomy , medicine , nuchal translucency , obstetrics , fetus , gestational age , nuchal translucency measurement , abnormality , population , first trimester , gynecology , aneuploidy , pregnancy , biology , chromosome , biochemistry , genetics , environmental health , psychiatry , gene
Objective To investigate the role of first trimester sonography in detecting chromosomal abnormalities in an unselected obstetric population. Methods 2281 women (mean maternal age 30 years [range 16‐47]; mean gestational age 12 +3 weeks [range 11‐14]) underwent transabdominal scanning to assess fetal structure and, if anatomical survey was considered to be incomplete (31% of cases), transvaginal sonography was also performed. Measurement of nuchal translucency was included and karyotyping performed as considered appropriate. Results There were 16 chromosomal abnormalities; 13 (81%) were diagnosed at 11‐14 weeks either because of a nuchal translucency greater than or equal to the 99th centile for gestational age (7/16; 44% [95% CI 25‐63]) or due to the presence of structural abnormalities (6/16; 38% [95%CI 14.2–61.81). Seventy‐five percent of cases of trisomy 21 were also diagnosed either because of having a nuchal translucency greater than or equal to the 99th centile (5/8; 63%) or due to the presence of a structural abnormality (1/8; 13%). Conclusions A significant proportion of fetal chromosomal abnormalities can be detected by first trimester sonographic screening to assess fetal structural appearance. The sensitivity of detection can be improved by combining measurement of nuchal translucency with detailed examination of fetal anatomy.