FIRST TRIMESTER SONOGRAPHIC DETECTION OF FETAL MALFORMATIONS

Vanessa Pincham Grad Dip App Sci (Medical Ultrasonography) AMS, Andrew McLennan FRANZCOG (COGU) Sydney Obstectric and Gynaecological Ultrasound, Sydney NSW

Abstract
Nuchal translucency (NT) screening for chromosomal abnormality has been accompanied by a greater emphasis on screening for structural abnormalities in the first trimester. First trimester ultrasound examination can identify approximately 80% of aneuploidy and 60% of major structural abnormalities. Neck, cranial and abdominal wall defects are well demonstrated in the first trimester. However, it is difficult to define cardiac, spinal and diaphragmatic defects until the second trimester. The finding of an increased NT measurement and a normal karyotype defines a group of patients who require careful second trimester morphological assessment and fetal echocardiography. The 18-20 week ultrasound remains important for cardiac, diaphragmatic, spinal and facial assessment.

Citation
Pincham V and McLennan A. First trimester sonographic detection of fetal malformations. ASUM Bulletin 2001.1:9-14

Keywords
nuchal translucency, obstetric ultrasound, chromosomal abnormality, fetal abnormality, first trimester