Gestational sac volume measured by three‐dimensional ultrasound at 11 to 13 + 6 weeks of gestation: relation to chromosomal defects

Abstract

The measurement of the GSV at 11 to 13 + 6 weeks of gestation is unlikely to provide useful prediction of the major chromosomal defects. In trisomy 13 and triploidy, the small GSV may be due to early onset fetal growth restriction and reduced amniotic fluid volume. In trisomy 18, the increase in GSV is probably due to the presence of associated fetal abnormalities that interfere with fetal swallowing.