The use of color Doppler ultrasound to identify fetuses at increased risk for trisomy 21: an alternative for high-risk patients who decline genetic amniocentesis

Obstet Gynecol. 1995 Mar;85(3):378-86. doi: 10.1016/0029-7844(94)00384-P.


Objective: To compare color Doppler ultrasound with real-time ultrasound to determine whether it increased the identification of fetuses with trisomy 21.

Methods: Consecutive fetuses with a second trimester risk greater than 1:270 for trisomy 21 were examined with real-time ultrasound (n = 1028) or real-time plus color Doppler ultrasound (n = 1028) before second trimester genetic amniocentesis. The type of abnormal ultrasound findings were compared between fetuses with normal and abnormal chromosomes. Using the Bayes theorem, the ultrasound-adjusted maternal age-related risk (posterior risk) for trisomy 21 was computed after a normal or abnormal real-time plus color Doppler examination.

Results: A significantly greater number of fetuses with trisomy 21 (87% [13 of 15] versus 29% [5 of 17], P < .002) were identified with real-time plus color Doppler than with real-time ultrasound. Color Doppler ultrasound identified a significantly higher rate of cardiovascular abnormalities in fetuses with trisomy 21 (60% [9 of 15] versus 12% [2 of 17], P < .008) than did real-time ultrasound. Identification of abnormal fetal anatomy using real-time plus color Doppler in patients 35 years and older increases the likelihood of detecting trisomy 21. A normal real-time plus color Doppler examination of the fetus decreases the risk for trisomy 21 to less than 1:270 until the maternal age of 42, above which the risk for trisomy 21 is greater than 1:270.

Conclusion: Real-time plus color Doppler ultrasound examination of the fetus is an alternative for the identification of trisomy 21 for patients who may decline genetic amniocentesis based on their age-related risk.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Amniocentesis
  • Down Syndrome / diagnostic imaging*
  • Female
  • Humans
  • Maternal Age
  • Middle Aged
  • Pregnancy
  • Pregnancy, High-Risk
  • Prospective Studies
  • Sensitivity and Specificity
  • Ultrasonography, Doppler, Color*
  • Ultrasonography, Prenatal / methods*