The fetal frontomaxillary facial angle in normal and trisomy 21 ultrasounds at 11-13(+6) weeks of gestation: findings among the ethnic Chinese compared with Caucasian

Prenat Diagn. 2013 Aug;33(8):711-5. doi: 10.1002/pd.4084. Epub 2013 May 1.

Abstract

Objective: The aim of this research was to compare the fetal frontomaxillary facial (FMF) angle between normal and trisomy 21 fetuses at 11(+0) -13(+6) weeks gestation in a Chinese population.

Methods: A prospective observational study was performed that included 640 euploid and 45 trisomy 21 singleton pregnancies undergoing first trimester ultrasound screening between 11 and 13(+6) weeks of gestation. The FMF angle was measured in the midsagittal plane using the standard technique.

Results: The fetal mean FMF angle decreased with the increasing crown-rump length (CRL) from 88.6°at a CRL of 45 mm to 78.5° at a CRL of 84 mm (FMF angle = 100.212 - 0.258 × CRL, R(2) = 0.222, p < 0.001). The overall mean FMF angle in the euploid population was 82.9° ± 4.1° and in trisomy 21 cases, 92.3° ± 5.2°.

Conclusions: Fetal FMF angle is affected by gestational age in a Chinese population, although it remains a significant predictor of fetal trisomy 21.

Publication types

  • Comparative Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asian People
  • Down Syndrome / diagnostic imaging*
  • Down Syndrome / ethnology*
  • Face / diagnostic imaging*
  • Face / embryology
  • Female
  • Fetus / anatomy & histology
  • Gestational Age
  • Humans
  • Maxilla / diagnostic imaging*
  • Maxilla / embryology
  • Middle Aged
  • Pregnancy
  • Pregnancy Trimester, First* / ethnology
  • Pregnancy Trimester, Second* / ethnology
  • Ultrasonography, Prenatal / methods*
  • White People
  • Young Adult