Shortening fraction of the right ventricle: a comparison between euploid and trisomy 21 fetuses at week 11 to week 13 and 6 days of gestation.

ABSTRACT

OBJECTIVES: This study was designed to compare the first trimester shortening fraction of the right ventricle (SFRV) values between euploid fetuses and fetuses with trisomy 21. METHODS: SFRV was measured in 58 first trimester fetuses between September 2008 and February 2010. The stored M-mode images were used to obtain the right ventricular diastolic diameter (RVDD) and right ventricular systolic diameter (RVSD) measurements offline. RESULTS: The SFRV values were found to be significantly greater in the 9 fetuses with trisomy 21 as compared to the group of 49 euploid fetuses (mean 48.6 mm; range 36-56.25 mm vs mean 34.11 mm; range 22.73-43.48 mm) (p < 0.0001). The RVDD measurements were also found to be significantly greater in the fetuses with trisomy 21 than in the euploid fetuses (mean 3.08 mm; range 2.2-4.7 mm vs mean 2.54 mm; range 1.9-3.6 mm) (p = 0.03).There was no difference in the RVSD measurements between the two groups [mean 1.56 mm; range 1.2-2.3 mm (trisomy 21 fetuses) vs mean 1.67 mm; range 1.3-2.4 mm (euploid fetuses)] (p = 0.17). CONCLUSIONS: The SFRV values in fetuses with trisomy 21 appear to be significantly greater than in the euploid fetuses. The RVDD also appears to be greater in fetuses with trisomy 21 than in the euploid fetuses.