First-Trimester Crown-Rump Length and Embryonic Volume of Fetuses with Structural Congenital Abnormalities Measured in Virtual Reality: An Observational Study

الملخص EN

Background.

With the introduction of three-dimensional (3D) ultrasound it has become possible to measure volumes.

The relative increase in embryonic volume (EV) is much larger than that of the crown-rump length (CRL) over the same time period.

We examined whether EV is a better parameter to determine growth restriction in fetuses with structural congenital abnormalities.

Study Design, Subjects, and Outcome Measures.

CRL and EV were measured using a Virtual Reality (VR) system in prospectively collected 3D ultrasound volumes of 56 fetuses diagnosed with structural congenital abnormalities in the first trimester of pregnancy (gestational age 7+5 to 14+5 weeks).

Measured CRL and EV were converted to z-scores and to percentages of the expected mean using previously published reference curves of euploid fetuses.

The one-sample t-test was performed to test significance.

Results.

The EV was smaller than expected for GA in fetuses with structural congenital abnormalities (−35% p<0.001, z-score −1.44 p<0.001), whereas CRL was not (−6.43% p=0.118, z-score −0.43 p=0.605).

Conclusions.

CRL is a less reliable parameter to determine growth restriction in fetuses with structural congenital abnormalities as compared with EV.

By measuring EV, growth restriction in first-trimester fetuses with structural congenital abnormalities becomes more evident and enables an earlier detection of these cases.