Fetal heart assessment in the first trimester of pregnancy: influence of crown-rump length and maternal body mass index

Objective

To evaluate the influence of the crown-rump length and body mass index onsonographic evaluation of the fetal heart using abdominal and vaginal routes inthe first trimester of pregnancy.

Methods

We conducted a cross-sectional study with 57 pregnant women between 12-14 weeks(CRL≤ 84 mm). We evaluated the following fetal cardiac plans using the abdominaland vaginal routes: four-chamber view, right ventricle outflow tract, leftventricle outflow tract and aortic arch. We used the B-mode, color Doppler andfour-dimensional ultrasonography (spatio-temporal image correlation). To evaluatethe influence of crown-rump length and body mass index in the assessment of fetalcardiac planes, we used the t test unpaired.

Results

There were no statistically significant differences in the rates of success andfailure between abdominal and vaginal routes in relation to body mass index,however, there was a higher failure rate in vaginal assessment using B modeassociated with color Doppler (P<0.01).

Conclusion

The crown-rump length and body mass index had no interference in fetal cardiacassessment in the first trimester of pregnancy.