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3D multiplanar evaluation of the fetal heart allows the examiner to identify the outflow tracts using a simple technique that requires only rotation around x- and y-axes from reference images obtained in a transverse sweep through the fetal chest.

When the fetal heart cannot be imaged during the second trimester, these factors should be identified. Using data from this study, the gestational age at which the highest probability of imaging the heart can be determined if the thickness of the adipose tissue and a history of lower abdominal surgery are known.

Imaging of the aortic and pulmonic outflow tracts in the fetus may be difficult owing to fetal position. This study describes two screening methods for imaging the outflow tracts, depending on whether the interventricular septum was tangential (group I) or perpendicular (group II) to the ultrasonic beam. We performed 170 examinations during the second and third trimesters of pregnancy. The outflow tracts were imaged in 166 (97.6%). Fetuses in group I were identified much less frequently (13.2%) than fetuses in group II (86.8%). This study would suggest that for the outflow tracts to be imaged during a screening examination, the sonographer should become familiar with the sonographic anatomy of the outflow tracts when the interventricular septum is perpendicular to the ultrasound beam.

Preterm PROM is associated with changes in fetal cardiac function consistent with increased left ventricular compliance. These observations were also noted in fetuses with microbial invasion of the amniotic cavity. Our findings suggest that fetal cardiac function is altered in preterm PROM and, in particular, in cases with intra-amniotic infection.