Items tagged “second trimester”

The lemon sign, noted on antenatal imaging, is one of the many notable fruit-inspired signs. It is a feature when there appears to be an indentation of the frontal bone (depicting that of a lemon). It is classically seen as a sign of a Chiari II malformation and also seen in the majority (90-98%...

The nuchal fold is a normal fold of skin seen at the back of the fetal neck during the second trimester of pregnancy. Increased thickness of the nuchal fold is a soft marker associated with multiple fetal anomalies, and is measured on a routine second trimester ultrasound.  Terminology It shou...

Echogenic intracardiac focus (EIF) is a relatively common sonographic observation that may be present on an antenatal ultrasound scan. Epidemiology They are thought to be present in ~4-5% of karyotypically normal fetuses. They may be more common in the Asian population 5. Associations trisom...

Antenatal soft ultrasound markers are fetal sonographic findings that are generally not abnormalities as such but are indicative of an increased age-adjusted risk of an underlying fetal aneuploidic or certain non-chromosomal abnormalities. Most of the described features do not constitute a stru...

Fetal ventriculomegaly refers to the presence of dilated cerebral ventricles in utero. Important in itself, it is also associated with other CNS anomalies. Epidemiology Using the current sonographic cut-off criteria (see radiographic features below), the estimated prevalence may be at ~0.9% o...

Absent end-diastolic flow (AEDF) in an umbilical artery Doppler assessment is a useful feature that indicates underlying fetal vascular stress if detected in mid or late pregnancy. It is often classified as Class II in severity in abnormal umbilical arterial Dopplers 9. Epidemiology Associatio...

Non-visualization of the fetal stomach on ultrasound can occur with various physiological as well as pathological processes. It becomes a significant sonographic observation >14 weeks of gestation (about the time the fetus begins to swallow). Causes include: physiological emptying: transient ...

The four chamber cardiac view is an important and routinely performed view in both fetal echocardiography as well as on a standard second trimester anatomy scan. Detectable pathology The four chamber view can only detect some of the congenital cardiac anomalies (~64% according to one study 2) ...

Head circumference (HC) is one of the basic biometric parameters used to assess fetal size. HC together with biparietal diameter (BPD), abdominal circumference (AC), and femur length (FL) are computed to produce an estimate of fetal weight. In the second trimester, this may be extrapolated to an...

Fetal ventriculomegaly (ventricle width >10 mm) is an important finding in itself and it is also associated with other central nervous system abnormalities. For more information, see the main article fetal ventriculomegaly. Differential diagnosis Fetal ventriculomegaly can be thought of in ter...

The left ventricular outflow tract (LVOT) view (or five chamber view) is one of the standard views in a fetal echocardiogram. It is a long-axis view of the heart, highlighting the path from the left ventricle into the ascending aorta (left ventricle outflow tract). In this view, the right vent...

The quadruple screening test, also known as the quad screen, AFP Plus quad test or multiple marker screening test, is a maternal antenatal screening blood test that can be used in conjunction with other investigations e.g. ultrasound soft markers, to estimate the risk of aneuploidy 1.  This is ...