Fetal cardiac function between 11 and 35 weeks' gestation and nuchal translucency thickness

Area of Science:

• Fetal Medicine
• Cardiology
• Genetics

Background:

• The underlying causes of increased nuchal translucency (NT) in fetuses are not fully understood.
• Cardiac dysfunction is a potential contributor to increased NT.
• Investigating the relationship between NT and cardiac function in fetuses with normal hearts is crucial.

Purpose of the Study:

• To determine if NT thickness correlates with cardiac function in fetuses with structurally normal hearts throughout gestation.
• To explore the association between NT and various echocardiographic parameters of cardiac performance.

Main Methods:

• 191 karyotypically and phenotypically normal fetuses with normal hearts were included.
• Nuchal translucency (NT) was measured, with 104 having increased NT (≥ 95th centile).
• Detailed fetal echocardiography was performed between 11 and 35 weeks' gestation, analyzing multiple cardiac function parameters.

Main Results:

• Cardiac function parameters, including atrioventricular (AV) valve velocities and semilunar valve function, changed significantly with gestational age.
• In early gestation (11-14 weeks), increased NT multiples of the median (MoM) correlated with altered aortic valve acceleration time (AT), tricuspid valve (TV) inflow patterns, and ductus venosus pulsatility index for veins (DV-PIV).
• Later in gestation, changes in pulmonary valve (PV) AT and AV valve inflow patterns were observed with increasing NT-MoMs.

Conclusions:

• Increased NT thickness is associated with impaired right ventricular diastolic function and semilunar valve acceleration time.
• Findings suggest an initial improvement in first-trimester right ventricular relaxation, followed by reduced relaxation later in gestation.
• Discordant ventricular afterload may be present in fetuses with increased NT.