Fetal ultrasound has revolutionized fetal medicine over the past four decades, becoming the primary modality for initial assessment of fetal health and development.
Provides normative biometric data including measurements such as head circumference, biparietal diameter, and ventricular size.
Technological Advancements in Fetal Ultrasound
Significant improvements in imaging quality through the development of high-frequency, three-dimensional (3D) transducers.
Transvaginal ultrasound has addressed limitations inherent in transabdominal approaches, such as maternal obesity and early gestational assessments.
Doppler ultrasound has enhanced capabilities to evaluate fetal cerebral and cardiovascular circulation, crucial for diagnosing fetal hypoxemia and cardiovascular anomalies (Baschat et al. 2001; Donofrio et al. 2003).
Three-Dimensional and Four-Dimensional Ultrasound Applications
3D ultrasound is primarily utilized for detailed volumetric measurements and evaluation of craniofacial and skeletal anomalies (Merz et al. 2012; Merz and Abramowicz, 2012; Chen et al. 2005; Cassart et al. 2007).
Provides surface rendering that aids in detailed fetal morphology assessments.
Four-dimensional (4D) ultrasound enables real-time observation of fetal movements and behavior, expanding potential diagnostic insights into neurological development and behavioral patterns (Kurjak et al. 2012; Sato et al. 2014).
Standard Screening Protocols and Timing
Protocols for ultrasound screening differ regionally but generally include:
First trimester ultrasound:
Confirms fetal viability through detection of fetal heartbeat.
Establishes accurate gestational age.
Utilizes measurements like nuchal translucency combined with maternal biochemical markers to screen for aneuploidies and significant anomalies.
Increasingly used for early detection of congenital anomalies, notably congenital heart defects (Persico et al. 2011; Johnson and Simpson 2007).
Second trimester ultrasound (18-22 weeks):
Performs a comprehensive anatomical survey capable of detecting the majority of major fetal anomalies.
A normal first trimester scan does not obviate the need for a detailed anatomical ultrasound at this stage.
