First trimester size charts of embryonic brain structures

Area of Science:

• Medical Imaging
• Embryology
• Fetal Development

Background:

• Previous non-invasive measurements of embryonic brain structures relied on 2D-US or 3D-US, with limited focus on specific brain walls.
• Advancements in transvaginal ultrasound technology enable precise, non-invasive measurement of embryonic brain structures.

Purpose of the Study:

• To determine if reliable size charts of human embryonic brain structures can be generated from three-dimensional ultrasound (3D-US) visualizations.
• To establish non-invasive measurement standards for diencephalon, mesencephalon, and telencephalon walls.

Main Methods:

• A prospective periconceptional cohort study included 141 pregnancies monitored until delivery.
• 596 3D-US scans from 106 singleton pregnancies (7-12 weeks GA) were analyzed for embryonic brain structure dimensions.
• Measurements included thickness of diencephalon, mesencephalon, telencephalon, and diameter of diencephalon and mesencephalon using 4D View software.

Main Results:

• 161 (27%) high-quality scans from 79 pregnancies were eligible for analysis.
• Excellent reliability (ICC > 0.98) was found for all embryonic brain structure measurements.
• Good agreement was observed for most measurements, with moderate agreement for the telencephalon.

Conclusions:

• Reliable size charts for human embryonic brain structures can be created from high-quality 3D-US images.
• The low percentage of high-quality scans (27%) highlights a limitation.
• These charts can facilitate future research on normal/abnormal brain development and effects of maternal exposures.