The fetal thyroid: normal and abnormal sonographic measurements.

Area of Science:

• Perinatology
• Endocrinology
• Medical Imaging

Background:

• Perinatal thyroid disease can impact fetal development and neonatal health.
• Accurate assessment of fetal thyroid size is crucial for identifying potential risks.
• Normative ultrasound values for fetal thyroid dimensions are not well-established across gestational ages.

Purpose of the Study:

• To establish normative sonographic values for fetal thyroid width and circumference.
• To evaluate the utility of fetal thyroid measurements in predicting neonatal thyroid dysfunction.
• To compare thyroid measurements in fetuses at risk versus those at low risk for thyroid disease.

Main Methods:

• Prospective sonographic evaluation of 31 low-risk fetuses to determine normative thyroid measurements.
• Sonographic examination of 23 fetuses at risk for thyroid disease.
• Comparison of fetal thyroid measurements between at-risk and control groups.
• Correlation of fetal thyroid measurements with neonatal thyroid function at birth.

Main Results:

• Normative fetal thyroid width and circumference values were established for each gestational age.
• Five newborns from the at-risk group presented with goiters and abnormal thyroid function.
• These five neonates had fetal thyroid measurements exceeding the upper limit of the 95% confidence interval.
• Eighteen at-risk fetuses without neonatal thyroid dysfunction had measurements within the normal range.

Conclusions:

• Fetal thyroid sonography can identify fetuses at risk for thyroid dysfunction.
• Elevated fetal thyroid measurements are associated with neonatal goiter and impaired thyroid function.
• Ultrasound-derived fetal thyroid measurements provide valuable predictive information for perinatal thyroid health.