First-trimester reference centiles of fetal biometry in Indian population

Area of Science:

• Maternal-fetal medicine
• Prenatal diagnostics
• Human fetal growth

Background:

• Accurate fetal biometry is crucial for monitoring pregnancy progression.
• Existing biometric charts may not fully represent diverse populations like the Indian subcontinent.
• Establishing population-specific reference data is essential for precise gestational age estimation.

Purpose of the Study:

• To develop crown-rump length (CRL)-based biometric charts for fetuses in the first trimester.
• To provide a reference standard tailored for the Indian population.
• To correlate CRL with other key fetal parameters.

Main Methods:

• Cross-sectional study involving 400 singleton pregnancies with normal outcomes (11-14 weeks gestation).
• Linear regression models were employed to establish relationships between CRL and other biometric measurements.
• Mean and standard deviation (SD) were derived as functions of CRL.

Main Results:

• Positive correlations were observed between CRL and nuchal translucency (NT), biparietal diameter (BPD), occipito-frontal diameter (OFD), lateral ventricular diameter (LV), abdominal circumference (AC), femur length (FL), and fetal weight (FW).
• Regression models and centile charts for NT, BPD, OFD, LV, AC, and FW were constructed.
• Linear equations were derived to calculate fetal weight using BPD, AC, and FL with FW as the independent variable.

Conclusions:

• The developed first-trimester centile charts serve as a valuable reference for the Indian population.
• These charts can assist in accurate determination of gestational age.
• The charts are useful for identifying potential adverse pregnancy outcomes.