First-trimester fetal limb biometry in Chinese population.

Area of Science:

• Prenatal diagnostics
• Fetal biometry
• Medical imaging

Background:

• Accurate fetal biometry is crucial for monitoring pregnancy progression.
• Establishing gestational age-specific reference ranges aids in identifying potential fetal abnormalities.
• Transabdominal ultrasound is a standard imaging modality in prenatal care.

Purpose of the Study:

• To determine reference ranges for fetal limb biometry (humerus and femur length) using transabdominal ultrasound.
• To provide normative data for fetuses of Chinese women between 12 and 14 weeks of gestation.
• To assess the utility of fetal limb length in early detection of growth disorders and skeletal dysplasias.

Main Methods:

• A prospective study involving 1489 normal singleton fetuses.
• Transabdominal ultrasound examinations were performed by experienced observers.
• Fetal gestation was confirmed using crown-rump length (CRL) or biparietal diameter (BPD) and head circumference (HC).
• Femur length (FL) and humerus length (HL) were measured.

Main Results:

• Gestation-specific reference ranges for fetal femur and humerus lengths were calculated.
• At 12-14 weeks gestation, mean femur length ranged from 9.15 mm to 13.64 mm.
• At 12-14 weeks gestation, mean humerus length ranged from 9.63 mm to 14.29 mm.
• A consistent increase in limb lengths with advancing gestation was observed.

Conclusions:

• Fetal limb biometry demonstrates a clear increase with gestational age.
• Fetal limb length measurements can serve as an early indicator for fetal growth restriction.
• These reference ranges are valuable for identifying skeletal dysplasias in the early stages of pregnancy.