Ultrasonographic Measurement of the Fetal Foot Length and the Ratio of the Fetal Femur to Foot Length to Determine the Fetal Gestational Age.

BACKGROUND

Accurate estimation of fetal gestational age (GA) is critical for optimal prenatal care. Fetal foot length (FFL) has emerged as a promising alternative due to its relatively stable growth pattern throughout gestation. Additionally, the femur-to-foot length (FL/FFL) ratio has been proposed as a method to enhance GA estimation accuracy.

AIM

This study aimed to assess relationship between sonographic GA and FFL.

MATERIALS AND METHODS

A prospective observational study was conducted in the Department of Radiology at Aarupadai Veedu Medical College and Hospital, Puducherry. A total of 90 antenatal women with singleton pregnancies between 16 and 34 weeks of gestation were included. FFL and femur length were measured using a Mindray DC 80 ultrasound scanner. Pearson correlation analysis and independent -tests were performed using SPSS version 26.0, (IBM Corp., Armonk, NY) with significance set at < .05.

RESULTS

GA corresponded with ultrasound findings in 93.3% of participants. A strong positive correlation was observed between GA and FFL ( = 0.899, < .001). Additionally, FFL correlated significantly with BPD ( = 0.915), HC ( = 0.918), AC ( = 0.914), and FL ( = 0.955) ( < .001 for all). The FL/FFL ratio remained stable mean value of 1.0132, reinforcing its reliability as a supplementary marker.

CONCLUSION

Fetal foot length is a reliable marker for GA estimation and exhibits strong correlations with other biometric indices. The stable FL/FFL ratio further supports its use as a supplementary parameter in assessing fetal growth.