Measurement of Neonatal Foot Length to Indentify Preterm Babies: A Cross Sectional Hospital Based Study

Objective: To find out the correlation between Gestational age and foot length and identify a cut off value of neonatal foot length for identifying preterm babies that can be used by peripheral health care workers for timely referral of preterm and low birth weight newborns.

Methodology: This was a cross sectional observational study done at Government Multi Specialty Hospital, Sector-16, Chandigarh, India. A total of 192 newborns were enrolled and examined within 24 to 36 hours of birth. Babies with congenital deformities, syndromic and babies with foot edema were excluded from the study.

Result: Using Youden’s index, the critical cut off point of foot length was found to be 7.65 cm, foot length below 7.65 cm can diagnose preterm babies with sensitivity of 87.3%, specificity of 87.6% and Area Under Curve (AUC) of 0.930, (P = 0.0001). Foot length was found to have positive correlation with gestational age estimation by New Ballard’s Score (r = 0.735) as compared to Last Menstrual Period (r = 0.440) and Ultrasonography (r = 0.347). Foot length below 7.65 cm can distinguish low birth weight babies with sensitivity of 76.2%, specificity of 74% and AUC of 0.847.

Conclusion:

1. Foot length is a simple, effective and easy to use tool to identify preterm and low birth weight babies by peripheral health workers in community settings.

2. Foot length of 7.65 cm can be used as a cutoff point for differentiating between preterm and term babies; low birth weight and normal birth weight babies.