Evaluation of role of femur length / mid thigh circumference ratio in differentiation between small for gestational age but healthy fetuses and intrauterine growth restricted fetuses

Abstract

The current study has proposed the sonograghic measurements of fetal mid-thigh soft tissue circumference (MTC) in relation to femur length (FL) as a possible parameter for assessment of fetal growth. The aim of this study was to evaluate the accuracy and usefulness of measuring femur length to mid-thigh circumference ratio in differentiation between small for gestational age but healthy fetuses (SGA) and intrauterine growth restricted fetuses (IUGR) by ultrasound. The study was conducted at Ain Shams University Maternity Hospital during the period between 1st of June 2015 and 31st of May 2016, 89 pregnant ladies in third trimester were included in the study. All fetal measurements were obtained from 2D data set for the following parameters: biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), mid-thigh circumference (MTC), estimated fetal weight (EFW), amniotic fluid index (AFI), umbilical artery Doppler, middle cerebral artery Doppler (MCA Doppler) and FL/MTC ratio Regarding patients characteristics, the study showed that there was no statistical significance between both groups regarding age, body mass index or blood pressure Regarding parity, the study showed that the incidence of SGA but healthy fetuses is more in PG (45.5% vs. 11.8%) (P <0.001) Regarding fetal biometric features, the study showed that FL/MTC ratio can not differentiate between both groups (P>0.05) Also, the study showed there is statistical significant difference between both groups regarding BPD, HC and FL, being bigger in SGA group than IUGR group, with sensitivity of 61.8%, 61.8% and 47.1% respectively, and specificity 76.4%, 89.1% and 98.2% respectively. The study showed that AFI was a good parameter to differentiate between SGA but healthy fetuses and IUGR fetuses with cut off value equal to≤ 5 (P <0.0001)(sensitivity 97.1% and specificity 89.1%), AU