evaluation of the relationship between fetal lung to head ratio and amniotic fluid index in the third trimester of pregnancy

Background objective: this study assessed the relationship between the ratio of fetal lung volume to head circumference and amniotic fluid index (afi) in the third trimester of pregnancy.materials methods: this prospective study was performed on low-risk pregnant women in their third trimester of pregnancy. fetal lung volume was determined separately using the lung-to-head ratio (lhr) for the right and left lungs. moreover, the afi was evaluated, and the pearson correlation coefficient between lhr for both lungs and afi was investigated.results: overall, 112 pregnant women were included in the study. the mean ± standard deviation (sd) of fetal observed/expected right lhr (o/e rlhr) and o/e left lhr (o/e llhr) were 113.9±0.36 and 97.13±27.87, respectively. the mean ± sd of afi was 12.5±4.96 cm. pearson correlation coefficient did not show a significant relationship between afi and the left and right lhr (p < /em>>0.05). however, o/e rlhr was significantly correlated with abdominal circumference (p < /em>=0.02, r=0.2), gestational age (p < /em>=0.21, r=0.27), and fetal weight (p < /em><0.001, r=0.27). there was a positive correlation between the number of days the infant was admitted to the neonatal intensive care unit and the volume of the right lung of the fetus (p < /em>=0.03, r=-0.2). no correlation was observed between fetal parameters and the volume of the left lung of the fetus.conclusion: the results of this study showed that afi in the third trimester of pregnancy was not significantly correlated with lhr.