Relationship between fetal bi-iliac distance with fetomaternal characteristics and fetal growth indexes at second trimester of pregnancy

Abstract

One of the essential uses of ultrasound examination in women is to evaluate the growth of the fetus by confirming the gestational age; So that failure to identify fetal growth abnormalities can be associated with high morbidity and mortality, and identifying these problems is also very important. The aim of the current study is to investigate the relationship between the distance between the iliac wings with maternal-fetal characteristics and fetal growth indicators in the second trimester of pregnancy. Materials and Methods: In this cross-sectional study during 12 months, the relationship of Bi-iliac Distance with some maternal-fetal characteristics (maternal age, gestational age and fetal weight) and fetal growth indices (BPD-HC-AC-FH) in The second trimester of pregnancy (14-25 weeks) was evaluated. For this purpose, fetal ultrasound was performed for pregnant mothers who are in the second trimester of pregnancy and had a normal screening ultrasound in the first trimester and now referred for a second trimester screening ultrasound. Results: In this cross-sectional study, 330 pregnant women with an average age of 29.99±5.85 years and an average gestational age of 19.43 W + 2.43 D were evaluated. 65.2% of fetuses were female. All pregnancies were normal in terms of screening in the first and second trimesters. The average values of BPD, FL, HC, and AC in the current study were 44.99 ± 12.38 mm, 32.26 ± 15.92 mm, 169.31 ± 44.92 mm, and 146.46 ± 39.50 mm, respectively. The measurement and comparison of the Bi-Iliac distance in terms of the sex of the fetus did not show a statistically significant difference between the two sexes in the axial and coronal planes (p>0.05). On the contrary, a direct and significant correlation was observed between Bi-Iliac distance and gestational age based on CRL. The highest correlation was observed in the superior coronal plane (r=0.991) and the lowest in the posterior axial plane (r=0.967). Bi-iliac distance in the examined fetuses in the current study had a significant and direct correlation with biometric findings and estimated fetal weight, but the correlation between bi-iliac distance and FL was lower than other indicators.