Impact of maternal weight on the intra‐observer and inter‐observer reproducibility of fetal ultrasonography measurements in the third trimester

Abstract

Objective: To evaluate the effect of maternal weight on the intra-and inter-observer reproducibility of third-trimester ultrasonography fetal measurements. Methods:The present prospective study, performed at a tertiary hospital, enrolled patients at between 35 +0 weeks and 36 +6 weeks of singleton pregnancies between January 1, 2015, and July 1, 2016. Fetal ultrasonography measurements were evaluated twice by a first observer and a third time by a second observer. Intra-and interobserver consistency were analyzed using the Cronbach α reliability coefficient, and measurement reproducibility was compared with patients stratified by a body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters) of below 25 or at least 25. Results:The study included 197 patients (133 with BMI <25 and 64 with BMI ≥25).Among patients with a BMI below 25, the reliability coefficients for bi-parietal diameter, head circumference, abdominal circumference, and femur length measurements were 0.97, 0.95, 0.98, and 0.96, respectively, for intra-observer consistency, and were 0.97, 0.93, 0.98, and 0.95, respectively, for inter-observer consistency. Among patients with a BMI of at least 25, these values were 0. 97, 0.96, 0.98, and 0.97, respectively, for intra-observed consistency, and 0.97, 0.94, 0.98, and 0.96, respectively, for inter-observer consistency. Conclusion:High intra-and inter-observer reproducibility was observed for third-trimester fetal ultrasonography measurements, including for patients who were overweight. K E Y W O R D SFetal biometry; Intra-and inter-observer reproducibility; Obesity; Third trimester ultrasound

Influence of maternal body mass index on interobserver variability of fetal ultrasound biometry and amniotic‐fluid assessment in late pregnancy

“…The findings of our study demonstrate that all fetal biometric measurements are highly reproducible between different observers, both in women with a normal BMI and in those with an increased BMI in the third trimester, reflected in the high overall ICCs and CRCs. Our results are similar to those of previous studies that evaluated interobserver variability of fetal biometric measurements 2,13,14 . However, our study additionally provides information, using modern ultrasound equipment, on ICC values in subclasses of pregnancies of obese women.…”

“…In this study, we evaluated the interobserver reproducibility of sonographic fetal biometric and amniotic-fluid measurements in the third trimester, as this is the gestational-age period in which growth assessment is most likely to influence clinical decisions regarding timing and mode of delivery 2,5 . Given the high prevalence of obesity, which is associated with adverse pregnancy outcome and often leads to suboptimal ultrasound visualization 13,29 , our aim was to evaluate the reproducibility of these measurements in this population.…”

“…third trimester included overweight and obese women in the same group, but only 10% of the women were obese and there was no stratification according to BMI category 13 . When the ICC and CRC of fetal biometric measurements were compared between normal and increased-BMI groups, only BPD showed excellent reproducibility across all groups (Table 3).…”

“…Many previous studies examining the reproducibility of fetal biometric ultrasound measurements have been limited by small and heterogeneous populations 7 , a narrow range of gestational age 7,8 , use of outdated ultrasound equipment 9 , a limited number of biometric indices examined 9,10 and varied skill levels of the sonographers performing the examinations 7,[9][10][11][12][13][14] . In a large prospective longitudinal study performed in low-risk pregnancies under standardized conditions, intra-and interobserver variability in fetal biometric measurements throughout pregnancy were evaluated 2 .…”

Maternal hemodynamics in screen‐positive and screen‐negative women of the ASPRE trial

“…Current efforts to create a prediction model to identify FGR and those at risk of operative delivery for fetal compromise in SGA fetuses at term could be improved by incorporating maternal PE screening status and hemodynamic examinations. Given the inherent error of third‐trimester fetal biometry measurements, repeated maternal hemodynamic measures using a non‐operator‐dependent technique in the third trimester could potentially risk‐stratify screen‐positive pregnancies to guide timing of induction of labor if SGA is suspected.…”