TITLE:
Intra- and Inter-Observer Reproducibility of Ultrasound Measurements of Pelvic Inlet Diameter in Pregnant Women
AUTHORS:
Yi Man Wah, Yiu Man Chan, Daljit Singh Sahota, Shuk Yi Hui, Tze Kin Lau, Tak Yeung Leung
KEYWORDS:
Pelvimetry, Pelvic Inlet Diameter, Obstetric Conjugate
JOURNAL NAME:
Open Journal of Obstetrics and Gynecology,
Vol.4 No.11,
August
15,
2014
ABSTRACT: Objectives: To determine
intra- and inter-observer reproducibility of the ultrasound measurement of
pelvic inlet in the first trimester of pregnancy. Methods: Transabdominal
pelvic ultrasound was performed to measure the pelvic inlet anteroposterior
diameter using a 2D probe in twelve Chinese women having a singleton pregnancy.
Scans were performed in the first trimester by three sonographers. The pelvic
inlet anteroposterior diameter was defined as the distance between the anterior
surfaces of the sacral promontory and the superior medial border of the pubic
bone most adjacent to the pubic symphysis. Intra-observer repeatability was
determined and analysis of variance was performed to assess inter-observer
measurements. The bias between any two sonographers’ measurements was assessed
by calculating the 95% confidence interval for the mean difference between
sonographers paired measurements. Results: Intra-observer reproducibility was
0.71 cm. Analysis of variance indicated that there was no significant
difference between sonographers’ measurements (p = 0.46). The bias between two
sonographers’ measurements ranged from 0.05 to 0.32 cm. Conclusion: It is
technically feasible to measure the pelvic inlet diameter using ultrasound
(USG) at the first trimester. High inter-observer reproducibility can be
achieved. Further studies are required to establish the potential role of this
technique and the measurement of the pelvic inlet diameter in prediction of
labor outcome.