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
Cite this paper
Wah, Y. , Chan, Y. , Sahota, D. , Hui, S. , Lau, T. and Leung, T. (2014) Intra- and Inter-Observer Reproducibility of Ultrasound Measurements of Pelvic Inlet Diameter in Pregnant Women. Open Journal of Obstetrics and Gynecology
, 653-658. doi: 10.4236/ojog.2014.411091
 Stewart, K.S. and Philpott, R.H. (1980) Fetal Response to Cephalopelvic Disproportion. BJOG: An International Jour- nal of Obstetrics & Gynaecology, 87, 641-649.
 Pattinson, R.C. (2000) Pelvimetry of Fetal Cephalic Presentations at or Near Term. Cochrane Database of Systematic Reviews, 2, Article ID: CD000161.
 Sporri, S., Hanggi, W., Braghetti, A., Vock, P. and Schneider, H. (1997) Pelvimetry by Magnetic Resonance Imaging as a Diagnostic Tool to Evaluate Dystosia. Obstetrics Gynecology, 89, 902-908.
 Van Loon, A.J., Mantingh, A., Serlier, E.K., Kroon, G., Mooyaart, E.L. and Huisjes, H.J. (1997) Randomised Controlled Trial of Magnetic-Resonance Pelvimetry in Breech Presentation at Term. Lancet, 350, 1799-1804.
 Bartlett, J.W. and Frost, C. (2008) Reliability, Repeatability and Reproducibility: Analysis of Measurement Errors in Continuous Variables. Ultrasound in Obstetrics Gynecology, 31, 466-475. http://dx.doi.org/10.1002/uog.5256
 Bland, J.M. and Altman, D.G. (2003) Applying the Right Statistics: Analyses of Measurement Studies. Ultrasound in Obstetrics Gynecology, 22, 85-93. http://dx.doi.org/10.1002/uog.122
 Keller, T.M., Rake, A., Michel, S.C., Seifert, B., Efe, G., Treiber, K., Huch, R., Marincek, B. and Kubik-Huch, R.A. (2003) Obstetric MR Pelvimetry: Reference Values and Evaluation of Inter- and Intraobserver Error and Intraindividual Variability. Radiology, 227, 37-43. http://dx.doi.org/10.1148/radiol.2271011658
 Katanozaka, M., Yoshinaga, M., Fuchiwaki, K. and Nagata, Y. (1999) Measurement of Obstetric Conjugate by Ultrasonic Tomography and Its Significance. American Journal of Obstetrics Gynecology, 180, 159-162.
 Korhonen, U., Solja, R., Laitinen, J., Heinonen, S. and Taipale, P. (2010) MR Pelvimetry Measurements, Analysis of Inter- and Intra-Observer Variation. European Journal of Radiology, 75, 56-61.
 Huerta-Enochian, G.S., Katz, V.L., Fox, L.K., Hamlin, J.A. and Kollath, J.P. (2006) Magnetic Resonance-Based Serial Pelvimetry: Do Maternal Pelvic Dimensions Change during Pregnancy? American Journal of Obstetrics Gynecology, 194, 1689-1695. http://dx.doi.org/10.1016/j.ajog.2006.03.008