Overestimation of fetal weight by ultrasound: does it influence the likelihood of cesarean delivery for labor arrest?
Presented at the 75th Annual Meeting of the Central Association of Obstetricians and Gynecologists, New Orleans, LA, Oct. 22-25, 2008.
Received 29 July 2008; received in revised form 15 November 2008; accepted 22 December 2008.
Objective
We sought to determine whether the overestimation of ultrasound-derived estimated fetal weight (EFW) is associated with increased diagnosis of labor arrest.
Study Design
This is a historical cohort study of nulliparous women with term pregnancies who underwent bedside ultrasound examination for EFW before labor induction. Labor outcomes of women with EFW overestimation > 15% the actual birthweight were compared with those with EFW not overestimated.
Results
Overestimation of EFW occurred in 9.5% of cases (23/241). The rate of cesarean delivery (CD) for labor arrest was higher for those with EFW overestimation (34.8% vs 13.3%; P = .01) even though there were no differences in length of the induction duration. After adjusting for confounding factors, EFW overestimation remained associated with CD for labor arrest (odds ratio, 4.8; 95% confidence interval, 1.5-15.2).
Conclusion
Our finding suggests that an overestimation of EFW may be associated with a lower threshold for CD for labor arrest.
aDivision of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, TX
bFoothills Medical Center, University of Calgary, Calgary, AB, Canada
Cite this article as: Blackwell SC, Refuerzo J, Chadha R, et al. Overestimation of fetal weight by ultrasound: does it influence the likelihood of cesarean delivery for labor arrest? Am J Obstet Gynecol 2009;200:340.e1-340.e3.
ABSTRACT
Overestimation of fetal weight by ultrasound: does it influence the likelihood of cesarean delivery for labor arrest?