American Journal of Obstetrics & Gynecology
Volume 200, Issue 3 , Pages 340.e1-340.e3, March 2009

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.

  • Sean C. Blackwell, MD

      Affiliations

    • Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, TX
    • ,
  • Jerrie Refuerzo, MD

      Affiliations

    • Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, TX
    • ,
  • Rati Chadha, MD

      Affiliations

    • Foothills Medical Center, University of Calgary, Calgary, AB, Canada
    • ,
  • Carlos A. Carreno, MD

      Affiliations

    • Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, TX

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.

Key words: estimated fetal weight, labor induction, nulliparity, ultrasound

 

 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.

 Reprints not available from the authors.

PII: S0002-9378(08)02449-6

doi:10.1016/j.ajog.2008.12.043

American Journal of Obstetrics & Gynecology
Volume 200, Issue 3 , Pages 340.e1-340.e3, March 2009