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Abstract

We appreciate Brennan and Robson's interest in our study. Their 10-group classification of cesarean delivery (CD) is another method of risk stratification, which has a goal of creating homogeneous risk groups from which to make comparisons. We acknowledge 1 benefit of such a system over the nulliparous term singleton singleton vertex (NTSV) system is that it does not ignore potentially large groups of women such as multipara. While we were aware of this method,1Fischer A. LaCoursiere D.Y. Barnard P. Bloebaum L. Varner M. Differences between hospitals in cesarean rates for term primigravidas with cephalic presentation.Obstet Gynecol. 2005; 105: 816-821Crossref PubMed Scopus (20) Google Scholar we did not use this system, in part because it has not been proposed as a quality measure in the United States, and also because the data source for such classification, birth certificates, does not include information used to classify women into some of the 10 groups, such as cesarean delivery, before labor and oblique or transverse lie. One important point of classification, induction of labor, was available to us and was found in our multivariable analysis to be a significant risk factor predictive of CD rates. This suggests that some stratification by this variable should be performed. This could be done either by calculating rates in those with spontaneous labor separate from those induced, as is done in the Robson approach,2Robson M. Classification of caesarean sections.Fetal and Maternal Medicine Review. 2001; 12: 23-39Crossref Scopus (295) Google Scholar or through statistical adjustment. We do note, however, that some important variables that influenced CD rates in our multivariable analysis are not accounted for in the Robson classification system, such as age, gestational age, and complications such as preeclampsia. This suggests that whether creating 1 group, as with the NTSV approach, or 10 groups, as with the Robson approach, not as much homogeneity may be produced as desired. Therefore, adjusting for risk factors may still be necessary—1 of the conclusions of our study. Nulliparous term singleton vertex caesarean delivery ratesAmerican Journal of Obstetrics & GynecologyVol. 200Issue 5PreviewWe agree with Coonrod et al1 that studying the nulliparous term singleton vertex (NTSV) cesarean delivery (CD) rates across a range of institutions can be useful in explaining the variation in overall CD rates. Full-Text PDF