Cesarean delivery for fetal distress: rate and risk factors

The objective of this article was to review the recent English language literature on cesarean delivery for fetal distress to determine its incidence, diagnostic tests, and the contributing factors to this obstetric complications. A PubMed search (1990-2000) with items of "cesarean, fetal distress," "cesarean, non-reassuring fetal heart rate," "cesarean, neonatal acidosis," and "cesarean, umbilical arterial pH," was undertaken. Reports, letters to the editor, focus on anomalous fetuses, and papers not specifically focused on this topic were excluded. Of the 392 articles that the search yielded, 169 met the inclusion criteria. Based on 37 reports with more than 1,000 patients each, the overall risk of prompt cesarean delivery for fetal concern was 3.1% (43,340 of 13,989,74). The risk exceeded 20% in patients with moderate/severe asthma, severe hypothyroidism, severe preeclampsia, and postterm or fetal growth restricted fetuses with abnormal Doppler studies. Use of likelihood ratios suggests that Doppler of the umbilical artery is a superior diagnostic test to amniotic fluid index in identifying parturients at risk for cesarean for non-reassuring fetal heart rate tracing. Although several risk factors increase the need for cesarean delivery for fetal distress, in general, most are unpreventable. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to estimate the incidence of cesarean delivery for non-reassuring fetal heart rate tracing, outline potential diagnostic tests that are useful for the detection of fetal distress, and summarize medical and obstetric conditions that place patients at risk for cesarean delivery for fetal distress.