Prior cesarean and the risk for placenta previa on second-trimester ultrasonography.

Published

Journal Article

OBJECTIVE: To determine whether the increased risk of placenta previa at delivery in patients with a prior cesarean results from an increased risk of abnormal implantation or a lower likelihood of resolution. METHODS: A hospital-based, case-control study was performed. Cases were defined as singleton pregnancies with a placenta previa on second-trimester ultrasonography. Controls, chosen randomly from patients without a placenta previa on second-trimester ultrasonography, were matched 3:1 with cases. Odds ratios (OR) were calculated, controlling for other independent risk factors for previa: age, parity, race, and smoking. RESULTS: There were 88 cases identified and 264 controls. Twenty cases (22.7%) and 35 controls (13.3%) had a history of prior cesarean delivery. Previous cesarean delivery was an independent risk factor for previa on second-trimester ultrasonography (OR 1.92, 95% confidence interval [CI] 1.04-3.55), as was the number of cesareans (OR 1.62, 95% CI 1.12-2.34). However, neither retained their significance after adjusting for other known risk factors for previa (OR 1.50, 95% CI 0.77-2.92, and OR 1.40, 95% CI 0.93-2.10, respectively). At delivery, a history of cesarean was associated with a 3-fold increased risk of previa. CONCLUSION: A previous cesarean delivery did not increase the odds for detecting a placenta previa on second-trimester ultrasonography. At delivery, a previous cesarean was associated with a previa, suggesting a lower likelihood of resolution.

Full Text

Duke Authors

Cited Authors

  • Laughon, SK; Wolfe, HM; Visco, AG

Published Date

  • May 2005

Published In

Volume / Issue

  • 105 / 5 Pt 1

Start / End Page

  • 962 - 965

PubMed ID

  • 15863531

Pubmed Central ID

  • 15863531

Electronic International Standard Serial Number (EISSN)

  • 1873-233X

International Standard Serial Number (ISSN)

  • 0029-7844

Digital Object Identifier (DOI)

  • 10.1097/01.aog.0000158114.47925.fa

Language

  • eng