Low-Lying Placenta and Pregnancy Outcomes in a Large National Cohort [ID 2683532

Abstract

INTRODUCTION: We sought to understand the association of low-lying placenta and adverse pregnancy outcomes among those undergoing cesarean delivery. METHODS: This was a retrospective cohort study of persons undergoing cesarean delivery using the National Inpatient Sample from 2017 to 2019 through HCUP/AHRQ. Patients with placenta previa were excluded. Rates of adverse maternal outcomes were compared between patients undergoing cesaeran delivery with ICD-10 codes of low-lying placenta and those without. The outcomes included were preterm delivery, hemorrhage, hysterectomy, placenta accreta spectrum (PAS), sepsis, shock, disseminated intravascular coagulation (DIC), and transfusion. Groups were compared using ANOVA, chi-squared analysis, logistic and linear regressions to control for confounders. RESULTS: Over 700,000 participants underwent cesarean delivery. 2,664 (0.4%) had low-lying placenta. Affected patients were older, more likely to be anemic, privately insured, undergoing primary cesarean, and deliver at a large/urban teaching hospital. Those with low-lying placenta were more likely to deliver preterm (31.9% versus 14.3%), hemorrhage (27.8% versus 3.8%), undergo hysterectomy (2.0% versus 0.2%), have PAS (2.4% versus 0.2%), receive transfusion (5.4% versus 2.0%) (all P<.001), and experience sepsis, shock, and DIC (all P<.05). Many of these findings persisted after controlling for confounders—preterm delivery (adjusted odds ratio [aOR] 3.07; 95% CI, 2.81–3.35), hemorrhage (aOR 8.87; 95% CI, 8.10–9.73), hysterectomy (aOR 9.42; 95% CI, 7.11–12.47), PAS (aOR 13.41; 95% CI, 10.34–17.39), transfusion (aOR 2.56; 95% CI, 2.14–3.06), and shock (aOR 2.55; 95% CI, 1.44–4.52). CONCLUSION: Low-lying placenta at time of cesarean is associated with adverse outcomes and should be considered in counseling and delivery planning.