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Am J Perinatol 2024; 41(S 01): e2403-e2409
DOI: 10.1055/a-2113-2892
Original Article

Associations between Anemia and Outcomes of Pregnant Patients with Pyelonephritis

Hannah M. Cunningham
1   Department of Obstetrics and Gynecology, Yale University, New Haven, Connecticut
,
Hope E. Knochenhauer 
2   Department of Obstetrics and Gynecology, Staten Island University, Staten Island, New York
,
Jerome J. Federspiel 
3   Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, North Carolina
,
Lauren E. Wein
2   Department of Obstetrics and Gynecology, Staten Island University, Staten Island, New York
,
Anna E. Denoble 
1   Department of Obstetrics and Gynecology, Yale University, New Haven, Connecticut
,
R. Phillips Heine
4   Department of Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, North Carolina
,
Sarah K. Dotters-Katz
3   Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, North Carolina
› Author Affiliations Funding This research was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health under award number TL1TR002555. This funding provided Dr. Federspiel's effort for this study. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Data acquisition was also supported by funding from the Foundation for Women and Girls with Blood Disorders to J.J.F.
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Abstract

Objective This study aims to determine if pregnant patients with both pyelonephritis and anemia are at an increased risk of adverse maternal outcomes compared with those with pyelonephritis without anemia.

Study Design We conducted a retrospective cohort study utilizing the Nationwide Readmissions Database (NRD). Patients with antepartum pyelonephritis-associated hospitalizations from October 2015 to December 2018 were included. International Classification of Diseases codes were used to identify pyelonephritis, anemia, maternal comorbidities, and severe maternal morbidities. The primary outcome was a composite of severe maternal morbidity, as defined by the Centers for Disease Control criteria. Univariate statistical methods, weighted to account for complex survey methods in the NRD, were used to assess for associations between anemia, baseline characteristics, and patient outcomes. Weighted logistic and Poisson regressions were used to assess for associations between anemia and outcomes, adjusting for clinical comorbidities and other confounding factors.

Results In total, 29,296 pyelonephritis admissions were identified, corresponding to a weighted national estimate of 55,135 admissions. Of these, 11,798 (21.3%) were anemic. The rate of severe maternal morbidity was higher among anemic patients than nonanemic patients (27.8 vs. 8.9%, respectively, p < 0.001), and remained higher after adjustment (adjusted relative risk [aRR] 2.86 [95% confidence interval [CI]: 2.67, 3.06]). Rates of individual components of severe maternal morbidities, including acute respiratory distress syndrome (4.0 vs. 0.6%, aRR 3.97 [95% CI: 3.10, 5.08]), sepsis (22.5 vs. 7.9%, aRR 2.64 [95% CI: 2.45, 2.85]), shock (4.5 vs. 0.6%, aRR 5.48 [95% CI: 4.32, 6.95]), and acute renal failure (2.9 vs. 0.8%, aRR 1.99 [95% CI: 1.55, 2.55]) were all higher for anemic pyelonephritis. The mean length of stay was also longer (25% average increase, 95% CI: 22, 28%).

Conclusion Among pregnant patients with pyelonephritis, those with anemia are at greater risk of severe maternal morbidity and longer hospital stay.

Key Points

  • Anemia is associated with longer stays for pyelo.

  • Anemic pyelo patients have increased morbidity.

  • Anemic pyelo patients have increased sepsis risk.

Keywords

anemia - maternal morbidity - pregnancy - pyelonephritis

Supplementary Material



Publication History

Received: 13 December 2021

Accepted: 19 June 2023

Accepted Manuscript online:
20 June 2023

Article published online:
20 July 2023

© 2023. Thieme. All rights reserved.

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