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Am J Perinatol 2024; 41(S 01): e1001-e1007
DOI: 10.1055/s-0042-1759721
Original Article

The Risk of Neonatal Morbidity in Umbilical Artery Hypercarbia and Respiratory Acidosis

Drew Hensel
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
,
Leilah Zahedi-Spung 
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
,
Ebony B. Carter
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
,
Alison G. Cahill
2   Department of Women's Health, The University of Texas at Austin Dell Medical School, Austin, Texas
,
Nandini Raghuraman
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
,
Joshua I. Rosenbloom 
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
3   Faculty of Medicine, Department of Obstetrics and Gynecology, Hadassah Medical Organization, The Hebrew University of Jerusalem, Jerusalem, Israel
› Author Affiliations Financial Support A.G.C. is supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD061619-01, PI Cahill) and was a Robert Wood Johnson Foundation Faculty Physician Scholar, which partially supported this work. This publication was also made possible by grant number UL1 TR000448 from the NIH National Center for Advancing Translational Sciences (NCATS), components of the National Institutes of Health (NIH), and NIH Roadmap for Medical Research.
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Abstract

Objective To test the hypothesis that elevated umbilical artery (UA) partial pressure of carbon dioxide (pCO2) is associated with neonatal morbidity and to compare the risk of neonatal morbidity with different patterns of UA acidosis.

Study Design This was a secondary analysis of a prospective cohort of term, singleton, nonanomalous deliveries with universal cord gas collection. The primary outcome was composite neonatal morbidity. Multivariable logistic regression was used to determine the relative risk (RR) for neonatal morbidity in patients with and without UA hypercarbia. A receiver operating characteristic curve determined the predictive value of pCO2 for neonatal morbidity. An additional multivariable logistic regression was used to evaluate the risk of neonatal morbidity in different patterns of UA acidosis.

Results UA hypercarbia was associated with an increased risk of neonatal morbidity (RR: 2.56, 95% confidence interval [CI]: [2.07, 3.17]). After adjusting for UA acidemia, this association remained significant (adjusted RR: 1.39, 95% CI: [1.05, 1.83]). UA pCO2 was less predictive of neonatal morbidity than UA pH (area under the curve [AUC]: 0.65, 95% CI: [0.62, 0.68] vs. AUC: 0.72, 95% CI: [0.69, 0.75], p < 0.01). The odds ratios for neonatal morbidity for respiratory, mixed, and metabolic acidosis compared with normal cord gases were 1.48 (95% CI: [0.88, 2.49]), 6.41 (95% CI: [3.68, 11.17]), and 7.49 (95% CI: [5.76, 9.72]), respectively, p-trend < 0.01.

Conclusion UA hypercarbia is an independent predictor of neonatal morbidity, even in the setting of concomitant UA acidemia. UA mixed and metabolic acidosis carry significantly greater risk of neonatal morbidity compared with respiratory acidosis.

Key Points

  • UA pCO2 is associated with neonatal morbidity.

  • UA respiratory acidosis is the UA cord gas pattern least associated with neonatal morbidity.

  • UA pH is a superior predictor of neonatal morbidity compared with UA pCO2.

Keywords

umbilical artery hypercarbia - umbilical artery respiratory acidosis - neonatal morbidity


Publication History

Received: 19 July 2021

Accepted: 01 November 2022

Article published online:
21 December 2022

© 2022. Thieme. All rights reserved.

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