Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Adverse neonatal outcome and veno-arterial differences in umbilical cord blood pH (ΔpH) at birth : a population-based study of 108,629 newborns

Sundberg, Tiia-Marie LU orcid ; Wiberg, Nana LU orcid ; Källén, Karin LU and Zaigham, Mehreen LU orcid (2023) In BMC Pregnancy and Childbirth 23. p.1-9
Abstract

BACKGROUND: Umbilical cord blood gases are routinely used by midwives and obstetricians for quality assurance of birth management and in clinical research. They can form the basis for solving medicolegal issues in the identification of severe intrapartum hypoxia at birth. However, the scientific value of veno-arterial differences in cord blood pH, also known as ΔpH, is largely unknown. By tradition, the Apgar score is frequently used to predict perinatal morbidity and mortality, however significant inter-observer and regional variations decrease its reliability and there is a need to identify more accurate markers of perinatal asphyxia. The aim of our study was to investigate the association of small and large veno-arterial differences... (More)

BACKGROUND: Umbilical cord blood gases are routinely used by midwives and obstetricians for quality assurance of birth management and in clinical research. They can form the basis for solving medicolegal issues in the identification of severe intrapartum hypoxia at birth. However, the scientific value of veno-arterial differences in cord blood pH, also known as ΔpH, is largely unknown. By tradition, the Apgar score is frequently used to predict perinatal morbidity and mortality, however significant inter-observer and regional variations decrease its reliability and there is a need to identify more accurate markers of perinatal asphyxia. The aim of our study was to investigate the association of small and large veno-arterial differences in umbilical cord pH, ΔpH, with adverse neonatal outcome.

METHODS: This retrospective, population-based study collected obstetric and neonatal data from women giving birth in nine maternity units from Southern Sweden from 1995 to 2015. Data was extracted from the Perinatal South Revision Register, a quality regional health database. Newborns at ≥37 gestational weeks with a complete and validated set of umbilical cord blood samples from both cord artery and vein were included. Outcome measures included: ΔpH percentiles, 'Small ΔpH' (10th percentile), 'Large ΔpH' (90th percentile), Apgar score (0-6), need for continuous positive airway pressure (CPAP) and admission to neonatal intensive care unit (NICU). Relative risks (RR) were calculated with modified Poisson regression model.

RESULTS: The study population comprised of 108,629 newborns with complete and validated data. Mean and median ΔpH was 0.08 ± 0.05. Analyses of RR showed that 'Large ΔpH' was associated with a decreased RR of adverse perinatal outcome with increasing UApH (at UApH ≥7.20: RR for low Apgar 0.29, P = 0.01; CPAP 0.55, P = 0.02; NICU admission 0.81, P = 0.01). 'Small ΔpH' was associated with an increased RR for low Apgar score and NICU admission only at higher UApH values (at UApH 7.15-7.199: RR for low Apgar 1.96, P = 0.01; at UApH ≥7.20: RR for low Apgar 1.65, P = 0.00, RR for NICU admission 1.13, P = 0.01).

CONCLUSION: Large differences between cord venous and arterial pH (ΔpH) at birth were associated with a lower risk for perinatal morbidity including low 5-minute Apgar Score, the need for continuous positive airway pressure and NICU admission when UApH was above 7.15. Clinically, ΔpH may be a useful tool in the assessment of the newborn's metabolic condition at birth. Our findings may stem from the ability of the placenta to adequately replenish acid-base balance in fetal blood. 'Large ΔpH' may therefore be a marker of effective gas exchange in the placenta during birth.

(Less)
Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Pregnancy, Humans, Infant, Newborn, Female, Fetal Blood, Retrospective Studies, Proton-Motive Force, Reproducibility of Results, Arteries, Infant, Newborn, Diseases, Hydrogen-Ion Concentration, Apgar Score
in
BMC Pregnancy and Childbirth
volume
23
article number
162
pages
1 - 9
publisher
BioMed Central (BMC)
external identifiers
  • scopus:85149904468
  • pmid:36906543
ISSN
1471-2393
DOI
10.1186/s12884-023-05487-8
project
Use of Umbilical Cord Blood Gases in Determining Mortality and Morbidity after Birth Asphyxia
language
English
LU publication?
yes
additional info
© 2023. The Author(s).
id
7d54dc8e-a26e-49bd-8023-e211cdc14087
date added to LUP
2023-03-18 12:46:22
date last changed
2024-06-29 02:47:19
@article{7d54dc8e-a26e-49bd-8023-e211cdc14087,
  abstract     = {{<p>BACKGROUND: Umbilical cord blood gases are routinely used by midwives and obstetricians for quality assurance of birth management and in clinical research. They can form the basis for solving medicolegal issues in the identification of severe intrapartum hypoxia at birth. However, the scientific value of veno-arterial differences in cord blood pH, also known as ΔpH, is largely unknown. By tradition, the Apgar score is frequently used to predict perinatal morbidity and mortality, however significant inter-observer and regional variations decrease its reliability and there is a need to identify more accurate markers of perinatal asphyxia. The aim of our study was to investigate the association of small and large veno-arterial differences in umbilical cord pH, ΔpH, with adverse neonatal outcome.</p><p>METHODS: This retrospective, population-based study collected obstetric and neonatal data from women giving birth in nine maternity units from Southern Sweden from 1995 to 2015. Data was extracted from the Perinatal South Revision Register, a quality regional health database. Newborns at ≥37 gestational weeks with a complete and validated set of umbilical cord blood samples from both cord artery and vein were included. Outcome measures included: ΔpH percentiles, 'Small ΔpH' (10th percentile), 'Large ΔpH' (90th percentile), Apgar score (0-6), need for continuous positive airway pressure (CPAP) and admission to neonatal intensive care unit (NICU). Relative risks (RR) were calculated with modified Poisson regression model.</p><p>RESULTS: The study population comprised of 108,629 newborns with complete and validated data. Mean and median ΔpH was 0.08 ± 0.05. Analyses of RR showed that 'Large ΔpH' was associated with a decreased RR of adverse perinatal outcome with increasing UApH (at UApH ≥7.20: RR for low Apgar 0.29, P = 0.01; CPAP 0.55, P = 0.02; NICU admission 0.81, P = 0.01). 'Small ΔpH' was associated with an increased RR for low Apgar score and NICU admission only at higher UApH values (at UApH 7.15-7.199: RR for low Apgar 1.96, P = 0.01; at UApH ≥7.20: RR for low Apgar 1.65, P = 0.00, RR for NICU admission 1.13, P = 0.01).</p><p>CONCLUSION: Large differences between cord venous and arterial pH (ΔpH) at birth were associated with a lower risk for perinatal morbidity including low 5-minute Apgar Score, the need for continuous positive airway pressure and NICU admission when UApH was above 7.15. Clinically, ΔpH may be a useful tool in the assessment of the newborn's metabolic condition at birth. Our findings may stem from the ability of the placenta to adequately replenish acid-base balance in fetal blood. 'Large ΔpH' may therefore be a marker of effective gas exchange in the placenta during birth.</p>}},
  author       = {{Sundberg, Tiia-Marie and Wiberg, Nana and Källén, Karin and Zaigham, Mehreen}},
  issn         = {{1471-2393}},
  keywords     = {{Pregnancy; Humans; Infant, Newborn; Female; Fetal Blood; Retrospective Studies; Proton-Motive Force; Reproducibility of Results; Arteries; Infant, Newborn, Diseases; Hydrogen-Ion Concentration; Apgar Score}},
  language     = {{eng}},
  month        = {{03}},
  pages        = {{1--9}},
  publisher    = {{BioMed Central (BMC)}},
  series       = {{BMC Pregnancy and Childbirth}},
  title        = {{Adverse neonatal outcome and veno-arterial differences in umbilical cord blood pH (ΔpH) at birth : a population-based study of 108,629 newborns}},
  url          = {{http://dx.doi.org/10.1186/s12884-023-05487-8}},
  doi          = {{10.1186/s12884-023-05487-8}},
  volume       = {{23}},
  year         = {{2023}},
}