Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2010 May 13:340:c1471.
doi: 10.1136/bmj.c1471.

Strength of association between umbilical cord pH and perinatal and long term outcomes: systematic review and meta-analysis

Gemma L Malin  1 , Rachel K Morris, Khalid S Khan
Affiliations
Meta-Analysis

Strength of association between umbilical cord pH and perinatal and long term outcomes: systematic review and meta-analysis

Gemma L Malin et al. BMJ. .

Abstract

Objective: To evaluate the association between umbilical cord pH at birth and long term outcomes.

Design: Systematic review and meta-analysis.

Data sources: Medline (1966-August 2008), Embase (1980-August 2008), the Cochrane Library (2008 issue 8), and Medion, without language restrictions; reference lists of selected articles; and contact with authors.

Study selection: Studies in which cord pH at birth was compared with any neonatal or long term outcome. Cohort and case-control designs were included.

Results: 51 articles totalling 481 753 infants met the selection criteria. Studies varied in design, quality, outcome definition, and results. Meta-analysis carried out within predefined groups showed that low arterial cord pH was significantly associated with neonatal mortality (odds ratio 16.9, 95% confidence interval 9.7 to 29.5, I(2)=0%), hypoxic ischaemic encephalopathy (13.8, 6.6 to 28.9, I(2)=0%), intraventricular haemorrhage or periventricular leucomalacia (2.9, 2.1 to 4.1, I(2)=0%), and cerebral palsy (2.3, 1.3 to 4.2, I(2)=0%).

Conclusions: Low arterial cord pH showed strong, consistent, and temporal associations with clinically important neonatal outcomes that are biologically plausible. These data can be used to inform clinical management and justify the use of arterial cord pH as an important outcome measure alongside neonatal morbidity and mortality in obstetric trials.

PubMed Disclaimer

Conflict of interest statement

Competing interests: All authors have completed the unified competing interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare (1) no financial support for the submitted work from anyone other than their employer; (2) no financial relationships with commercial entities that might have an interest in the submitted work; (3) no spouses, partners, or children with relationships with commercial entities that might have an interest in the submitted work; and (4) no non-financial interests that may be relevant to the submitted work.

Figures

None
Fig 1 Study selection process
None
Fig 2 Association of low arterial cord pH with neonatal mortality. EPI=estimated predictive interval
None
Fig 3 Association of low arterial cord pH with neonatal morbidity. HIE=hypoxic ischaemic encephalopathy; IVH=intraventricular haemorrhage; PVL=periventricular leucomalacia; NS=not stated; WM=cerebral white matter; EPI=estimated predictive interval
None
Fig 4 Association of low arterial cord pH with cerebral palsy. NS=not stated; EPI=estimated predictive interval
See this image and copyright information in PMC

Comment in

References

    1. Heller G, Schnell RR, Misselwitz B, Schmidt S. Umbilical blood pH, Apgar scores, and early neonatal mortality. Z Geburtshilfe Neonatol 2003;207:84-9. - PubMed
    1. Goodwin TM, Belai I, Hernandez P, Durand M, Paul RH. Asphyxial complications in the term newborn with severe umbilical acidemia. Am J Obstet Gynecol 1992;167:1506-12. - PubMed
    1. Williams KP, Singh A. The correlation of seizures in newborn infants with significant acidosis at birth with umbilical artery cord gas values. Obstet Gynecol 2002;100:557-60. - PubMed
    1. Beeby PJ, Elliott EJ, Henderson-Smart DJ, Rieger ID. Predictive value of umbilical artery pH in preterm infants. Arch Dis Child 1994;71:F93-6. - PMC - PubMed
    1. Kato EH, Yamada H, Matsumoto Y, Hattori S, Makinoda S, Fujimoto S. Relation between perinatal factors and outcome of very low birth weight infants. J Perinat Med 1996;24:677-86. - PubMed

Publication types