Related Experiment Video
Updated: Jul 9, 2026
A Modified Sonographic Algorithm for Image Acquisition in Life-Threatening Emergencies in the Critically Ill Newborn
Published on: April 7, 2023
The relationship between umbilical arterial pH, newborn heart rate and ventilation at birth - a prospective
Siren Rettedal1, Frederikke Buskov1, Amalie Kibsgaard2
1Department of Simulation-based Learning, Stavanger University Hospital, 4021 Stavanger, Norway; Faculty of Health Sciences, University of Stavanger 4021 Stavanger, Norway.
Objective:
To investigate the relationship between umbilical arterial pH (UA-pH), heart rate (HR) and positive pressure ventilation (PPV) at birth.
Methods:
A prospective cohort study conducted at Stavanger University Hospital, Norway, June 2019-November 2021. Newborns of gestational age ≥28 weeks were eligible for inclusion. UA-pH was routinely obtained at birth and newborn HR captured using dry-electrode ECG. Relationships were evaluated using linear correlation and logistic regression. UA-pH was categorised as <7.00, 7.00-7.09, 7.10-7.19, with reference group 7.20-7.50. Outcome measures were newborn HR and PPV.
Results:
Among 3662 newborns the median (quartiles) UA-pH was 7.24 (7.19, 7.29). UA-pH <7.00 was identified in 20 (0.5%), 7.00-7.09 in 140 (3.8%), 7.10-7.19 in 833 (23%), and 7.20-7.50 in 2669 (73%) newborns. There was a weak and clinically insignificant linear correlation between UA-pH and first measured HR at 16 (11, 30) s (r = 0.07, p < 0.001), and no linear correlation with HR at one minute (r = -0.03, p = 0.07). Even among newborns with UA-pH <7.00, only 50% were bradycardic with HR values <100 bpm in the first minute (OR 5.0 (1.9, 12.9), p < 0.001). PPV was provided to 117/3662 (3.2%) of newborns. One-third with UA-pH <7.00 received PPV at birth (OR 21.9 (8.0, 55.4), p < 0.001). Apgar scores were strongly associated with UA-pH.
Conclusion:
There was no linear correlation between UA-pH and HR at one minute. Although HR alone was not a good indicator of acidaemia, low UA-pH is associated with bradycardia and PPV. Apgar scores reflected the degree of birth asphyxia very well.
Clinical Trial Registration:
NCT03849781.
Related Concept Videos
01:20Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
01:14Fetal Circulation
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
01:19Special considerations while measuring oxygen saturation
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is important.
01:29Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement: