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Gestational age-dependent reference values for pH in umbilical cord arterial blood at term

Kitlinski, Margareta LU ; Källén, Karin LU ; Marsal, Karel LU and Olofsson, Per LU (2003) In Obstetrics and Gynecology 102(2). p.338-345
Abstract
OBJECTIVE: Despite a change of fetal physiologic and biochemical functions with gestational age, stationary umbilical cord acid-base reference values are used as measures of obstetric care quality. The aim of this study was to assess the risk of low Apgar score relative to low pH when using stationary versus gestational age-adjusted reference values. METHODS: Umbilical artery pH was determined in 24,390 term singleton vaginal deliveries with a 5-minute Apgar score of 9 or greater. Low pH was defined as less than 7.10 as a stationary cutoff value, whereas pH less than (mean 2 standard deviations [SDs)) was used when gestational age was considered. The 5-minute Apgar score less than 7 at low pH was studied in 44,978 term deliveries. RESULTS:... (More)
OBJECTIVE: Despite a change of fetal physiologic and biochemical functions with gestational age, stationary umbilical cord acid-base reference values are used as measures of obstetric care quality. The aim of this study was to assess the risk of low Apgar score relative to low pH when using stationary versus gestational age-adjusted reference values. METHODS: Umbilical artery pH was determined in 24,390 term singleton vaginal deliveries with a 5-minute Apgar score of 9 or greater. Low pH was defined as less than 7.10 as a stationary cutoff value, whereas pH less than (mean 2 standard deviations [SDs)) was used when gestational age was considered. The 5-minute Apgar score less than 7 at low pH was studied in 44,978 term deliveries. RESULTS: A significant negative correlation was found between gestational age and umbilical artery pH. ne odds ratio (OR) for pH less than 7.10 was continuously increasing, from 0.6 at 37 weeks to 1.5 at 42 weeks. In contrast, the OR for pH less than (mean - 2 SDs) was steady until 42 weeks, whereafter it increased (OR 1.24; 95% confidence interval 1.05, 1.47). A linear decrease of the association between Agar score less than 7 and pH less than 7.10 with increasing pregnancy duration was found (P =.097), but for pH less than (mean - 2 SDs) there was no such association. CONCLUSION: We found a physiologic linear decline of umbilical artery pH with gestational age at term. Gestational age-adjusted umbilical cord artery pH reference values result in fewer diagnoses of cord acidemia than a stationary cutoff of pH less than 7.10. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Obstetrics and Gynecology
volume
102
issue
2
pages
338 - 345
publisher
Lippincott Williams & Wilkins
external identifiers
  • wos:000184450800022
  • pmid:12907110
  • scopus:0042697686
ISSN
1873-233X
DOI
10.1016/S0029-7844(03)00512-X
language
English
LU publication?
yes
id
ef26504b-6be3-42db-82e4-7ddf8ac75d5e (old id 304922)
alternative location
http://www.greenjournal.org/cgi/content/abstract/102/2/338
date added to LUP
2007-09-16 07:52:00
date last changed
2018-01-07 08:47:19
@article{ef26504b-6be3-42db-82e4-7ddf8ac75d5e,
  abstract     = {OBJECTIVE: Despite a change of fetal physiologic and biochemical functions with gestational age, stationary umbilical cord acid-base reference values are used as measures of obstetric care quality. The aim of this study was to assess the risk of low Apgar score relative to low pH when using stationary versus gestational age-adjusted reference values. METHODS: Umbilical artery pH was determined in 24,390 term singleton vaginal deliveries with a 5-minute Apgar score of 9 or greater. Low pH was defined as less than 7.10 as a stationary cutoff value, whereas pH less than (mean 2 standard deviations [SDs)) was used when gestational age was considered. The 5-minute Apgar score less than 7 at low pH was studied in 44,978 term deliveries. RESULTS: A significant negative correlation was found between gestational age and umbilical artery pH. ne odds ratio (OR) for pH less than 7.10 was continuously increasing, from 0.6 at 37 weeks to 1.5 at 42 weeks. In contrast, the OR for pH less than (mean - 2 SDs) was steady until 42 weeks, whereafter it increased (OR 1.24; 95% confidence interval 1.05, 1.47). A linear decrease of the association between Agar score less than 7 and pH less than 7.10 with increasing pregnancy duration was found (P =.097), but for pH less than (mean - 2 SDs) there was no such association. CONCLUSION: We found a physiologic linear decline of umbilical artery pH with gestational age at term. Gestational age-adjusted umbilical cord artery pH reference values result in fewer diagnoses of cord acidemia than a stationary cutoff of pH less than 7.10.},
  author       = {Kitlinski, Margareta and Källén, Karin and Marsal, Karel and Olofsson, Per},
  issn         = {1873-233X},
  language     = {eng},
  number       = {2},
  pages        = {338--345},
  publisher    = {Lippincott Williams & Wilkins},
  series       = {Obstetrics and Gynecology},
  title        = {Gestational age-dependent reference values for pH in umbilical cord arterial blood at term},
  url          = {http://dx.doi.org/10.1016/S0029-7844(03)00512-X},
  volume       = {102},
  year         = {2003},
}