Acidemia at birth, related to obstetric characteristics and to oxytocin use, during the last two hours of labor

• Objective. Evaluate obstetric characteristics during the last two hours of labor in neonates born with acidemia. Design. Case-control study. Setting. Delivery units at two university hospitals in Sweden. Study population. Out of 28,486 deliveries during 1994-2004, 305 neonates had an umbilical artery pH value <7.05 at birth. Methods. Cases: neonates with an umbilical artery pH < 7.05. Controls were neonates with pH ≥ 7.05 and an Apgar score ≥7 at 5 minutes. Obstetric characteristics, cardiotocographic patterns and oxytocin treatment during the last two hours of labor were recorded. Results. In the univariate analysis, ≥6 contractions/10 minutes (odds ratio (OR) 4.94, 95% confidence interval (CI) 3.25-7.49), oxytocin use (OR 2.20, 95% CI 1.66-2.92), bearing down ≥45 minutes (OR 1.77, 95% CI 1.31-2.38) and occipito-posterior position (OR 2.18, 95% CI 1.19-3.98) were associated with acidemia at birth. In the multivariate analysis, only ≥6 contractions/10 minutes (OR 5.36, 95% CI 3.32-8.65) and oxytocin use (OR 1.89, 95% CI 1.21-2.97) were associated with acidemia at birth. Among cases with ≥6 contractions/10 minutes, 75% had been treated with oxytocin. Pathological cardiotocographic patterns occurred in 68.8% of cases and in 26.1% of controls (p<0.001). Conclusion. A hyperactive uterine contraction pattern and oxytocin use are the most important risk factors for acidemia at birth. The increased uterine activity was related to overstimulation in the majority of cases. The duration of bearing down is less important when uterine contraction frequency has been considered.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Reproduktionsmedicin och gynekologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Obstetrics, Gynaecology and Reproductive Medicine (hsv//eng)

Nyckelord

Acidosis/*etiology

Adult

Cardiotocography

Case-Control Studies

Female

Humans

Hydrogen-Ion Concentration

Labor Stage; Second

Multivariate Analysis

Oxytocics/administration & dosage/*adverse effects

Oxytocin/administration & dosage/*adverse effects

Pregnancy

Risk Factors

Umbilical Arteries/chemistry

Umbilical Cord

Uterine Contraction

MEDICINE

MEDICIN

Obstetrics and women's diseases

Obstetrik och kvinnosjukdomar

Obstetrik och gynekologi

Obstetrics and Gynaecology

Publikations- och innehållstyp

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