The Oslo Stan vs Lactate Observational Study

The Oslo Stan vs Lactate Observational Study, an Observational Study Were we Compare the Clinical Performance of Two Adjunctive Methods to CTG in Intrapartum Fetal Monitoring

The main aim of the study is to compare the clinical performance of two adjunctive methods to CTG in intrapartum fetal monitoring: FBS with measurement of scalp lactate and ST analysis of the fetal ECG.

We use Lactate as a standard adjunctive method in our hospital but we have STAN software available ( is demasked) in our CTG monitors. We will include all women in labour with an intern scalp monitoring and analyse the CTG, the lactate samples and the STAN signals in the same patient and

• Study the relationship between the decision-to-delivery interval and neonatal morbidity in deliveries monitored by scalp lactate measurement
• Compare the diagnostic capability of both methods to identify fetuses at risk of hypoxia
• Compare the false negative alerts from both methods
• Explore the temporal and quantitative relation between fetal lactate metabolism and ST interval changes of the fetal ECG
• Investigate the occurrence of fetal extrasystoles during labor and to assess their association with short-term neonatal outcomes

Inclusion Criteria:

• Singleton pregnancy
• Cephalic presentation
• Gestational age ≥36+0 weeks at delivery
• Presence of antpartum or intrapartum risk factors for fetal hypoxia according to Norwegian guidelines and therefore indication for electronic fetal monitoring with scalp electrode .

Exclusion Criteria:

• Multiple pregnancies
• Breech presentation
• Gestational age < 36+0 weeks
• Contraindications for placement of a scalp electrode (HIV or HBV or HCV pos)