title: Intrapartum monitoring with cardiotocography and ST-waveform analysis in breech presentation: an observational study.
abstract: OBJECTIVE
  To determine the electrocardiographic performance and neonatal outcome of pregnancies with breech presentation and planned vaginal delivery monitored with ST-waveform analysis (STAN).
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  University hospital, Norway; 2004-2008.
  
  
  METHODS
  Singleton pregnancies with a gestational age above 35 + 6 weeks, breech presentation, selected for vaginal delivery and monitored with STAN.
  
  
  METHODS
  Common clinical guidelines for STAN monitoring were used. An experienced neonatologist graded the symptoms of neonatal encephalopathy. The outcome was compared with STAN-monitored high-risk deliveries in a vertex presentation (n = 5569) using logistic regression analysis.
  
  
  METHODS
  Frequency of ST events, indications of intervention for fetal distress, and neonatal morbidity and mortality.
  
  
  RESULTS
  Breech presentation occurred in 750 of 23,219 (3.2%) deliveries, 625 (83%) of which were selected for vaginal delivery. Intrapartum monitoring by STAN was performed in 433 (69%). Compared with vertex presentations, fetuses in breech presentation had a lower risk of baseline T/QRS rise during labour [odds ratio (OR) = 0.7, 95% confidence interval (95% CI) = 0.7-0.9, P = 0.003] and a higher risk for intervention as a result of preterminal cardiotocogram (OR = 2.9, 95% CI = 1.6-5.9, P = 0.001). The risks of perinatal mortality (OR = 1.8, 95% CI = 0.2-15, P = 0.6), cord metabolic acidosis (OR = 0.8, 95% CI = 0.2-3.2, P = 0.7) and moderate or severe neonatal encephalopathy (OR = 1.8, 95% CI = 0.5-6.2, P = 0.3) did not differ significantly between breech and vertex deliveries.
  
  
  CONCLUSIONS
  STAN can be used for the surveillance of breech presentations selected for vaginal delivery with an acceptable neonatal outcome. The electrocardiogram (ECG) pattern during labour varies with the fetal presentation.
authors.affiliation: Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, Research Group for Pregnancy, Fetal Development and Birth, University of Bergen, Bergen, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Kessler
authors.forename: D
authors.initials: D
authors.lastname: Moster
authors.forename: S
authors.initials: S
authors.lastname: Albrechtsen
mesh_terms: D000138:Acidosis / Q000097:blood; D000328:Adult; D001034:Apgar Score; D001946:Breech Presentation / Q000175:diagnosis* / Q000503:physiopathology; D015148:Cardiotocography; D036861:Delivery, Obstetric; D004562:Electrocardiography; D005260:Female; D005316:Fetal Distress / Q000175:diagnosis*; D005311:Fetal Hypoxia / Q000175:diagnosis*; D005323:Fetal Monitoring / Q000379:methods; D005865:Gestational Age; D006340:Heart Rate, Fetal; D006801:Humans; D007231:Infant, Newborn; D009664:Norway / Q000453:epidemiology; D017410:Practice Guidelines as Topic; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D015995:Prevalence; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors
keywords: Breech presentation; ST-waveform analysis; fetal electrocardiogram (ECG); intrapartum monitoring; neonatal outcome