Occurrence	Risk factors
Antenatal
Fetal	Abnormal umbilical artery Doppler velocimetry
	Breech presentation
	Intrauterine growth restriction
	Multiple pregnancies
	Oligohydramnios
	Rh isoimmunization
Maternal	Anemia
	Antepartum hemorrhage
	Cardiac disease
	Diabetes
	Hypertension (preeclampsia or eclampsia)
	Hyperthyroidism
	Maternal motor vehicle collision or trauma
	Morbid obesity
	Renal disease
	Vascular disease
Intrapartum
Fetal	Abnormal fetal heart rate on auscultation or admission
	tracing (20-minute strip)*
	Meconium-stained amniotic fluid
Maternal	Hypertonic uterus
	Induced or augmented labor
	Intrauterine infection or chorioamnionitis
	Post-term pregnancy (> 42 weeks' gestation)
	Preterm labor (< 32 weeks' gestation)
	Previous cesarean delivery
	Prolonged membrane rupture > 24 hours at term
	Regional analgesia, particularly after initial bolus and after top-ups (continuous electronic fetal monitoring is not required with mobile or continuous-infusion epidurals)
	Vaginal bleeding in labor