1. Assess differences in flow patterns in the fetal cerebral blood vessels within 24 hours before delivery between fetuses with a normal vs. adverse perinatal outcome.
2. Explore maternal and/or fetal characteristics that might influence technical feasibility of doppler sonography of the fetal cerebral blood vessels in early labor at term.
3. Assess reliability of the technique by measuring intra- and inter-observer variation in a subset of participants.

Inclusion Criteria:

• Singleton pregnancy.
• Term gestation (37-42 weeks).
• Fetus in cephalic presentation.
• No known fetal chromosomal or (severe) congenital anomaly.
• Normally grown fetus (ultrasound scan demonstrating normal fetal growth between 30-37 weeks of gestation, defined as an estimated fetal weight/abdominal circumference > 10th centile or crossing <2 quartiles compared to earlier growth ultrasound).
• Absence of pre-existing doppler or amniotic fluid abnormalities.
• Normal fetal heart rate tracing / CTG (excluding pre-existing hypoxia).
• Admission in early spontaneous labor or induction of labor with expected delivery < 24 hours.
• Maternal age >= 18 years
• Willing to give written informed consent.

Exclusion Criteria:

• Advanced labor (> 4cm of cervical dilatation) at the time of admission on the labor ward.
• Severe pre-existing chronic maternal medical condition or poor obstetric history/antenatal complications associated with increased risk of adverse perinatal outcome (non-exhaustive e.g.: uncontrolled chronic hypertension, severe pre-eclampsia, uncontrolled (gestational) diabetes, maternal sepsis, major antepartum haemorrhage, intra-uterine infection, prolonged rupture of membranes > 18 hours, etc.).
• Intra-uterine fetal demise / death.
• Prelabour rupture of membranes with meconium-stained amniotic fluid.
• Patients not fulfilling all the inclusion criteria or refusing to give written informed consent.

Pregnant women

"Low-risk" pregnant women