Caesarean section

Primigravida in the third trimester attends the obstetrician. The obstetrician performs an ultrasound to check the foetal position, size and movement, amount of the amniotic fluid and measures the patient’s blood pressure. The findings show cephalopelvic disproportion. What does it mean?
woman
RR
16 /min
BP
110/70 (83) mmHg