How is cephalopelvic disproportion diagnosed (CPD)?
The diagnosis of cephalopelvic disproportion is often used when labor progress is not sufficient and medical therapy such as use of oxytocin is not successful or attempted. CPD can rarely be diagnosed before labor begins even if the baby is thought to be large or the mom’s pelvis is known to be small. During labor, the baby’s head molds and the pelvis joints spread, creating more room for the baby to pass through the pelvis. Ultrasounds are used to estimate fetal size, however they are not 100% accurate in determining fetal weight. A physical examination that measures pelvic size can often be the most accurate at determining a diagnosis of CPD. If a true diagnosis of CPD cannot be made, the use of oxytocin is often administered to see if this aides in labor progresssion or change in fetal postioning.
