From the Guidelines
Assessing for cephalopelvic disproportion (CPD) should involve a thorough clinical evaluation, including maternal history, physical examination of the pelvis, and ultrasound assessment of fetal size, as well as monitoring labor progression and watching for warning signs of CPD, such as excessive molding of the fetal head or failure to progress despite adequate contractions, as recommended by recent studies 1. To assess for CPD, begin with a thorough clinical assessment including:
- Maternal history (previous difficult deliveries, maternal height under 5 feet, history of pelvic trauma or fractures)
- Physical examination of the pelvis (diagonal conjugate measurement via vaginal examination)
- Evaluation of fetal size through Leopold's maneuvers and fundal height measurement Ultrasound assessment is crucial for estimating fetal weight and head circumference, with special attention to biparietal diameter, as noted in recent studies 1. During labor, monitor labor progression using a partogram, as failure to progress despite adequate contractions may suggest CPD, and watch for warning signs such as:
- Excessive molding of the fetal head
- Caput succedaneum formation
- The "turtle sign" where the fetal head retracts after contractions Pelvimetry using X-ray, CT, or MRI may be used in select cases, though it's less common in modern practice, and advanced 3- or 4-dimensional sonography or other imaging techniques may be used to assess for possible CPD with greater sophistication, accuracy, and nuanced clinical interpretation, as suggested by recent studies 1. CPD assessment is important because unrecognized disproportion can lead to prolonged labor, maternal exhaustion, fetal distress, and potential birth trauma, while early recognition allows for timely intervention with cesarean delivery when necessary, as emphasized by recent studies 1.