What Causes Cephalopelvic Disproportion?


What is Cephalopelvic Disproportion (CPD)?

During labor and delivery, a baby has to pass through the narrow opening in the mother’s pelvis. Cephalopelvic Disproportion (CPD) is a condition where the baby has trouble getting through the birth canal because of the size of the baby’s head, the baby’s position, or the size or shape of the mother’s pelvis. The baby’s head might be too large, or the mother’s pelvis might be too small, or both. If not treated correctly, obstructed labor caused by CPD can be dangerous to both the mother and baby.

Sometimes people make a distinction between “true” CPD and other causes of obstructed labor, with true CPD referring only to the situation where the baby’s head is too large for the mother’s pelvis. However, many doctors use the term CPD to refer to all situations where labor is obstructed and fails to progress.

Causes of Cephalopelvic Disproportion

1. The baby is very large.

Fetal macrosomia is the medical term for the condition where a baby is unusually large. The risk of problems during delivery is elevated when a baby weighs more than 8 pounds, 13 ounces. The risk is even higher for babies weighing more than 9 pounds, 15 ounces.

There are several risk factors for large babies. These include:


  • The mother has diabetes.
  • The mother is obese or gained a great deal of weight during pregnancy.
  • The mother previously had a large baby or was herself a large baby.
  • The pregnancy lasts past term.
  • The baby has a condition, such as hydrocephalus, that makes their head larger.
  • The baby is a boy (because boys tend to be larger).


2. The baby’s position is problematic.

Babies will have the best chance of passing through the mother’s pelvis if they are in the occiput anterior position, which is head down and facing the mother’s back.

If a baby has rotated, is in a breech potion, is lying sideways, or is leading with their forehead or face, he or she will have a harder time fitting through the opening in the mother’s pelvic bones.


3. The mother’s pelvis is too small or has an abnormal shape.

A pelvis that is small enough or abnormally shaped enough to cause problems during labor is called a contracted pelvis. This condition can be hereditary, congenital, or caused by injury or illness.

Diseases and conditions that can affect the size or shape of the pelvis include:


    • Rickets
    • Bony growths
    • Spinal bones slipping out of position
    • Bone tumors

How is CPD Diagnosed?

Cephalopelvic disproportion is usually not diagnosed in advance. It’s generally diagnosed during labor if the baby’s progress through the birth canal is taking longer than expected. Doctors should be closely monitoring the baby’s progress and heart rate, the dilation of the mother’s cervix, and the strength of her uterine contractions. It may be necessary to confirm the baby’s position with a vaginal exam, x-rays, ultrasound, or MRI.

How is CPD Diagnosed?

How is CPD Treated?

When a baby is having trouble getting through the birth canal, a vaginal delivery poses a danger to both the baby and the mother. Doctors may recommend moving on to a cesarean section right away, or they may try letting labor go on a while longer. The mother may try moving into different positions, such as squatting or kneeling on hands and knees, which might facilitate the baby’s passage. However, if the labor is still abnormally delayed, a C-section will be necessary to avoid dangerous complications.

Possible Complications of Cephalopelvic Disproportion

If CPD is not properly treated:


  • Medical Negligence and Cephalopelvic Disproportion

    Medical personnel must carefully monitor the mother and baby during delivery. If the baby’s progress is delayed, doctors must take appropriate action. If they fail to act skillfully, as quickly as necessary, and according to the applicable medical standards, they are negligent. If harm to the baby or mother results from their negligence, then they have committed medical malpractice.

    Legal Help If Your Baby Suffered a Birth Injury Because of CPD

    If your baby was diagnosed with cephalopelvic disproportion, and your baby suffered a birth injury or other harm, you may be entitled to seek compensation for your baby’s injuries if medical professionals commited malpractice. We invite you to consult the birth injury lawyers at the Raynes & Lawn law firm. Proving medical malpractice is a complex undertaking that requires highly experienced lawyers. We are trial attorneys who have been dedicated to achieving justice for our clients for half a century and have been recognized nationally and locally for the excellence of our legal work. Contact us at 1-800-535-1797 for a free consultation.

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