Introduction #
CT Pelvimetry is a special type of CT scan used to measure the size and shape of a woman’s bony pelvis. It is most commonly performed in pregnancy when doctors want to know if a baby can safely pass through the birth canal or if a Caesarean section (C-section) may be necessary.
This test provides accurate measurements that help guide obstetricians in making safe delivery plans for both mother and baby.
Common Indications for CT Pelvimetry #
Your doctor may recommend a CT Pelvimetry if:
• There are concerns about cephalopelvic disproportion (CPD) – the baby’s head may be too large to pass through the pelvis
• There is a history of previous difficult labor
• Your baby is in a breech or other abnormal position and vaginal delivery is being considered
• You had a previous C-section and a trial of vaginal delivery is planned
• There is a need to measure pelvic dimensions accurately after pelvic fractures or deformities
What does a CT Pelvimetry scanner looks like? #
The CT scanner is shaped like a wide, circular ring. You lie on a narrow table that gently moves through the center while images of your pelvis are captured.
What happens during a CT Pelvimetry procedure? #
• You will lie on your back with legs straight.
• The Radiographer may position you carefully to capture all necessary measurements.
• A quick series of images of your pelvis is taken, it usually lasts less than a minute.
• Specialized software is used to calculate key pelvic dimensions (inlet, outlet, diagonal conjugate, interspinous distance, etc.).
Do I need to prepare for CT Pelvimetry? #
No special preparation is usually required.
• You can eat and drink normally before the scan.
• Wear comfortable clothing but you may be asked to change into a hospital gown.
• Remove metallic objects around the pelvic area, such as belts, jewelry, or clothing with zippers or snaps.
Will contrast dye be used? #
No, CT Pelvimetry is performed without contrast dye because only the bones of the pelvis are being measured.
How long does CT Pelvimetry take? #
The scan itself is very quick, typically less than 5 minutes. Including preparation, you should expect to spend about 10–15 minutes in the CT department.
Is CT Pelvimetry safe during pregnancy? #
Yes, CT Pelvimetry uses a very low dose of radiation, and the scan is limited to the pelvic area to minimize fetal exposure.
Your doctor will only request it if the benefit outweighs the small radiation risk.
Does the scan hurt? #
No, CT Pelvimetry is painless. You only need to lie still for a short time.
What information does CT Pelvimetry provide? #
It provides:
• Accurate measurement of the size and shape of the pelvic bones
• An estimate of the space available for childbirth
• Helps guide decisions on whether vaginal delivery is likely to be safe or whether a C-section is recommended.
Conclusion #
CT Pelvimetry is a fast, safe, and reliable way to measure the pelvis and plan for a safe delivery. It is performed with very low radiation dose and gives doctors the critical measurements they need to guide delivery decisions.