Placental thickness

Placental thickness tends to gradually increase with gestational age in a linear fashion. Sonographically, this can be seen to be approximately 1 mm per week and the thickness of the placenta can be used to approximate gestational age:

  • approximate gestational age (in weeks) = placental thickness +/- 10 mm

The maximum thickness of a normal placenta at any point during pregnancy is often taken considered to be 4 cm 3

An abnormally increased placental thickness falls under the spectrum of placentomegaly. This can happen with number of conditions and is associated with increased risk of placental insufficiency. Causes include:

An abnormally decreased placental thickness can be seen seen with:

Share article

Article Information

rID: 13571
Section: Approach
Tag: cases
Synonyms or Alternate Spellings:
  • Thickness of the placenta

Support Radiopaedia and see fewer ads

Updating… Please wait.

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.