This site is intended for healthcare professionals

Sign in
Go to /sign-in page

You can view 5 more pages before signing in

Chorionicity ultrasound

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

A chorionicity ultrasound is used to distinguish between twins that share a placenta and those who have separate ones, so that twins at higher risk of complications can be monitored more closely.

  • determine chorionicity and amnionicity at the time of detecting a twin or triplet pregnancy by ultrasound using:
    • the number of placental masses
    • the presence of amniotic membrane(s) and membrane thickness
    • the lambda or T-sign
  • if a woman with a twin or triplet pregnancy presents after 14+0 weeks, determine chorionicity and amnionicity at the earliest opportunity by ultrasound using all of the following:
    • the number of placental masses
    • the presence of amniotic membrane(s) and membrane thickness
    • the lambda or T-sign
    • discordant fetal sex

Chorionicity:

  • number of chorionic (outer) membranes that surround babies in a multiple pregnancy
    • If there is only 1 membrane, the pregnancy is described as monochorionic;
    • if there are 2, the pregnancy is dichorionic; and
    • if there are 3, the pregnancy is trichorionic
  • monochorionic twin pregnancies and monochorionic or dichorionic triplet pregnancies carry higher risks because babies share a placenta

Reference:

Related pages

Create an account to add page annotations

Create a free account

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.