Choroid Plexus Cyst
Chukwuma I. Onyeije, MD
Atlanta Perinatal Associates
What Is a Choroid Plexus Cyst?
A choroid plexus cyst (CPC) is a small, fluid-filled space within the choroid plexus — the part of the fetal brain that produces cerebrospinal fluid. It is not a brain defect.
Location
Found inside the lateral ventricles of the developing brain
Nature
A small pocket of fluid — not a structural brain abnormality
The Fetal Brain at Mid-Pregnancy
BPD Level Structures — the choroid plexus is visible within the posterior lateral ventricles
How Common Are Choroid Plexus Cysts?
The vast majority of CPCs resolve on their own before the third trimester and have no lasting consequences for your baby.
The Connection to Chromosomes
A CPC is a soft marker — a minor ultrasound finding that, in rare cases, may be associated with Trisomy 18 (Edwards syndrome).
Most of the time
An isolated CPC is a normal variation with no chromosome concern
Key distinction
CPCs do not increase risk for Trisomy 21 (Down syndrome)
A Detailed Ultrasound Examination
The first step is a comprehensive anatomy survey to confirm the CPC is an isolated finding — meaning no other structural differences are present.
- ✓ Careful review of all fetal organ systems
- ✓ Assessment for any additional soft markers
- ✓ Review of your prenatal screening results
Our Decision-Making Framework
When Screening Is Low-Risk
If your aneuploidy screen (NIPT or serum screen) is low-risk for Trisomy 18 and the CPC is isolated, no further genetic evaluation is recommended.
An isolated CPC with a negative screen is a normal variant of no clinical importance — no follow-up ultrasound or postnatal evaluation is required.
We Are Here for You
We are committed to providing you with clear information, compassionate care, and a trusted partnership throughout your pregnancy.
- ✓ Ask us any questions — no question is too small
- ✓ We will guide you through every step of the evaluation
- ✓ Our goal is your confidence and your baby’s wellbeing
Atlanta Perinatal Associates • Chukwuma I. Onyeije, MD