Understanding intraabdominal cysts
What is an intraabdominal cyst?
An intra-abdominal cyst is a fluid-filled structure, much like a little ballon, identified in the baby’s abdomen on prenatal ultrasound. These cysts are relatively uncommon and most are benign. The outcome depends on the cyst’s size, location, appearance, and behavior over time.
Where can a cyst occur?
A cyst can originate in any organ within the abdomen. The most commonly seen cysts include:
- Ovary (in a female fetus)
- Bowel (also called a duplication cyst)
- Mesenteric (often within the fat surrounding intestine)
- Choledochal (found in the bile drainage system)
Others places that a cyst can be found also include:
- Adrenal gland (also referred to as suprarenal gland)
- Pancreas
- Liver
- Kidney
- Lymphatic system
Fetal Center: the first step in care
Multidisciplinary Evaluation: meet with MFM specialist, pediatric surgeon, neonatologist, and other experts who may care for your baby
Comprehensive Imaging: detailed ultrasounds and other tests when indicated to assess your baby's condition and help plan treatment
Coordinated Delivery Planning: our team works to ensure your baby receives immediate specialized care at birth if needed
How is an intraabdominal cyst evaluated?
- Regular monitoring with a detailed ultrasound throughout pregnancy is recommended to assess:
- Size and growth over time
- Location (e.g., ovarian, gastrointestinal, urinary, hepatic)
- Internal features (simple vs complex, septations, debris)
- Effects on nearby organs (bowel obstruction, urinary tract dilation, hydrops)
- A fetal MRI in not obtained routinely, but sometimes when indicated to further evaluate other structures as indicated
- Genetic testing is not typically recommended as it is usually isolated without chromosomal abnormalities
(Pic: fetal ultrasound with arrow demonstrating intraabdominal cyst)
Where should the baby deliver?
Based on our evaluation, we can help determine where the baby can safely be delivered. In most cases, the timing and mode of delivery are usually unchanged and vaginal delivery is usually appropriate.
For larger, fast growing or uncertain cysts, delivery at a center with neonatal imaging and pediatric surgical expertise is preferred
What is the initial treatment?
The first step in management is newborn resuscitation and stabilization, making sure the baby is able to breathe appropriately and the heart is functioning properly just like for any newborn. Most will then go home once they have meet the appropriate discharge criteria for their pediatrician.
The child will then follow-up over the course of the next several months with a pediatric surgeon for reevaluation. with the following plan:
Observation
This is typically done with frequent clinic evaluation and abdominal ultrasound every 3 - 6 months.
- Many cysts regress or resolve spontaneously.
- Appropriate for:
- Small, simple, asymptomatic cysts
- Stable or decreasing size
Surgical intervention is indicated if:
- The cyst is large, growing, or complex
- There are symptoms (vomiting, feeding intolerance, abdominal distention)
- There is concern for complications (torsion, obstruction, infection, rupture)
- Timing is usually elective unless urgent symptoms arise, around 6 - 12 months
Outcomes and Long-term outlook
The overall prognosis is excellent and most infants do well with either observation or surgery, with normal long-term outcomes
