20-Week Anatomy Scan Unexpected Findings
The short answer
The 20-week anatomy scan checks your baby's major organs, structures, and growth. Most scans are completely normal. When unexpected findings are identified, they range from minor variants that resolve on their own to conditions that need further evaluation. Many findings require nothing more than a follow-up ultrasound to confirm the baby is developing well.
This is one of the most common questions parents ask. Searching for answers means you care.
By Age
What to expect by age
The anatomy scan (18-22 weeks) examines the brain, heart, spine, kidneys, limbs, and other structures. If something unexpected is found, your provider may recommend a detailed follow-up ultrasound with a maternal-fetal medicine specialist, genetic counseling, or additional testing. Many findings (like a slightly dilated kidney or choroid plexus cyst) are common and resolve on their own.
Follow-up ultrasounds may be scheduled to recheck any findings. Many conditions that were uncertain at 20 weeks become clearer later in pregnancy. Your care team will guide you through any additional monitoring or planning needed based on confirmed findings.
What Should You Do?
When to take action
- All structures appearing normal on the anatomy scan
- Minor findings noted as "variants of normal" that require only follow-up
- Feeling anxious about the scan - this is completely understandable
- You want to better understand findings from your anatomy scan
- You would like a second opinion or detailed follow-up
- You are struggling emotionally with unexpected findings
- You are overwhelmed and need immediate emotional support after receiving unexpected news
- You want to discuss diagnostic testing options urgently
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
Worrying about your baby means you care. That is a good thing.
Related Maternal Concerns
Soft Markers on Ultrasound
Soft markers are minor ultrasound findings that are usually variants of normal but may slightly increase the statistical risk of chromosomal conditions. Common soft markers include echogenic intracardiac focus (bright spot on heart), choroid plexus cysts (small cysts in the brain), and mild pyelectasis (slightly dilated kidneys). An isolated soft marker (one finding with no other concerns) is usually not significant.
Dealing with Abnormal Prenatal Screening Results
An abnormal prenatal screening result can be terrifying, but it is important to understand that screening tests are designed to cast a wide net and have significant false-positive rates. Most people with abnormal screening results go on to have healthy babies after further testing confirms the baby is fine. An abnormal screening is a reason for more information, not a diagnosis.
Anxiety About Prenatal Tests
Anxiety about prenatal tests is extremely common. Many parents feel nervous about what tests might reveal. Remember that most screening tests have a high rate of reassuring results, and even abnormal screenings often turn out to be false positives. You have the right to choose which tests you want and to decline any test. Understanding what each test tells you can help reduce anxiety.
Pregnancy Over 35 (Advanced Maternal Age)
While pregnancy after 35 carries some increased risks (including chromosomal abnormalities, gestational diabetes, and hypertension), the vast majority of people over 35 have healthy pregnancies and healthy babies. The term "geriatric pregnancy" is outdated and does not reflect reality. With appropriate prenatal care and monitoring, outcomes are excellent.
Amniocentesis Questions and Fears
Amniocentesis is a diagnostic test performed between 15-20 weeks that analyzes amniotic fluid to detect chromosomal conditions and genetic disorders with over 99% accuracy. The risk of pregnancy loss from the procedure is approximately 1 in 500-1,000 when performed by an experienced provider. Understanding the actual risks can help you make an informed decision.
Less Movement with Anterior Placenta
An anterior placenta (attached to the front wall of the uterus) acts as a cushion between the baby and your belly wall, which can make movements feel muffled or less intense. You may feel movement later (22-24 weeks instead of 18-20) and primarily on the sides and lower belly. This is normal, but you should still feel regular movement once it is established.