Low-Lying Placenta (Not Previa)
The short answer
A low-lying placenta found on the 18-22 week anatomy scan is very common and usually not a cause for concern. As the uterus grows, the placenta appears to "migrate" upward in over 90% of cases, resolving by the third trimester. Your provider will recheck the placenta position later in pregnancy.
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By Age
What to expect by age
At the anatomy scan, if the placenta is noted to be low-lying (within 2 cm of the cervix) or covering the cervix, a follow-up ultrasound will be scheduled around 32-36 weeks. In the vast majority of cases, the placenta moves away from the cervix as the lower uterine segment stretches and grows. Activity restrictions are usually not needed at this stage unless you are having bleeding.
A repeat ultrasound will confirm whether the placenta has moved. If the placenta remains low-lying or is covering the cervix (placenta previa) at 32-36 weeks, your provider will discuss delivery planning. A cesarean delivery is needed if the placenta covers the cervix at the time of delivery. Avoid intercourse if advised and report any bleeding immediately.
What Should You Do?
When to take action
- Low-lying placenta identified at the 20-week scan - this is very common
- No bleeding or symptoms
- Follow-up scan shows the placenta has moved away from the cervix
- You want to understand what a low-lying placenta means for your pregnancy
- You are experiencing any spotting or light bleeding
- You want to know about any activity restrictions
- Any vaginal bleeding, especially painless bright red bleeding in the second or third trimester
- Heavy bleeding with or without pain
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
Placenta Previa
Placenta previa means the placenta partially or completely covers the cervix. It is found in about 1 in 200 pregnancies at delivery. Many cases of low-lying placenta detected on mid-pregnancy ultrasound resolve on their own as the uterus grows. When placenta previa persists, a planned cesarean delivery is necessary, and with proper monitoring most outcomes are excellent.
Placenta Position Concerns
The placenta can attach anywhere on the uterine wall - anterior (front), posterior (back), fundal (top), or lateral (sides). All positions are normal. An anterior placenta may cushion the baby's movements, making kicks feel less intense or take longer to notice. The only concern is when the placenta is low-lying or covering the cervix (placenta previa).
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.
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.
20-Week Anatomy Scan Unexpected Findings
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.