At the 20-week scan, your sonographer looks at your baby’s tummy, including the stomach, bowel, kidneys and bladder. Sometimes part of the bowel looks brighter than usual on the scan, almost as bright as bone. This is called echogenic bowel, and it may also be described as hyperechogenic or bright bowel.
In most pregnancies, echogenic bowel is a normal finding that fades later in pregnancy, and the baby is healthy. However, it can occasionally be linked to other conditions, so a careful assessment and a few simple tests are usually recommended.
Key points
- Echogenic bowel means part of the baby’s bowel looks as bright as bone on the scan.
- In most pregnancies it is a normal finding that fades later in pregnancy, and the baby is healthy.
- It can be caused by the baby swallowing a small amount of blood, for example after bleeding in pregnancy, which is harmless.
- Less often, it is linked to a chromosomal condition, cystic fibrosis, an infection such as cytomegalovirus (CMV), a problem with the placenta or, rarely, a bowel blockage.
- Simple blood tests for you, and sometimes your partner, can check for infection and for cystic fibrosis.
- Follow-up scans check your baby’s growth and bowel later in pregnancy.
- A specialist fetal medicine review brings all the findings together to plan the right care.
What is echogenic bowel?
An ultrasound scan creates a picture from sound waves that bounce back, or reflect, from the baby’s tissues. This reflected sound is called an echo. Different tissues reflect sound differently depending on how dense they are, so some tissues generate more echoes than others. Bone reflects the most sound, so it looks the brightest, almost white. The bowel normally looks grey.
When an area of the bowel reflects as much sound as bone and looks as bright as the surrounding bone, it is described as echogenic, meaning echo-generating.
Echogenic bowel is seen in up to about 1 to 2 in 100 pregnancies at the 20-week scan, depending on how it is defined. It is not a disease in itself. It is a scan appearance that can have several different explanations.
How is it assessed?
The brightness of the picture can be controlled on the scan machine and depends partly on the machine settings. When the brightness of tissues is being assessed, the settings therefore need to be adjusted appropriately, and the bowel is compared directly with the baby’s nearby bones, such as the pelvis bones.
Echogenic bowel should only be diagnosed when the bowel is as bright as bone. Bowel that only appears bright because of the machine settings, or because of how the image has been assessed, is not echogenic bowel, and care is taken to avoid this overdiagnosis.
The scan also checks:
- whether the brightness is in one small area or in several areas
- whether any loops of bowel look widened
- the rest of your baby’s anatomy, including the heart, the liver and the brain
- your baby’s size and growth
- the placenta, its blood flow and the amount of fluid around the baby.
What can cause echogenic bowel?
There are several possible explanations. Often no cause is found and the baby is healthy.
1. Swallowed blood
If you have had some bleeding in pregnancy, or had an amniocentesis, your baby may have swallowed a little blood with the amniotic fluid. This can make the bowel look bright for a while. It is harmless and usually fades.
2. Chromosomal conditions
Echogenic bowel is one of the soft markers for Down’s syndrome and some other chromosomal conditions. This is discussed further below.
3. Cystic fibrosis
Cystic fibrosis is an inherited condition that affects the lungs and digestive system. It can make the bowel contents thick and sticky, which looks bright on the scan. In a large review, about 2 in 100 babies with isolated echogenic bowel had cystic fibrosis.
4. Infection
Some infections passed from the mother to the baby, most commonly cytomegalovirus (CMV), can cause echogenic bowel. CMV is a common virus that usually causes a mild cold-like illness, or no symptoms, in adults. About 2 in 100 babies with isolated echogenic bowel had a congenital infection.
5. Problems with the placenta or growth
Echogenic bowel can be an early sign that the placenta is not supplying the baby as well as it should. This is why your baby’s growth is checked later in pregnancy.
6. Bowel blockage
Rarely, echogenic bowel is an early sign of a narrowing or blockage of the bowel. This usually becomes clearer on later scans, when loops of bowel may look widened.
Is it linked to Down’s syndrome?
Echogenic bowel is more common in babies with Down’s syndrome than in other babies. As an isolated finding, it slightly increases the chance of Down’s syndrome, and how much this matters depends on your earlier screening result.
A holistic fetal medicine review is essential. This includes a detailed assessment of your baby’s anatomy, a careful check for any other associated markers, and a review of your first-trimester chance of Down’s syndrome from combined screening. If you have had NIPT, this result is also taken into account. Depending on these findings, we will discuss whether NIPT or a diagnostic test such as amniocentesis would be helpful.
For further information, read: Genetic Markers and Soft Markers at the 20-Week Scan
What tests may be offered?
The tests offered depend on the scan findings and your earlier results. They are designed to look for the less common causes, so that you can be reassured or appropriate care can be planned.
| Possible cause | How it is checked |
|---|---|
| Swallowed blood | Asking about any bleeding in pregnancy or a recent amniocentesis |
| Chromosomal conditions | Review of your earlier screening, a detailed scan, and discussion of NIPT or amniocentesis |
| Cystic fibrosis | A blood test for both parents to see whether you carry a cystic fibrosis gene change |
| Infection such as CMV | A blood test for you to look for recent infection |
| Placenta or growth problems | Growth and Doppler scans later in pregnancy |
| Bowel blockage | Follow-up scans to check the bowel and the fluid around your baby |
If both parents carry a cystic fibrosis gene change, or a recent infection is found, you will be offered a detailed discussion about further testing, which may include an amniocentesis.
What happens next in pregnancy?
Most women are offered a follow-up scan a few weeks later, and growth scans in the third trimester. These check:
- whether the brightness of the bowel has faded, which it often does
- your baby’s growth and the blood flow in the placenta and the baby
- whether any loops of bowel have become widened
- the amount of fluid around your baby.
If the tests are reassuring and your baby continues to grow well, no further special care is usually needed, and echogenic bowel does not change how or where you give birth.
What happens after birth?
Most babies need no special care after birth. Your baby will be checked by a paediatrician, who will make sure they are feeding well and opening their bowels normally in the first day or two. All babies in the UK are also offered the newborn blood spot test, which includes screening for cystic fibrosis.
If a specific cause was found during pregnancy, such as an infection or a bowel problem, a plan for your baby’s care after birth will be made with the paediatric team.
Frequently asked questions
Did I do something to cause this?
No. Echogenic bowel is not caused by anything you have eaten, drunk or done during pregnancy. If it is caused by swallowed blood after bleeding, this is not harmful to your baby.
Can echogenic bowel go away?
Yes. In many babies, the bowel looks less bright or normal on later scans.
Does it mean my baby has cystic fibrosis?
Most babies with echogenic bowel do not have cystic fibrosis. A simple test for both parents can show whether you carry a cystic fibrosis gene change. If neither parent is a carrier, cystic fibrosis is very unlikely.
Do I need an amniocentesis?
Not usually. It may be discussed if your earlier screening showed a higher chance, other markers are seen, both parents carry a cystic fibrosis gene change, or a recent infection is found.
Will my baby need treatment after birth?
Most babies do not. Your baby will be checked after birth to make sure they are feeding and opening their bowels normally.
Follow-up at The Pregnancy Clinic
At The Pregnancy Clinic in Sevenoaks, Kent, follow-up scans for echogenic bowel are carried out by fetal medicine specialists. Our approach includes:
- a detailed assessment of your baby’s bowel and anatomy, using standard settings
- a review of your earlier screening results and pregnancy history
- arranging blood tests for infection and cystic fibrosis carrier testing when needed
- assessment of your baby’s growth and the blood flow in the placenta and baby
- a clear explanation of the findings on the day, and a written report to share with your NHS maternity team.
Book a follow-up scan
If echogenic bowel was seen at your 20-week scan, a detailed scan with a fetal medicine specialist can assess your baby and plan any tests that are needed.
Book a detailed anomaly scan →The Pregnancy Clinic provides planned appointments only. If you have pain, bleeding, leaking fluid, reduced baby movements or any other urgent concern, please contact your local NHS maternity unit straight away, or call 999 in an emergency.
Related pregnancy guides
Clinical references
- D’Amico A, Buca D, Rizzo G, et al. Outcome of fetal echogenic bowel: a systematic review and meta-analysis. Prenat Diagn 2021;41:391–9
- Agathokleous M, Chaveeva P, Poon LC, Kosinski P, Nicolaides KH. Meta-analysis of second-trimester markers for trisomy 21. Ultrasound Obstet Gynecol 2013;41:247–61
- Al-Kouatly HB, Chasen ST, Streltzoff J, Chervenak FA. The clinical significance of fetal echogenic bowel. Am J Obstet Gynecol 2001;185:1035–8
- Ameratunga DM, Said JM, Reidy K, Palma-Dias R. Perinatal outcomes following the ultrasound diagnosis of echogenic bowel: an Australian perspective. Fetal Diagn Ther 2012;31:179–84
This guide provides general information and does not replace individual medical advice. Recommendations may vary according to your scan findings, pregnancy history and clinical circumstances.