Congenital uterine anomalies (CUAs) 



MA Akhtar, SH Saravelos, TC Li, K Jayaprakasan, on behalf of the Royal College of Obstetricians and Gynaecologists

Congenital uterine anomalies (CUAs) are malformations of the womb that develop during fetal life. When a baby girl is in her mother’s womb, her womb develops as two separate halves from two tubular structures called ‘Müllerian ducts’, which fuse together before she is born. Abnormalities that occur during the baby’s development can be variable from complete absence of a womb through to more subtle anomalies, which are classified into specific categories. While conventional ultrasound is good in screening for CUAs, 3D ultrasound is used to confirm a diagnosis. If a complex womb abnormality is suspected, MRI scanning may also be used, with a combination of laparoscopy in which a camera is inserted into the cavity of the abdomen, and hysteroscopy, when the camera is placed in the womb cavity. As there can be a link between CUAs and abnormalities of the kidney and bladder, scans of these organs are also usually requested. 


What are congenital uterine anomalies? 

Uterine anomalies are malformations of the uterus that develop during embryonic life. Uterine anomalies occur in less than 5% of all women but have been noted in up to 25% of women who have had miscarriages and/or deliveries of premature babies. When a woman is in her mother’s womb, her uterus develops as two separate halves that fuse together before she is born. When a woman's uterus develops differently from most women, it is called a uterine anomaly or abnormality. 

Uterine Anomality  

  • Bicornate uterus (also called heart-shaped uterus). This is when the uterus has two separate spaces instead of one large space.  
  • Didelphys uterus (also called double uterus). This is when there are two small, separate spaces, each with its own cervix (opening). 
  • Septate uterus. This uterine anomality is most common. In this condition, a band of muscle or tissue divides the uterus into two spaces. This condition can cause women to have repeat miscarriages, so doctors will often recommend surgery to repair the uterus and reduce your risk of miscarriage.  
  • Unicornuate uterus (also called one-sided uterus). This condition happens when only half the uterus forms. Surgery will not be able to correct this abnormality. 

Do these anomalies symptomatic? 

Although congenital uterine anomalies are present at birth, these malformations are usually don’t prompt women with symptoms that this is a problem. Some women may have pain with their menstrual periods. Congenital uterine anomalies typically do not cause a woman to have difficulty getting pregnant. However, these malformations are often discovered during evaluations for infertility or miscarriages. 

How are congenital uterine anomalies diagnosed? 

A complete medical history and physical examination could possibly prompt a obstetrician or gynaecologists to a congenital uterine anomaly. However, imaging studies, such as a hysterosalpingogram and ultrasound, or an MRI, will help to diagnosis a uterus problem and confirm that a uterine anomaly is present. 


How are congenital uterine anomalies treated? 

There are no non-surgical treatments for congenital uterine anomalies. Surgical treatment of uterine abnormalities depends on the particular problem and the woman’s reproductive history. If a septate uterus is diagnosed for infertility and/or pregnancy loss, surgical treatment may be advised. Bicornuate, unicornuate and didelphic uteri rarely require surgical treatment. Congenital uterine anomalies may increase the likelihood that a woman will have a miscarriage or a premature delivery. If a woman has a septate uterus and has had miscarriages, surgical treatment may improve her chances for a successful pregnancy. 

If you know you have an abnormally shaped uterus, you may feel anxious during your pregnancy, especially if you’ve had a previous miscarriage. Going to every antenatal appointment will help be empowered with the information that will help this pregnancy move forward. Having close care from your midwife and doctor gives you the best chance of having a successful pregnancy.  

Understanding the signs and symptoms of premature labour. Then if your baby starts coming too soon, you’ll know what’s happening and can get to hospital quickly.  

Signs and symptoms of Preterm Labour Include: 

  • Regular or frequent sensations of abdominal tightening (contractions) 
  • Constant low, dull backache 
  • A sensation of pelvic or lower abdominal pressure 
  • Mild abdominal cramps 
  • Vaginal spotting or light bleeding 
  • Preterm rupture of membranes — in a gush or a continuous trickle of fluid after the membrane around the baby breaks or tears 
  • A change in type of vaginal discharge — watery, mucus-like or bloody

If at any time you feel that something is wrong, contact your midwife or doctor immediately. Don't worry about raising a false alarm. Your caregiver will be happy to check you and your baby and reassure you. 

Useful Links 

COPE – Centre for Perinatal Excellence 

Panda - Perinatal Mental Health

Through the unexpected

Confirmation Content

Disclaimer: This publication by Miracle Babies Foundation is intended solely for general education and assistance and it is it is not medical advice or a healthcare recommendation. It should not be used for the purpose of medical diagnosis or treatment for any individual condition. This publication has been developed by our Parent Advisory Team (all who are parents of premature and sick babies) and has been reviewed and approved by a Clinical Advisory Team. This publication is not a substitute for professional medical advice. Miracle Babies Foundation recommends that professional medical advice and services be sought out from a qualified healthcare provider familiar with your personal circumstances.To the extent permitted by law, Miracle Babies Foundation excludes and disclaims any liability of any kind (directly or indirectly arising) to any reader of this publication who acts or does not act in reliance wholly or partly on the content of this general publication. If you would like to provide any feedback on the information please email [email protected].