What Is Uterine Didelphys (Double Uterus)?

Medically Reviewed by Melinda Ratini, MS, DO on August 12, 2023
4 min read

Uterine didelphys is also known as a double uterus. It is an irregularity that happens before you’re born. Some women who have a double uterus also have a double bladder, urethra, and anus.

Uterine didelphys is a rare condition that happens when you grow two uteruses instead of one. This happens when you are a developing baby. You are born with it. 

While developing as babies, girls typically grow a uterus from two channels called the Mullerian ducts. These channels join together and make one hollow organ called the uterus. In uterine didelphys, the channels don’t properly join together. Each tube can turn into a uterus, causing you to develop two. 

Some women with uterine didelphys also have two cervixes — or openings to the vagina — and a thin wall of tissue down the vagina that creates two vaginas.

Sex organs develop when a baby is between 6 weeks to 22 weeks during pregnancy, and a double uterus forms because of failure for the tubes to join. It’s not exactly clear why some babies develop two uteruses, but it might be linked with some genetic conditions.

Some babies who only grow one kidney can have irregular sex organs. Uterine didelphys can also happen with some rare conditions and other irregularities, including:

  • Herlyn-Werner-Wunderlich syndrome, which is when you have rare Mullerian duct anomalies. It may cause pelvic pain and cause one side of a double vagina to be blocked.
  • Cervical agenesis, where you’re born without a cervix
  • Small kidneys
  • Congenital vesicovaginal fistula, a serious disability where there’s a hole between the vagina and the bladder that causes leaking urine
  • Bladder exstrophy, where the bladder grows outside of your body in the womb
  • Vaginal agenesis, where you’re born without a vagina

The exact cause is unknown.

Lots of women don’t know they have uterine didelphys and it is sometimes only found during a routine pelvic exam or ultrasound. 

Some women go to the doctor because of uncontrollable bleeding when they’re using a tampon. This happens when the tampon is inserted in one vagina but the bleeding still comes from the other uterus and vagina. 

You can have other symptoms like:

Your doctor might find a double uterus during your routine pelvic exam. This may be when you get a pap smear or if you're having menstrual or pregnancy problems and your doctor does an exam.

If your doctor thinks there is an irregularity, they might order some imaging tests.

These can include:

  • Magnetic resonance imaging. Also called an MRI, this test uses a magnetic field and radio waves to create images of the inside of your body. 
  • Hysterosalpingography. During this test, a special dye is inserted into your uterus through your cervix. X-rays are taken to follow the dye as it moves through your organs and to see the shape and size.
  • Ultrasound. Using high-frequency sound waves, images are taken of your uterus. This may be done with a wand against your abdomen or inserted into your vagina. 
  • Sonohysterogram. A special dye is put into your uterus through your cervix and an ultrasound is used to get pictures of your uterus. The dye helps show the size and shape.

If you don’t have any symptoms, you might not need any treatment for uterine didelphys. 

Lots of women with two uteruses have normal sex lives, pregnancies, and births. Sometimes surgery might be done if you have repeated pregnancy losses. The surgery involves attaching the two channels to form one uterus. 

If you have a double vagina, your doctor might remove the tissue between them to make one vagina. This can help with birth.

Women with a double uterus can usually get pregnant. It’s possible to carry your baby to full term, but with uterine didelphys, you have a greater risk of pregnancy complications.

These complications can include:

  • Repeated pregnancy loss
  • Early labor
  • Torn vaginal tissue between the two vaginas during labor
  • Breech baby (facing feet first) who needs a C-section delivery
  • Low birth weight
  • Intrauterine growth restriction
  • Kidney problems

Some doctors disagree about whether women who have uterine didelphys should have a vaginal delivery or a C-section. The researchers of one review show that vaginal delivery is possible but feel that a C-section might be the safest.

Uterine didelphys is also linked with some other conditions like endometriosis. This condition happens when tissue similar to the uterus lining tissue called endometrium grows outside of the uterus but still responds to hormones. This tissue breaks down and bleeds as normal but has no escape, which causes lots of pain.

Uterine didelphys is a sexual organ irregularity that happens before birth. It can cause problems with pregnancy and delivery, and pain and heavy bleeding during menstruation, but lots of women never have any symptoms. 

If you have uterine didelphys and plan to have a baby, talk to your doctor about your condition so they can help you have the safest pregnancy.