If you’re newly diagnosed with a unicornuate uterus, you may have lots of questions — including why no one ever mentioned it to you before.
A unicornuate uterus is a genetic condition that causes only half of your uterus to form. As a result, you may have a single fallopian tube instead of two and a uterus that’s usually smaller in size.
This all sounds pretty noticeable, but often, you don’t find out about it until you start trying to conceive and possibly have difficulty getting pregnant.
Let’s look at:
- what you need to know about this rare condition
- how it can affect your ability to conceive
- how the obstacles you may be facing can be overcome
A unicornuate uterus can affect your ability to get pregnant and to carry a pregnancy to term.
Some of the known side effects include:
- breech pregnancy
- increased risk for a cesarean delivery
- increased risk for placenta previa and placental abruption
- intrauterine growth restriction
- preterm birth
- preterm premature rupture of membranes
Per a 2014 case report, here are some statistics relevant to having a unicornuate uterus (but remember — you’re not defined by statistics):
- live birth rate: 29.2 percent
- ectopic pregnancy rate: 4 percent
- prematurity rate: 44 percent
Because a unicornuate uterus is so rare, there are some things healthcare providers don’t know about how much it affects fertility, which can be frustrating.
A 2018 study compares success rates for in vitro fertilization (IVF) in women with a unicornuate uterus and those with a “normal” uterus.
(We use that term loosely. Uteruses — like women — come in all shapes and sizes.)
After completing one IVF cycle, 53.1 percent of women with a unicornuate uterus became pregnant compared to 65.7 percent of the control group.
The researchers interpreted this to mean people with a unicornuate uterus have a harder time getting pregnant. But there are still questions about why this is the case.
Before reading more about the data on women with unicornuate uterus and miscarriage, it’s important to remember there isn’t a lot of research. The condition is rare, so most studies and case reports are small.
Many studies do seem to reveal a greater risk for miscarriage. However, women with a unicornuate uterus can and do have successful pregnancies.
Healthcare providers have several theories about why a unicornuate uterus may increase the risk for miscarriage.
First, the blood flow to the uterus is reduced. A uterus typically has two arteries supplying blood to it. A unicornuate uterus usually has only one. This effect can increase the risk for first-trimester miscarriage.
Second, a unicornuate uterus is usually smaller in size and less able to accommodate a growing baby. This effect can increase the risk for second-trimester miscarriage.
Women with a unicornuate uterus also often experience problems with the cervix. The cervix can start to thin and dilate long before it’s time to deliver. This can lead to preterm delivery.
Research estimates 2.4 to 13 percent of all female reproductive tract abnormalities are due to a unicornuate uterus. That may sound pretty high, but only about 0.1 percent of women have a unicornuate uterus.
Unfortunately, healthcare providers don’t know why some women have this abnormality.
So far, they haven’t identified any ways to prevent this from occurring or potential risk factors. It’s simply something that seems to spontaneously happen. Most importantly, there’s nothing that you did to cause it.
You may have just found out about this condition and be here because you’ve been trying to get pregnant. If so, you’ve probably lived your life without symptoms other than having difficulty conceiving or experiencing one or more miscarriages.
But some women do have symptoms earlier.
Symptoms can include:
- chronic pelvic pain
- painful periods
You may also learn about your condition through an imaging test — like an ultrasound — for another medical issue.
Sometimes, people with a unicornuate uterus also have a second, smaller development of uterine tissue. Healthcare providers call this a hemi-uterus.
Because the hemi-uterus isn’t connected to the rest of the uterus, menstrual blood can’t exit. This can result in pelvic pain, especially around the time of your period.
If you have symptoms, a healthcare provider will first request a health history and do a physical exam. They’ll likely also perform a pelvic exam to rule out other potential causes.
The healthcare provider may also recommend imaging studies. These include a pelvic ultrasound or MRI scan.
Sometimes, the healthcare provider may recommend a surgical procedure called a laparoscopy.
This procedure involves using small keyhole incisions to insert small instruments with lights and cameras to look inside the abdomen. (This sounds super invasive, but it’s actually very routine.)
The procedure allows your healthcare provider to see the pelvic organs, including the uterus. By seeing the uterus, they can tell if it’s smaller in size and if a fallopian tube is missing.
If your healthcare provider finds a hemi-uterus, they’ll usually recommend surgical removal of it.
This is because it’s possible a pregnancy could start there, but it wouldn’t be viable — which can be very challenging situation to deal with when you’re trying to have a baby.
Since this area is much smaller and doesn’t have a place for the embryo to exit, the hemi-uterus could rupture. That would be potentially life-threatening.
If you become pregnant — and this is very possible either naturally or with reproductive assistance — your healthcare provider may recommend more frequent visits and ultrasounds to monitor the baby’s growth.
(Silver lining: You get to see your baby more often.)
Your healthcare provider may also want you to have a cervical cerclage or placement of a cervical ring or pessary if you have cervical shortening. This may help to reduce the risk for miscarriage.
Your healthcare provider may also prescribe certain medications — known as tocolytics — to reduce the likelihood that preterm delivery will occur. Tocolytics relax the uterus and reduce preterm labor contractions.
If you have painful periods or chronic pelvic pain, talk to your healthcare provider. If you’ve tried to conceive for a year and haven’t yet gotten pregnant, you should also see your healthcare provider.
Sometimes, you may know you have a unicornuate uterus before trying to conceive.
Talk to your OB-GYN about your specific type, because there are several variations. Your healthcare provider can discuss the data on successful pregnancies and cesarean deliveries given your specific type.
While it isn’t always possible to prevent miscarriage or preterm birth, there are steps you and your provider can take to help reduce the risks.
Difficulty conceiving or experiencing a miscarriage due to a unicornuate uterus can be devastating. You may blame yourself, even though it isn’t your fault.
These feelings are normal, but that doesn’t mean you need to go it alone. Ask your healthcare provider about local support groups for those who have experienced pregnancy loss or infertility.
Several national organizations also offer online support groups and resources for both you and your partner. RESOLVE, the national infertility association, is one example.
Some people may also choose to participate in individual or couple’s therapy.
This approach can be very healing for those working through the roller coaster of emotions that can accompany infertility and pregnancy loss.
A unicornuate uterus is a rare occurrence that can affect the ability to conceive and to carry a baby to term. While it may be more difficult, it’s not impossible to have a baby with this condition.
We live in a marvelous day and age where reproductive technology helps people conceive every day. If you’re having trouble getting pregnant, talk to your healthcare provider about your options.
Being empowered with information about your diagnosis can help lead to a successful 9 months of pregnancy. Work with your healthcare provider to ensure you have the best possible chance for a full-term delivery.