Ever wonder what your uterus gets up to during pregnancy?
Apart from stretching with your growing baby, what else is it doing?
You might have heard of Braxton Hicks contractions, also known as ‘practice contractions’.
Unlike regular contractions, Braxton Hicks are usually irregular and quite mild. They stop after a while, particularly if you rest or hydrate.
However, some women experience what’s known as an irritable uterus (IU) in pregnancy.
This is when the uterus contracts during pregnancy but isn’t actually labor.
Here is some information about exactly what an irritable uterus is, and whether there is a treatment.
What is a uterus?
The uterus is a powerhouse of muscle layers. During pregnancy, the inner horizontal layer of muscles keeps the cervix closed.
The outer vertical muscle layer contracts when labor begins, opening the cervix and pushing the baby out.
You can read more about this in What Your Uterus Does In Labor.
What is irritable uterus?
Irritable uterus is when the uterus contracts in pregnancy, without acting on the cervix.
The contractions are like Braxton Hicks but they’re regular and don’t go away if you have a drink or rest.
Irritable uterus contractions aren’t like regular labor contractions.
Labor contractions are regular and strong.
Very few studies have been done to investigate IU in pregnancy, so we don’t really know what causes it.
However, from what women report about it, we know there are some common triggers:
- Lifting heavy objects
- Having an orgasm
- A full bladder
- Urinary tract infection
- Excessive fetal movement.
Preterm labor is thought to be caused by an irritable uterus.
Irritable uterus vs prodromal labor
Irritable uterus can be confused with prodromal labor, but they’re not the same thing.
Prodromal labor is also known as false labor. It usually happens after 37 weeks and is the lead-up to actual labor. The contractions are stronger than irritable uterus contractions.
It’s most common in a woman’s first pregnancy, but doesn’t happen for every woman.
Prodromal comes from the Greek word prodromos, which means ‘running before’.
It’s an excellent explanation for this form of labor, which occurs hours, days or weeks before real active labor starts.
In other words, it’s an early sign your body is preparing for the real thing.
Prodromal labor can be frustrating but it isn’t harmful to you or your baby, so there’s no need to be concerned.
What does irritable uterus feel like?
Irritable uterus has been described as feeling like menstrual cramps that occur frequently and are regular in length and timing.
They can feel similar to Braxton Hicks contractions with a bit more bite.
Due to the intensity of the contractions, women with uterine irritability often mistake them for the real thing.
The tightenings can also be accompanied by a feeling of pressure and/or pain in the back.
Unlike Braxton Hicks contractions, irritable uterus contractions worsen with increased activity.
IU can also feel like a constant tight belly, which gets worse when standing or walking.
In many women, the tight belly can last for over an hour at a time.
How to diagnose irritable uterus
If you’re experiencing contractions before 37 weeks, your health care provider will run some tests to see what’s happening.
First, your doctor will monitor your contractions. This is done by putting a special belt around your belly to measure the strength, length, and duration of the contractions.
It also measures your baby’s heart rate, to see how your baby is coping.
Your doctor might also order other tests to see if you’re at risk of preterm labor.
These tests include:
- Fetal fibronectin test. A sample of vaginal secretions is tested for a protein that attaches the amniotic sac to the uterus. If the test comes back positive, it means you’re at risk for preterm labor. But it’s not a guarantee that you will give birth early.
- Ultrasound, to check the length of your cervix, which begins to shorten and thin when contractions are actively working to dilate the cervix.
Management for irritable uterus
Dealing with uterine irritability can be very challenging.
It can interrupt your sleep and make you feel on edge about preterm labor. This can all add to your exhaustion.
If you’re having a lot of contractions, your doctor might recommend bed rest or admit you to the hospital.
Your doctor may prescribe medicine if nothing else appears to be helping your IU. Nifedipine (Procardia) and hydroxyzine (Vistaril) are two medicines that can help with contractions.
Because we don’t know what causes an irritable uterus, it’s hard to know the best treatment.
How can I relax my uterus?
You can try placing one hand on your chest and the other on your abdomen, just below your rib cage.
Inhale deeply to the count of three, then exhale slowly to the count of four. Your pelvic floor relaxes as you inhale and returns to its resting position as you exhale. This can encourage your uterus to relax and stop contracting.
Other ways to avoid triggering irritable uterus contractions:
- Keep your bladder empty; a full bladder can create further irritation
- Stay hydrated
- Reduce your stress levels
- Get plenty of sleep
- Avoid lifting heavy items
- Lie on your left side
- Eat small meals, more frequently
- Avoid caffeine
- Take magnesium supplements, but first check with your health care provider, to see whether you have a deficiency.
If the uterine irritability is severe, your doctor might prescribe medication to prevent or reduce the intensity of the contractions.
Magnesium sulfate is commonly given to women to help settle an irritable uterus.
You can also include in your diet foods with high magnesium content, such as dark chocolate, fatty fish, avocado, nuts, tofu, legumes, and whole grains.
Can irritable uterus lead to bed rest?
If your doctor believes you to be at increased risk of preterm birth, you could be put on bed rest.
Bed rest might be:
- Total bed rest, when you spend almost all of your time in bed
- Partial bed rest, when you spend an extra four hours a day resting in bed
- Pelvic rest, which means no sexual activity, including masturbation.
Is irritable uterus a risk factor for preterm birth?
It’s generally believed uterine irritability increases the chances women will give birth earlier than 37 weeks.
Research looking into this link is quite old, dating from 1995. This research article found preterm labor was more likely to be linked to other high-risk factors, but the data also showed almost 19% of women with uterine irritability experienced preterm labor.
Unfortunately, there haven’t been further studies to investigate this link and so the reason for the increased risk remains unknown.
Irritable uterus – when to go to hospital
When you should seek medical assistance with an irritable uterus depends on how many weeks pregnant you are.
There is a big difference between a pregnant woman experiencing irritable uterus at 28 weeks, compared with 37 weeks.
At 37 weeks, your baby is no longer premature, but mature and able to cope with the transition to life outside the womb.
Before this time, your baby is at risk of complications such as breathing difficulties.
You should seek medical advice if you experience any of the following:
- Painful contractions, contractions every 5-10 minutes, or more than five contractions in an hour
- Any vaginal bleeding or leaking from the vagina
- Reduced fetal movements or differences from your baby’s normal pattern of movements
- Pressure in the pelvis or vagina
- Regular lower back pain.
If you have any concerns about these symptoms, or about how you are feeling generally, don’t hesitate to speak to your midwife or doctor immediately.
It’s important to be assessed in case you are at risk of preterm labor, so you and your baby can get the appropriate management.
If you are suffering from IU, you are probably feeling quite frustrated by the lack of information available about your condition.
Experiencing an irritable uterus can be confusing and exhausting so be sure to reach out for help from your health provider, family, and friends.
Try to relax, and get as much rest as you can. If you find something that reduces the contractions, keep doing it!