Treatment of Preterm Labor: NSAIDs Indomethacin

Written by the Healthline Editorial Team | Published on March 15, 2012
Medically Reviewed by Alison Stuebe, MD

What Is Indomethacin?

Non-steroidal anti-inflammatory drugs, or NSAIDs, include ibuprofen (Motrin) and indomethacin (Indocin). Indomethacin is the most frequently used NSAID for preterm labor. It can be given by mouth or by rectal suppository. It can be used alone or in combination with other tocolytics, like magnesium sulfate.

Indomethacin is particularly effective in the second and early third trimesters, and it may be useful in women who continue to have contractions after being given magnesium sulfate. In most circumstances, indomethacin should not be used for more than two to three days at a time.

How Does Indomethacin Work?

NSAIDs keep the body from making prostoglandins, substances which cause uterine contractions.

How Effective Is Indomethacin?

Indomethacin can reduce the number and frequency of contractions; however, this effect and how long it lasts varies from woman to woman. Like all tocolytic medications, however, indomethacin does not consistently prevent or delay preterm delivery for a significant period of time.

Even so, studies have shown that indomethacin can delay delivery for at least several days (depending on how far dilated a woman's cervix is when the medication is started). This isn't a lot of time, but it can make a big difference for the baby if the mother is given steroids along with indomethacin. After 48 hours, steroids improve a baby's lung function and reduce his or her risk of dying by 40%.

What Are the Possible Side Effects of Indomethacin?

For the Mother

Indomethacin causes indigestion in many women. This effect may be lessened by taking indomethacin with food or, if necessary, by also taking an antacid.

For the Baby

Indomethacin has two potentially serious side effects for the fetus. This drug can cause (1) a reduction in the amount of urine the fetus produces and (2) changes in the way the blood circulates through the fetus's body.

If the fetus makes less urine, the amount of amniotic fluid in the uterus may also be reduced, a condition known as oligohydramnios. The reduction in fluid seems to be most common when a mother is on indomethacin for more than two days. During this time, amniotic fluid levels should be checked regularly by ultrasound (a machine that uses sound waves to produce a picture of the inside of the body). Fortunately, the amount of amniotic fluid almost always returns to normal once indomethacin is discontinued.

Indomethacin can also cause a major blood vessel, the ductus arteriosus, to close prematurely. This can cause serious problems after the baby is born. Fortunately, the ductus does not close early if indomethacin is used for less than 48 hours. It's also less likely to be a problem before 32 weeks of pregnancy. If a mother takes the medicine for more than 2 days, it is useful to check an ultrasound of the baby's heart to make sure this blood vessel has not been affected.

Other side effects in the baby have been reported, but none have been consistently confirmed.

Are There Women Who Should Not Take Indomethacin?

Women who are more than 32 weeks pregnant should avoid indomethacin, given the potential for heart problems in the baby. Women with a history of ulcers, kidney, liver, or bleeding problems should also avoid indomethacin.

Was this article helpful? Yes No

Thank you.

Your message has been sent.

We're sorry, an error occurred.

We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later.

Trending Now

Easy Ways to Conceal an Epinephrine Shot
Easy Ways to Conceal an Epinephrine Shot
Learn how to discreetly carry your epinephrine autoinjectors safely and discreetly. It’s easier than you think to keep your shots on hand when you’re on the go.
Understanding the Progression of Ankylosing Spondylitis
Understanding the Progression of Ankylosing Spondylitis
One serious potential cause of back pain is ankylosing spondylitis. Get an understanding of what this condition is, how it progresses, and potential complications in this slideshow.
Common Asthma Triggers and How to Avoid Them
Common Asthma Triggers and How to Avoid Them
Learn about some of the most common triggers for asthma, as well as measures you can take to minimize your risk of exposure, symptoms, and flares.
Timeline of an Anaphylactic Reaction
Timeline of an Anaphylactic Reaction
From first exposure to life-threatening complications, learn how quickly an allergy attack can escalate and why it can become life threatening.
The Best Multiple Sclerosis iPhone and Android Apps of the Year
The Best Multiple Sclerosis iPhone and Android Apps of the Year
These best multiple sclerosis apps provide helpful information and tools to keep track of your symptoms, including medication reminders.