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If you are having preterm labor, you may be given medication. This may include:

  1. Tocolytics—to delay labor .
    1. Calcium channel blockers
    2. Betamimetics
    3. Prostaglandin synthetase inhibitors (cyclooxygenase inhibitors)
    4. Magnesium sulfate—may also be given to promote brain development in the fetus
    5. Antibiotics—to treat infection in the mother (which may slow or stop premature labor)
  2. Antibiotics—to prevent infection in the mother and baby
  3. Progesterone (given vaginally or by injection)—to prevent premature birth
  4. Dexamethasone or betamethasone—to mature the babies lungs if premature birth happens

Tocolytics are drugs that minimize the strength and number of contractions. Although an ideal goal would be to stop preterm labor completely, the most that can be reasonably expected from current tocolytics is a delay of 48 hours. This delay allows time for treatment with steroids and antibiotics. Steroids are given to speed the baby’s lung development. Even a few extra days in the uterus can be vital to the baby’s development.

Antibiotics may be given to treat a suspected infection. During this time, you may also be transferred to a better-equipped hospital.

These drugs can be given through an IV or by mouth between 24 and 34 weeks gestation.

Calcium Channel Blockers
  • Common name: Nifedipine

Calcium channel blockers reduce smooth muscle contractions, such as those in the uterus. In addition, statistically significant benefit has been seen for infants in terms of preventing respiratory distress syndrome , necrotizing enterocolitis , intraventricular hemorrhage, and jaundice .

Prostaglandin Synthetase Inhibitors (Cyclooxygenase Inhibitors)

Common names include:

  • Ibuprofen
  • Indomethacin
  • Ketorolac
  • Sulindac

Prostaglandins cause uterine contractions, so these drugs are meant to block the production of prostaglandin and may be used in certain causes of preterm contractions.


Common names include:

  • Terbutaline
  • Ritodrine

These drugs cause uterine muscles to relax.

Magnesium Sulfate

This is a muscle relaxant that is given intravenously. While this medication has not been proven to delay preterm birth, it is effective in treating pre-eclampsia and does offer protection against brain injury in the baby. It is used frequently in the presence of preterm labor.


Common names include:

  • Betamethasone
  • Dexamethasone

If you are between 24-34 weeks of pregnancy, your doctor may give corticosteroids. These drugs help your baby’s lungs mature. They also reduce the risk of respiratory distress syndrome and bleeding in the brain. With these drugs, your baby will breathe easier after delivery.


Common names include:

  • Penicillin
  • Ampicillin
  • Clindamycin
  • Vancomycin
  • Cefazolin

Antibiotics help to treat and prevent infection in both the mother and the baby. Preterm babies are at increased risk of infection because their immune systems are immature.


Also known as hydroxyprogesterone.

Progesterone is a hormone made by the body. It helps the uterus grow and keeps it from having contractions. Progesterone treatment may help reduce your risk for premature birth if you have had a premature birth in the past or have a short cervix, and are pregnant with just one baby.


ACOG Committee Opinion No. 291: Use of progesterone to reduce preterm birth. American College of Obstetricians and Gynecologists. 2003.

Berghella V, Klebanoff M, et al. National Institute for Child Health and Development Maternal Fetal Medicine Units Network. Sexual intercourse association with asymptomatic bacterial vaginosis and trichomonas vaginalis treatment in relationship to preterm birth Am J Obstet Gynecol. 2002;187:1277-1282.

Dodd JM, Crowther CA, et al. Progesterone supplementation for preventing preterm birth: a systematic review and meta-analysis. Acta Obstet Gynecol Scand. 2005;84:526-533.

MacKenzie R, Walker M, et al. Progesterone for the prevention of preterm birth among women at increased risk: A systematic review and meta-analysis of randomized controlled trials. Am J Obst Gynecol. 2006;194:1234-1242.

McDonald H, Brocklehurst P, Parsons J. Antibiotics for treating bacterial vaginosis in pregnancy. The Cochrane Database of Systematic Reviews. 2005;(1):CD000262.

Ness A, Dias T, et al. Impact of the recent randomized trials on the use of progesterone to prevent preterm birth: a 2005 follow-up survey. Am J Obstet Gynecol. 2006;195:1174-1179.

Prevention of preterm labor and preterm birth. EBSCO DynaMed Plus website. Available at: Updated September 10, 2016. Accessed October 6, 2016.

Preterm labor. EBSCO DynaMed Plus website. Available at: Updated August 19, 2016 . Accessed October 6, 2016.

Stanley FJ, Crowther C. Antenatal magnesium sulfate for neuroprotection before preterm birth? N Engl J Med. 2008; 359:962-964.

Treatments for preterm labor. March of Dimes website. Available at: Updated July 2014. Accessed April 6, 2016.

What treatments can reduce the chances of preterm labor & birth? National Institute of Child Health & Human Development website. Available at: Updated November 6, 2013. Accessed March 18, 2014.

Whitworth M, Quenby S; Cochrane Pregnancy and Childbirth Group. Prophylactic oral betamimetics for preventing preterm labour in singleton pregnancies. The Cochrane Database of Systematic Reviews. 2009; (1).

Yemini M, Borenstein R, et al. Prevention of premature labor by 17 alpha-hydroxyprogesterone caproate. Am J Obstet Gynecol. 1985;151:574-577.

Last reviewed March 2017 by EBSCO Medical Review Board Andrea Chisholm, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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