Medications for Preterm Labor and Delivery

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

  1. Tocolytics—to slow or stop 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 or treat 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. They are currently given for 48 hours to delay delivery of the baby. 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 specialty 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 by IV. 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 1 baby.



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Last reviewed March 2018 by EBSCO Medical Review Board Beverly Siegal, MD, FACOG
Last Updated: 4/6/2016

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