Magnesium for Preterm Labor: Does it Work?

Doctors have long been searching for ways to prevent preterm birth. But right now, they don’t fully understand why it happens. So there isn’t one 100% reliable method of preventing or stopping it. Some doctors administer magnesium for preterm labor. But how effective is it? Can magnesium delay labor, or even stop it altogether?

We’ll answer those questions and more below. 

Woman receives treatment for preterm labor.

What is Magnesium Sulfate?

Magnesium sulfate is a mineral compound that contains magnesium, sulfur, and oxygen. One of the primary uses of magnesium sulfate during pregnancy is to treat preterm labor.

When a woman goes into preterm labor (before 37 weeks of pregnancy), it can be risky for the baby’s health. The baby may not be fully developed to handle life outside the womb.

This is why doctors administer tocolytics, which are medicines that slow contractions, to mothers who may give birth too soon. Magnesium sulfate is one of the most commonly used tocolytics in the U.S. 

Studies have shown that magnesium can help slow contractions by reducing the amount of calcium in uterine muscles. This has a relaxing effect. It can lessen the intensity and frequency of contractions.

Can Magnesium Delay Labor?

You may have heard that doctors sometimes prescribe magnesium to stop contractions. But does it really work?

The answer is yes–and no. Magnesium sulfate can delay or slow down labor, but not for a long period of time. It delays labor for just a few days. It can’t prevent labor from happening. 

But even a short delay buys the medical team more time to administer other treatments or interventions. For example, they can give the mother steroids to help the baby’s lungs mature. Or they might transfer the mother to a hospital better equipped to care for premature infants.

Because of this, magnesium sulfate has the potential to reduce a fetus’ risk of dying or developing brain injuries related to preterm birth, such as:

Note that the magnesium we’re talking about isn’t the kind you take from a vitamin bottle (oral magnesium supplementation). Magnesium sulfate is only given intravenously. The medical team must take care to provide the correct dosage and monitor the patient constantly. 

IV drip of magnesium sulfate.

Correct Dosage of Magnesium for Preterm Labor

Magnesium sulfate isn’t considered a dangerous drug. But any drug can be dangerous if a doctor mishandles it. An overdose of magnesium can cause respiratory arrest. But this won’t happen when the doctor administers it within safe dose ranges. 

A typical magnesium regimen includes: 

  • An initial dose of 4 to 6 grams 
  • 1 to 3 grams maintenance doses every hour, for no longer than 7 days

Who Should Not Take Magnesium to Stop Contractions?

Magnesium sulfate doesn’t have the same effect on all women. For some, it may suppress labor for only 48 hours or less. It depends on how a woman’s body responds to it. Also, some women should not take magnesium for preterm labor, such as those with:

  • Certain heart problems
  • A muscle disorder called myasthenia gravis 
  • Muscular dystrophy
  • Kidney function impairment
  • Any other medical condition that gets worse when taking magnesium sulfate

Other Benefits of Magnesium Sulfate

Unfortunately, taking magnesium for preterm labor won’t stop a baby from being born preterm. It only slows contracts temporarily. 

But studies have also shown it has two other important benefits:

  • It’s effective for treating women with preeclampsia
  • It can protect a preterm baby’s brain

Why does magnesium sulfate have the potential to protect a baby’s brain? The main reason why is that it has the ability to cross the placenta and enter the fetal bloodstream. Studies have shown it can:

  • Reduce excitotoxicity (A condition in which excessive levels of certain chemicals in the brain overstimulate nerve cells and damage them.)
  • Reduce inflammation in the brain.
  • Relax blood vessels and improve blood flow to the brain.
  • Protect the brain cells from oxidative stress, which can damage them.
  • Stabilize blood pressure.
Legal help for birth injury.

Legal Help for a Mismanaged Premature Birth

No one (and no medication) can prevent premature birth. But your medical team is obligated to do their best to manage it. 

Part of that management includes proper monitoring and administering medications that can improve outcomes for your premature baby. Your doctor may prescribe medications like magnesium for preterm labor, as long as its benefits outweigh any risks to your health. 

Mismanaged premature birth can have devastating results. Preemies can end up with cerebral palsy, HIE, and other birth injuries because of negligence. 

We have helped countless families hold negligent doctors accountable and recover damages to pay for their children’s care. Contact our expert lawyers to find out if we can do the same for you.