Antenatal Steroids: Benefits and Risks Explained

Introduction

Antenatal steroids are a crucial intervention in modern pregnancy care, used to promote the development of a baby’s lungs and reduce complications associated with preterm birth. Administered to mothers who are at risk of delivering prematurely, these steroids help accelerate the development of vital organs, particularly the lungs, preparing the baby for survival outside the womb.

However, like all medical treatments, antenatal steroids come with both benefits and risks. In this article, we explore the science behind antenatal steroids, their advantages in antenatal care, the circumstances in which they are used, and the potential risks involved. Expectant parents, healthcare professionals, and those interested in prenatal care can gain valuable insights into this common yet critical treatment.

What Are Antenatal Steroids?

Antenatal steroids refer to corticosteroids, commonly dexamethasone or betamethasone, that are given to pregnant women who are at risk of preterm labour. These steroids are designed to speed up the development of the baby’s lungs, brain, and other organs, which may not yet be fully mature, especially if the baby is born prematurely.

1. How Antenatal Steroids Work

Antenatal steroids are usually given in the form of injections to the mother, typically over the course of 24 to 48 hours. The steroids cross the placenta, stimulating the baby’s liver to produce proteins that are essential for lung maturation. This process helps to prevent or reduce the incidence of respiratory distress syndrome (RDS), a common issue for premature babies. RDS occurs when a baby’s lungs are not developed enough to provide sufficient oxygen, often resulting in breathing difficulties.

By promoting lung development, antenatal steroids significantly improve the likelihood of survival and reduce the risk of long-term health problems in preterm infants. (American College of Obstetricians and Gynecologists, 2023)

The Benefits of Antenatal Steroids

1. Preventing Respiratory Distress Syndrome (RDS)

The primary benefit of administering antenatal steroids is the reduction in the incidence of respiratory distress syndrome (RDS), a condition that affects premature infants. By accelerating lung development, the steroids reduce the chances of RDS and its associated complications, such as the need for mechanical ventilation and prolonged hospitalisation.

A study by the World Health Organization (WHO) found that the use of antenatal steroids in pregnancies at risk for preterm birth decreased the risk of RDS by up to 50%. This means fewer babies experience the severe respiratory issues that often accompany premature birth. (World Health Organization, 2023)

2. Reducing Other Preterm Birth Complications

In addition to improving lung development, antenatal steroids help reduce the risk of several other complications associated with preterm birth, such as:

Intraventricular haemorrhage (IVH): Bleeding in the brain of premature infants.

Necrotising enterocolitis (NEC): A serious intestinal condition more common in premature infants.

Infections: Preterm babies are more vulnerable to infections due to an underdeveloped immune system.

Studies have shown that antenatal steroids not only improve survival rates but also contribute to better long-term health outcomes for premature infants. (Royal College of Obstetricians and Gynaecologists, 2023)

3. Improving Long-Term Development

While the immediate benefits of antenatal steroids focus on survival and reduced complications at birth, they also have long-term developmental benefits. Babies who receive antenatal steroids show improvements in cognitive, motor, and behavioural development. This is particularly significant in extreme preterm births, where the risk of developmental delays is typically higher.

Research indicates that antenatal steroids may also contribute to improved outcomes in preterm infants who are born after 32 weeks gestation, further cementing their role in promoting overall development. (National Institutes of Health, 2023)

The Risks of Antenatal Steroids

1. Potential Side Effects for Mothers

While antenatal steroids offer significant benefits to preterm babies, there are potential risks to the mother as well. These include:

Increased blood sugar levels: Corticosteroids can cause a rise in blood sugar, which may be a concern for women with gestational diabetes.

Infection risk: High doses of steroids can suppress the immune system, increasing the risk of infections, especially in mothers with preexisting conditions.

However, the side effects are typically short-lived and reversible once the medication is stopped. The benefits to the baby generally outweigh the potential risks to the mother. (American Pregnancy Association, 2023)

2. Potential Long-Term Effects on the Baby

Research into the long-term effects of antenatal steroids on babies is ongoing. Some studies have raised concerns about potential effects on development, including:

Increased risk of asthma or wheezing: Some research has suggested that babies born after antenatal steroid exposure may have a slightly higher risk of respiratory issues later in life.

Behavioural concerns: There have been reports of potential behavioural changes in children who were exposed to antenatal steroids in utero, though these effects are generally minor and not conclusive.

It is important to note that these risks are considered rare and typically less significant than the immediate benefits provided by the steroids, especially when administered appropriately. (Mayo Clinic, 2023)

When Are Antenatal Steroids Administered?

Antenatal steroids are typically recommended when a woman is at risk of delivering prematurely, specifically when the birth is expected to occur between 24 and 34 weeks of pregnancy. The steroids are usually given in the following circumstances:

Threatened preterm birth: When labour begins early, particularly between 24 and 34 weeks, and there is a chance of delivery in the near future.

Multiple pregnancies: In cases of twins or triplets, where premature birth is more likely due to the higher risk of early labour.

Preterm rupture of membranes: If the water breaks prematurely, increasing the likelihood of preterm labour.

The decision to administer antenatal steroids is made by healthcare providers based on the individual circumstances of the pregnancy, weighing the risks and benefits for both the mother and baby. (Royal College of Obstetricians and Gynaecologists, 2023)

Alternatives and Additional Treatments

While antenatal steroids are highly effective, they are not the only treatment available for premature birth. In some cases, additional treatments may be used to support both the mother and baby, including:

Tocolytics: Medications that help delay preterm labour, providing more time for the steroids to take effect and for the baby to develop.

Magnesium sulfate: Used to reduce the risk of cerebral palsy in preterm infants.

Antenatal antibiotics: Administered if there is a risk of infection due to premature rupture of membranes.

These treatments may be used in conjunction with antenatal steroids to provide the best possible outcomes for both mother and baby. (National Institutes of Health, 2023)

Conclusion

Antenatal steroids play a critical role in preventing complications associated with preterm birth, significantly improving the chances of survival and reducing the risk of developmental issues for premature infants. Their benefits are well-documented, especially when administered between 24 and 34 weeks of pregnancy.

However, as with any medical intervention, there are risks involved. Mothers and healthcare providers must carefully weigh the benefits of antenatal steroids against potential side effects, always ensuring that the health and safety of both mother and child are the top priority. Through careful monitoring, antenatal care, and informed decision-making, pregnant women at risk of preterm birth can give their babies the best possible start in life.