Understanding Antenatal Steroids: Timing, Dosage, and Effects

Introduction

Antenatal steroids are an important intervention in the management of preterm labour, helping to reduce complications in preterm infants. They play a vital role in promoting the maturity of the baby’s lungs, which are often underdeveloped in premature births. Expectant parents may have many questions about antenatal steroids—from their purpose to when and how they are administered. This article answers the most frequently asked questions (FAQs) to help you better understand the role of antenatal steroids in pregnancy care.

This guide will cover essential information on the benefits, risks, timing, and dosage of antenatal steroids, alongside useful insights into antenatal care and how various other pregnancy interventions, such as antenatal yoga and prenatal massage, support the well-being of both mother and baby.

What Are Antenatal Steroids?

Antenatal steroids are corticosteroids (usually betamethasone or dexamethasone) that are given to pregnant women at risk of preterm birth. These medications accelerate the maturation of the fetus’s lungs, primarily by stimulating the production of surfactant. Surfactant is a substance that prevents the lungs’ tiny air sacs from collapsing, enabling effective breathing after birth.

Preterm infants, especially those born before 32 weeks of gestation, often have underdeveloped lungs, making it difficult for them to breathe on their own. By administering antenatal steroids, healthcare providers can increase the likelihood that the infant will be able to breathe independently after birth, reducing the risk of respiratory distress syndrome (RDS) and other complications.

Why Are Antenatal Steroids Used?

Antenatal steroids are most commonly used in pregnancies at risk of preterm birth, particularly between 24 and 34 weeks of gestation. The benefits of antenatal steroids are most pronounced in the prevention of respiratory distress syndrome (RDS), a condition in which a lack of surfactant causes breathing difficulties. By accelerating lung maturation, antenatal steroids also help reduce the incidence of other preterm birth complications such as intraventricular haemorrhage (IVH) and necrotising enterocolitis (NEC).

Antenatal steroids are given in cases where there is a high risk of preterm labour, including:

Multiple pregnancies (twins, triplets): These pregnancies are more likely to result in preterm birth.

Preterm premature rupture of membranes (PPROM): When the membranes rupture before 37 weeks of gestation.

Signs of preterm labour: Such as regular contractions, cervical changes, or other symptoms suggesting labour may occur prematurely.

Pregnancies at risk due to maternal health issues: Such as gestational hypertension or diabetes that may increase the risk of early delivery.

In these situations, antenatal steroids can improve neonatal outcomes significantly by promoting lung and organ development before birth. (Royal College of Obstetricians and Gynaecologists, 2023)

When Are Antenatal Steroids Administered?

Antenatal steroids are typically administered when preterm birth is expected to occur or when preterm labour is suspected. The optimal timing for the administration of antenatal steroids is between 24 and 34 weeks of gestation, although they may be used later in some circumstances if preterm birth is imminent. The aim is to give the steroids within 24 to 48 hours before birth to allow the medication to take effect and maximise the benefits to the baby.

Antenatal steroids are usually given in two doses: one dose immediately and another 24 hours later. The effects of antenatal steroids begin within 24 hours, although full benefits may take up to 48 hours to be realised.

If a woman is at risk of delivering at 34 weeks or later, the need for antenatal steroids may be less urgent, as fetal lung maturity improves after 34 weeks, reducing the likelihood of complications like RDS. (American College of Obstetricians and Gynecologists, 2023)

What Is the Dosage of Antenatal Steroids?

The recommended dosage of antenatal steroids depends on the specific corticosteroid used. There are two main types used in clinical practice: betamethasone and dexamethasone.

Betamethasone is typically given as 12 mg intramuscularly (IM) every 24 hours for two doses, totalling 24 mg.

Dexamethasone is given as 6 mg IM every 12 hours for four doses, totalling 24 mg.

The injections are generally administered in the gluteal muscle and are safe for both the mother and the fetus when used according to medical guidelines. The effects of antenatal steroids are typically seen within 24 hours and can last for up to a week. (Mayo Clinic, 2023)

What Are the Benefits of Antenatal Steroids?

1. Improved Lung Function

The primary benefit of antenatal steroids is the promotion of lung maturity in preterm infants. The steroids help the fetus produce surfactant, a critical substance that helps the lungs expand properly and prevents air sacs from collapsing. This increases the chances that preterm infants will be able to breathe on their own after birth, reducing the need for mechanical ventilation and decreasing the risk of respiratory distress syndrome (RDS).

2. Reduced Risk of Intraventricular Haemorrhage (IVH)

Intraventricular haemorrhage (IVH), or bleeding in the brain, is a major risk for very preterm infants, particularly those born before 30 weeks of gestation. Antenatal steroids have been shown to reduce the incidence of IVH by improving the overall maturity of the brain and other organs.

3. Decreased Incidence of Necrotising Enterocolitis (NEC)

Necrotising enterocolitis (NEC) is a serious intestinal condition that affects preterm infants, especially those born before 32 weeks. By promoting the maturation of the gastrointestinal system, antenatal steroids help reduce the incidence of NEC.

4. Improved Long-Term Development

Babies who receive antenatal steroids are less likely to experience developmental delays, motor impairments, or cognitive issues later in childhood. Research has shown that the earlier the steroids are given, the more significant the long-term health benefits. (American Pregnancy Association, 2023)

Are There Any Risks or Side Effects of Antenatal Steroids?

1. Side Effects for the Mother

For most women, antenatal steroids are well-tolerated. However, some potential side effects include elevated blood sugar levels, particularly in women who already have gestational diabetes or pre-existing diabetes. This can increase the risk of developing gestational diabetes or lead to temporary high blood sugar levels in those who already have it.

There is also a slight increase in the risk of infections due to immune suppression caused by the steroids. However, these risks are generally low and can be managed by healthcare providers who closely monitor the mother’s health during treatment.

2. Potential Risks for the Baby

Some studies have suggested that babies exposed to antenatal steroids may be at a slightly higher risk of developing asthma or wheezing later in childhood. However, the benefits of preventing life-threatening conditions like RDS and IVH generally outweigh these potential risks. It is important to note that the risks of long-term respiratory issues or behavioural problems are minimal in comparison to the significant benefits of antenatal steroids in preventing severe preterm birth complications. (American College of Obstetricians and Gynecologists, 2023)

How Does Antenatal Care Support Preterm Birth Management?

1. Comprehensive Monitoring and Support

Antenatal care is a critical component of managing pregnancies at risk of preterm birth. Regular antenatal checkups, antenatal scans, and antenatal appointments allow healthcare providers to monitor both the mother’s and baby’s health. Early identification of risk factors such as preterm labour or multiple pregnancies allows for timely interventions like antenatal steroids and antenatal support.

Expectant mothers also benefit from education about what to expect during pregnancy, including strategies for prenatal care, antenatal yoga, and techniques to alleviate stress such as prenatal massage.

2. Antenatal Education

Antenatal education is crucial in preparing parents for the potential challenges of preterm birth. Antenatal classes near me provide valuable information on topics such as antenatal fitness, yoga for pregnancy, and how to cope with the emotional and physical demands of preterm labour. Such classes also help parents feel more prepared and supported during this challenging time. (NHS, 2023)

Conclusion

Antenatal steroids are an essential part of pregnancy care for women at risk of preterm birth. By improving lung function, reducing the incidence of preterm complications, and enhancing long-term health outcomes, these steroids play a critical role in supporting healthy outcomes for preterm infants. While there are some risks associated with their use, the benefits far outweigh the potential side effects, especially when the steroids are administered at the appropriate time and dosage.

Expectant parents should work closely with healthcare providers to understand the role of antenatal steroids and the broader aspects of antenatal care, including antenatal checkups, antenatal education, and the support available to manage preterm labour. By staying informed and receiving comprehensive care, parents can ensure the best possible outcome for both mother and baby.