The use of late preterm betamethasone (antenatal corticosteroids given between 34 and 36 weeks of gestation) is a critical intervention. Clinicians prescribe this medication to reduce serious respiratory complications in newborns. However, long-term safety concerns persist for the exposed children. Investigators from the Antenatal Late Preterm Steroids (ALPS) trial recently published follow-up data. They specifically evaluated childhood pulmonary outcomes. We will review the key findings concerning respiratory health at school age.
Long-Term Safety Profile of Late Preterm Betamethasone
The follow-up study was a prospective evaluation of children aged six years and older. The initial ALPS trial participants were randomized to receive betamethasone or a placebo. Researchers defined a composite primary outcome of childhood respiratory impairment. This outcome included three main components: abnormal spirometry, physician-diagnosed asthma plus daily medication, or daily asthma medication use in the preceding year. Importantly, researchers found no statistically significant difference in this primary composite outcome between the betamethasone group (35.3%) and the placebo group (35.8%). The adjusted relative risk was 1.02. Therefore, late preterm betamethasone did not increase the overall risk of major respiratory impairment.
Specific Respiratory Symptoms and Term Comparisons
The study did uncover differences in certain secondary outcomes. For instance, the ever-noting of wheezing or whistling in the chest was actually less common in the betamethasone group compared to the placebo group (40.7% versus 45.5%). This difference was statistically significant. Moreover, the investigators included a term reference cohort for context. They found that ALPS children, regardless of corticosteroid exposure, had a higher rate of wheezing with exercise compared to the term control group. The betamethasone group’s rate was 7.2%, while the term control rate was 4.4%. This suggests that being born late preterm itself might pose a greater risk for exercise-related wheezing. Furthermore, previous research has already shown that late preterm infants face increased risks for neonatal respiratory issues and other adverse outcomes compared to full-term infants.
Broader Context: Neurodevelopmental Follow-up
Because clinicians often worry about the overall safety profile, it is helpful to consider other follow-up data. Previous studies have consistently shown that the use of antenatal corticosteroids in the late preterm period increases the risk of neonatal hypoglycemia. However, persistent hypoglycemia can potentially cause adverse neurodevelopmental outcomes. A separate ALPS follow-up specifically evaluated neurodevelopmental outcomes in these children at age six. That analysis demonstrated no difference in the risk of low general cognitive ability between the betamethasone and placebo groups. Consequently, these two key follow-up studies provide reassuring evidence on the long-term safety of this practice for both lung function and neurodevelopment.
Frequently Asked Questions
Q1: Does late preterm betamethasone increase the risk of asthma in childhood?
No, the ALPS follow-up study found no difference in the primary composite outcome of childhood respiratory impairment, which included physician-diagnosed asthma and daily medication use.
Q2: What was the main positive effect of antenatal betamethasone on respiratory health in older children?
Antenatal betamethasone exposure was associated with a statistically lower rate of ever-noting wheezing or whistling in the chest in children aged six years or older compared to placebo.
Q3: How did late preterm children compare to full-term children regarding respiratory symptoms?
Regardless of whether they received betamethasone or placebo, children born late preterm (ALPS participants) had a higher rate of wheezing with exercise in the past year compared to a full-term reference cohort.
References
- Gyamfi-Bannerman C et al. Childhood Pulmonary Outcomes After Late Preterm Antenatal Corticosteroids. Obstet Gynecol. 2026 Jan 22. doi: 10.1097/AOG.0000000000006162. PMID: 41570323.
- Gyamfi-Bannerman C et al. Neurodevelopmental Outcomes After Late Preterm Antenatal Corticosteroids: The ALPS Follow-Up Study. JAMA. 2024 May 21.
- ClinicalTrials.gov. Antenatal Late Preterm Steroids (ALPS): A Randomized Placebo-Controlled Trial (NCT01222247).