The temporal link between prenatal steroid therapy and labor.

Area of Science:

• Perinatal Medicine
• Neonatalogy
• Obstetrics

Background:

• Preterm birth remains a significant challenge in perinatal medicine.
• Antenatal glucocorticoid therapy is recommended for threatened preterm labor between 24-34 weeks gestation.
• Optimal benefits are observed when labor occurs 24 hours to 7 days post-steroid administration.

Purpose of the Study:

• To analyze the time interval between antenatal glucocorticoid administration and labor in patients with threatened preterm labor.
• To evaluate the adherence to the recommended 7-day window for labor onset after steroid therapy.

Main Methods:

• Retrospective analysis of 459 deliveries between 24-34 weeks gestation who received betamethasone or dexamethasone.
• Patients categorized by indication for glucocorticoid therapy: threatened preterm labor, premature rupture of membranes, iatrogenic prematurity, cervical incompetence.
• Neonates grouped by birth within 7 days (n=127) or more than 7 days (n=403) after therapy; statistical analysis using Mann-Whitney U and chi-squared tests.

Main Results:

• Only 23.96% (127 neonates) were born within the recommended 7-day window after glucocorticoid therapy.
• The average delay between steroid administration and labor was 33 days, with a maximum of 116 days.
• Iatrogenic causes were the most common indication in the early (<7 days) birth group, while threatened preterm labor signs predominated in the later (>7 days) group.

Conclusions:

• The observed percentage of births within the recommended 7-day period following antenatal steroid therapy was lower than anticipated.
• Current methods for qualifying patients for prenatal steroid therapy require re-evaluation, particularly when signs of preterm labor are present.
• This suggests potential for optimizing the timing and selection of patients for glucocorticoid treatment to improve perinatal outcomes.