Short-Term Effects of Betamethasone Administration on Fetal Heart Rate Patterns in Preterm Contraction

Area of Science:

• Obstetrics and Gynecology
• Neonatal Medicine
• Pharmacology

Background:

• Preterm labor is a significant global cause of infant illness and death.
• Antenatal corticosteroid therapy, specifically betamethasone, is a standard treatment to enhance neonatal outcomes.

Purpose of the Study:

• To assess the immediate impact of maternal betamethasone on fetal heart rate variability (HRV) in preterm labor using nonstress test (NST) data.

Main Methods:

• A prospective study involved 62 women with preterm contractions (28-34 weeks gestation).
• Participants received two 12 mg intramuscular doses of betamethasone, 12 hours apart.
• Cardiotocography (CTG) recordings were analyzed for baseline FHR, beat-to-beat variability, accelerations, and decelerations at multiple time points post-administration.

Main Results:

• Betamethasone administration led to a temporary decrease in baseline FHR and beat-to-beat variability, peaking at 24-36 hours.
• Fetal heart rate parameters normalized by 72 hours post-treatment (P < 0.0001).
• While accelerations decreased initially, decelerations were consistently absent.

Conclusions:

• Maternal betamethasone causes transient, reversible changes in fetal heart rate patterns.
• These alterations in fetal heart rate variability and accelerations were not associated with adverse perinatal outcomes.