COMPARATIVE ASSESSMENT OF FETAL CARDIOTOCOGRAPHIC CHANGES FOLLOWING ANTENATAL DEXAMETHASONE AND BETAMETHASONE ADMINISTRATION

Abstract

Objective: To compare the effects of antenatal dexamethasone and betamethasone on antepartum cardiotocographic (CTG) parameters, particularly fetal heart rate accelerations and baseline variability, among pregnant women at risk of preterm delivery. Study Design: Prospective comparative study. Place and Duration of Study: Department of Obstetrics and Gynaecology in Tertiary Care Hospitals of Pakistan, over a proposed six-month study period from November 2025 to April 2026. Methodology: A sample of 220 pregnant women at risk of preterm delivery was divided equally into two groups. Group A received dexamethasone 6 mg intramuscularly every 12 hours for four doses, while Group B received betamethasone 12 mg intramuscularly every 24 hours for two doses. CTG parameters were assessed before treatment and at 24, 48, and 96 hours. Primary outcomes were fetal heart rate accelerations and baseline variability. Secondary outcomes included baseline fetal heart rate, CTG classification, and recovery of CTG parameters. Continuous and categorical variables were compared using appropriate statistical tests. Results: At 24 hours, mean fetal heart rate accelerations decreased from 5.2 ± 1.7 to 3.9 ± 1.6 in the dexamethasone group and from 5.1 ± 1.6 to 3.5 ± 1.5 in the betamethasone group (p=0.048). Baseline variability decreased from 8.7 ± 2.1 to 7.1 ± 2.0 bpm with dexamethasone and from 8.6 ± 2.0 to 6.4 ± 1.9 bpm with betamethasone (p=0.012). Both parameters progressively recovered, with no significant between-group differences at 96 hours. Pathological CTG patterns were uncommon. Conclusion: In this study, both antenatal corticosteroids were associated with transient CTG changes, with somewhat greater reductions in accelerations and variability after betamethasone. These changes largely resolved by 96 hours. Actual clinical conclusions require analysis of a verified patient dataset.