Direct intramuscular fetal or maternal antenatal corticosteroid therapy: short-time effects on fetal behavior and oxygenation: a comparative study.

OBJECTIVE: To compare the effects of antenatal administration of corticosteroids used in two different regimens, on fetal biophysical profile (BPP), baseline fetal heart rate (BFHR), nonstress test (NST) and perinatal outcomes.

STUDY DESIGN: We evaluated the effects of single direct intramuscular (i.m.) fetal dose of dexamethasone (4 mg/kg), or four doses of 6 mg dexamethasone given to the mother 12 hours apart on the parameters of fetal BPP 0-4 hours before and after antenatal contraction stress (ACST). We evaluated two groups of 41 fetuses in the 31st gestation week at risk of fetal hypoxia at the Department of Gynecology/Obstetrics, Clinical Center of Serbia in 2013.

RESULTS: In fetal ACST group, we found significantly different changes in fetal breathing movement before (D0-f) and after therapy (D1-f), p  =  0.019 (-11.75; -1.12), 95% confidence interval (CI), as well as in the maternal ACST group, p  =  0.001; (-11.75; -1.12), 95% CI. We found significant difference between BPP 0-m and BPP1-m in the maternal group, p =  0.000. Neonatal asphyxia occurred more often with the increased frequency of fetal breath movements after both ACST (p  =  0.04 versus p  =  0.07).

CONCLUSION: Fetal ACST results in increased fetal breathing movements. Maternal ACST can result in changes to BPP. The increase in fetal breathing movements determinates neonatal asphyxia regardless of the ACST.