Objective:

To evaluate the effects of antenatal betamethasone administration on fetal biophysical activities, Doppler flow indices of the fetal and uterine arteries and neonatal apgar scores.

Design:

Prospective controlled study

Setting:

Etlik Zübeyde Hanım Women’s Hospital

Patients:

Forty women at risk of preterm delivery between 26-34 weeks gestation were taken as study group. 40 pregnant women with the same demographic characteristics and the same gestational age were taken as controls.

Interventions:

Patients in study group received two consecutive doses of intramuscular betamethasone 24 hours apart. Fetal biophysical profile and Doppler examinations were performed prior to (0 h), 48 h and 96 h after administration of the first dose. We used Friedmans test and one way analysis of variance of repeated measures All patients were followed until delivery and evaluated for apgar scores

Main outcome measures:

Effects of antenatal betamethasone administration on fetal biophysical activities and Doppler flow indices.

Results:

Study and control group were similar in respect to demographic charecteristics and basal doppler values. Biophysical profile were normal before betamethasone in all patients. There was a statistically significant difference in the frequency of absence of body movements in 14(35%) patients at 48 h(P<0.05), absence of breathing movements in 31(77.5%) patients 48 h(P<0.05) and non-reassuring fetal heart rate tracings in 14(35%) patients at 48 h(P<0.05). All the parameters returned to normal at 96 h. None of the Doppler indices was found to be affected by the steroid administration. There was no difference between two groups with respect to the type of delivery Apgar scores

Conclusions:

Antenatal betamethasone administration can cause a transient suppression of fetal biophysical profile parameters, resulting in decreased biophysical profile scores but doppler indices were found to be unaffected. Awareness of this effect might prevent unnecessary iatrogenic delivery of preterm fetuses.

Keywords: betamethasone, preterm labour, biophysical profile, doppler velocimetry