comparison of the effect of betamethasone versus dexamethasone on the amniotic fluid index in the women at risk of preterm labor

background: the aim of this study was to compare the biophysical profile parameters (bpp), especially amniotic fluid index (afi), before and after administration of corticosteroids (dexamethasone and betamethasone) and these two groups with each other. materials and methods: this double-blind clinical trial study was done on 70 patients for 28–34 weeks women having at least one preterm labor in their previous pregnancy has been submitted in al zahra and shahid beheshti clinic in 2012–2013. 70 women were randomly allocated in two groups. the first group were received 8 mg each 12 h for 4 doses dexamethasone when the patient at risk of preterm labor admitted in clinic or hospitalized and the second group were received 12 mg betamethasone each 24 h similarly. nonstress test (nst) and bpp and sonography afi were done in all cases, and then nst was done in the before and 3 days after intervention. data were analyzed by spss software version 20 using t -test, chi-square, and fisher’s test. results: there was no significant difference between the range of afi before and after the drug intervention ( p > 0.05). two groups had no significant difference in afi before and after administration of corticosteroids. no significant difference was seen in nst acceleration tests between the two groups before and after corticosteroids administration. conclusion: biophysical profile had a significant difference in dexamethasone group respect to that of betamethasone group. furthermore, the biophysical profile had a significant difference before and after the administration of corticosteroids in two groups. it is noted that afi had no role in this matter.