Assessment of sub-endometrial blood flow parameters following dydrogesterone and micronized vaginal progesterone administration in women with idiopathic recurrent miscarriage: a pilot study.

AIM To evaluate differences in uteroplacental blood flow and pregnancy outcome in women with idiopathic recurrent spontaneous miscarriage (IRSM) following administration of micronized vaginal progesterone and oral dydrogesterone. METHODS One hundred and thirty-three women (aged 23-40 years) who had had early miscarriages and spontaneous conception participated. Oral dydrogesterone (group A, n = 51) and micronized vaginal progesterone (group B, n = 50) were administrated for luteal support and compared. Pregnant women without history of recurrent miscarriage served as controls (group C, n = 32). The outcome measures consisted of endometrial blood flow parameters by Doppler indices and ongoing pregnancy rate. RESULTS Before progesterone supplementation, resistivity index (RI) and pulsatility index (PI) were found to be significantly higher in groups A and B as compared to controls. Although statistically not significant, end diastolic velocity (EDV) and systolic/diastolic (S/D) ratio was found to be superior in controls than IRSM women. Peak systolic velocity (PSV) was comparable between IRSM and non-IRSM groups. Following progesterone supplementation, groups A and B showed a highly significant reduction in RI, PI and an increase in EDV. A relative increase in the value of PSV was observed in group A as compared to group B. There was remarkable difference in S/D in both groups. Although not statistically significant, group C showed reduction in RI, PI, PSV, EDV and S/D ratio. Pregnancy salvage rates were higher in group A (92.0%) as compared to group B (82.3%). CONCLUSION Progesterone supplementation appears to lower vascular resistance in women with IRSM. Oral dydrogesterone appears to be equally effective in improving endometrial blood flow as compared with micronized progesterone.