Midluteal phase Doppler assessment of uterine artery blood flow in nonpregnant women having a history of recurrent spontaneous abortions: correlation to different etiologies

Objective: To compare the impedance to uterine artery blood flow, during the midluteal phase, in women with recurrent spontaneous abortion (RSA) as compared to normal fertile controls. Design: A prospective study involving women with a history of RSA and fertile controls. Setting: University of Rome "Tor Vergata." Patient(s): Two hundred thirty women with RSA and 50 fertile controls referred for routine examination. Intervention(s): Transvaginal Doppler examination of uterine arteries during the midluteal phase of untreated cycles. Main Outcome Measure(s): The mean pulsatility index (PI) of uterine arteries. Result(s): Uterine arteries PI values in RSA patients (2.42 +/- 0.79) were significantly higher with respect to those found in the control group (2.08 +/- 0.47). When patients were grouped according to the different RSA causes, the highest PI values were found among patients with uterine abnormalities (2.82 +/- 1.0), antiphospholipid antibodies syndrome (2.70 +/- 1.1), and unexplained RSA (2.60 +/- 0.7). These values were significantly higher with respect to that found in the control group. No differences were observed in PI values between fertile patients and those with RSA due to thyroid abnormalities (2.10 +/- 0.55), inherited thrombophilia (2.03 +/- 0.45), autoimmune pathology (2.34 +/- 1.18), and genetic anomalies (2.47 +/- 0.54). Similar results were observed when patients were grouped according to primary and secondary RSA. Conclusion(s): Increased resistance to uterine blood flow may be an important contributing factor to some causes of RSA and may represent an independent indication of the risk of pregnancy loss.