Adjuvant L-arginine treatment for in-vitro fertilization in poor responderpatients

The objective of the present study was prospectively and randomly to evalua te the role of L-arginine in improving uterine and follicular Doppler flow and in improving ovarian response to gonadotrophin in poor responder women. A total of 34 patients undergoing assisted reproduction was divided in two groups according to different ovarian stimulation protocols: (1) flare-up gonadotrophin-releasing hormone analogue (GnRHa) plus elevated pure follicl e stimulating hormone (pFSH) (n = 17); and (11) flare-up GnRHa plus elevate d pFSH plus oral L-arginine (n = 17), During the ovarian stimulation regime n, the patients were submitted to hormonal (oestradiol and growth hormone), ultrasonographic (follicular number and diameter, endometrial thickness) a nd Doppler (uterine and perifollicular arteries) evaluations. Furthermore, the plasma and follicular fluid concentrations of arginine, citrulline, nit rite/nitrate (NO2-/NO3-), and insulin-like growth factor-1 (IGF-1) were ass ayed. All 34 patients completed the study. In the L-arginine treated group a lower cancellation rate, an increased number of oocytes collected, and em bryos transferred were observed, In the same group, increased plasma and fo llicular fluid concentrations of arginine, citrulline, NO2-/NO3-, and IGF-1 was observed, Significant Doppler flow improvement was obtained in the L-a rginine supplemented group. Three pregnancies were registered in these pati ents. No pregnancies were observed in the other group. It was concluded tha t oral L-arginine supplementation in poor responder patients may improve ov arian response, endometrial receptivity and pregnancy rate.