垂体降调节后促性腺激素启动时机的选择

体外受精-胚胎移植(IVF-ET)治疗过程中,传统的降调节方案已演化为各种各样的个体化促性腺激素释放激素激动剂(GnRH-a)降调节。其目的是垂体被抑制得恰到好处,具有合适的LH水平和E2水平,同时窦卵泡的大小均匀,此时启动促性腺激素(Gn),卵泡对外源性Gn敏感性好,错开了卵泡无反应平台期的刺激时间和剂量,降低Gn用药剂量及用药时间,从而减轻患者的经济负担和精神压力,可以获得良好的临床结局。常用的降调节标准是Gn启动前血清E2≤50pg/m1(183pmol/L),LH5U/L,卵泡直径5~10mm及子宫内膜厚度≤5mm。

Selection of gonadotropin start timing after pituitary down regulation

During IVF-ET cycles,individual pituitary down-regulation protocol with GnRH agonist has been developed on the basis of the traditional down-regulation protocol.The aim of down-regulation is to achieve a proper level of LH and E2,while the size of antral follicles is uniform.The follicles are sensitive to the gonadotropin(Gn) at this time,so the doses and duration of Gn administration are decreased.As a result,a better clinical outcome can be reached and the economic burden of patients also can be reduced.There are several indicators for Gn start timing in the down-regulation protocols:serum E2 level≤183 pmol/L,LH＜5 U/L,the diameter of follicles range from 5 mm to 10 mm and the thickness of endometrium ≤5 mm.