Clinical efficacy of spermatid conception: analysis using a new spermatid classification scheme

Fertilization and pregnancy outcomes of 50 round spermatid injection (ROSI) and 20 elongated spermatid injection (ELSI) treatment cycles are related to various characteristics of the cycles, with particular reference to spermatid developmental stage as assessed by using a classification scheme adapted to this purpose. Although this classification includes eight stages, a complete block was mostly detected at the earliest stage (Sal) or at the latest stages (Sdl and Sd2). Thus, spermiogenesis was blocked at Sal stage in 50 cases (71%), at Sdl stage in eight cases (11%) and at Sd2 stage in 10 cases (14%). Only in two cases (3%) was spermiogenesis blocked at an intermediate stage (Sb2). Globally, fertilization rates were higher for ELSI than for ROSI. No pregnancy was achieved in the ROSI cycles, whereas nine pregnancies resulted from the ELSI cycles. Two of them (both with Sd2 spermatids) ended in a first trimester spontaneous abortion. Of the seven ongoing pregnancies, five are singleton (two with Sdl spermatids, two with Sd2 spermatids, and one after a mixed transfer after injection of Sa2 and Sdl spermatids) and two are twin (one with Sdl and the other with Sd2 spermatids). No pregnancy was achieved in the two cycles with Sb2 spermatids. One of the two twin pregnancies has already resulted in the birth of two healthy children.