P1130039

Ejcperiences with transvaginal punctures of concep-tuses in the horse are stiłl limitcd. In the punctures per-formed thus far one could usually observe a change in the typical features of the embryo or fetus immediately following penetration of the vesicle by the puncture needle (Fig. 1.81 and 1.82). Within the vesicle echoes reminiscent of floating parts of membranes became evi-dent. These were assuraed to have been freed placental membranes. Immediately after the puncture the embryo changed its position, coming to rest on the floor of the veside.

To datę six punctures on singleton pregnancies have been performed between Days 19 and 75 with the aim of aspirating smali quantities of placental fluid. In 4 pregnancies which were performed between Days 19 and 50 the conceptus died after the puncture. One eon* ceptus which had been punctured on Day 54, and front which 7 ml allantoic fluid had been collected, continued to develop (Fig. 1.83). This pregnancy was purposefully interrupted on Day 75 by the collection of a large vol-ume of fetal fluid.

Only one conceptus was punctured in each of two twin pregnancies on Days 29 and 44 of gestation, re-spectively. The remaining member of the twin pregnancy was intended to persist and develop as a singleton pregnancy. In both cases, however, both conceptuses died. In all cases the death of the conceptus was ap-parent within days of the puncture. Usually, a heart beat could not be detected by ultrasonography on the day following the puncture.