Success rates after transvaginal ultrasound-guided aspiration and fetal puncture in the mare.Original Title Erfolgsraten nach transvaginal-ultraschallgeleiteter Fruchtwasseraspiration und fetaler Punktion bei der Stute.

摘要

Twin pregnancies in the mare usually lead to abortion, stillbirth or the delivery of weak foals. For this reason different reduction methods are applied in studfarm practice. During the mobile phase of the embryo (until D 16) and in bilateral located twins (until D 25) manual crushing of one embryo is the most successful therapy with high survival rates (90-95%) of the remaining embryo. Unilateral and bilateral twins in advanced pregnancies are reduced by transvaginal ultrasound-guided aspiration (TUA), transrectal craniocervical dislocation of one fetus and transabdominal intracardial fetal punction. Different success rates were obtained depending on the location and day of pregnancy. In 2008 and 2009 50 mares between days 25 and 62 of pregnancy were presented for twin reduction via TUA at the clinic. In 46 mares an unicornual and in 4 mares a bicornual location of the twin set was diagnosed. Missing heart beat or the complete absorption of one conceptus revealed a spontaneous reduction of one twin until presentation at the clinic. TUA was performed in 41 mares and 0 to 190 ml of fluid (27.3+or-37.9) were aspirated. In 14 advanced twin pregnancies the aspiration was supported by punction of the embryo. Furthermore in three mares between 47 and 62 days of pregnancy 2-5 ml procaine-penicilline were injected into the fetal cavity, the fetal abdomen or heart. The gynecological examination conducted by the referring veterinarian 5-7 days after TUA revealed one vital conceptus in 29 mares (71%). In three mares two embryos (7%) were observed ultrasonographically, while in 9 mares (21%) both embryos died. 21 of the 29 mares with successful twin reduction at the first pregnancy re-examination were controlled again 3-4 weeks later. 16 mares were still pregnant with one vital conceptus. The day of gestation, fetal puncture or aspiration volume did not influence the pregnancy rates 5-7 days and 3-4 weeks after TUA (p>0.05). TUA is an efficient method for the reduction of advanced twin pregnancies.