How to Increase Embryo Recovery Rates and Transfer Success

摘要

Changes in breed registry rules have resulted in an increase in the number of embryo transfers performed in the United States in the past 2 yr. The basic technique used by practitioners to recover embryos from donor mares has remained the same for many years. The standard method of embryo collection in the mare is a nonsurgical transcervical uterine lavage. A sterile catheter with an inflatable cuff is inserted through the cervix, and the cuff is inflated with 60-80 ml of air. The uterus is lavaged three times with 1-1.5 1 of prewarmed (30-35°C) embryo flush medium each time. The flush medium is allowed to flow back out the catheter by gravity flow and is passed through an embryo filter. Recovery of the flush medium may be aided by massage of the uterus per rectum, and occasionally, administration of oxytocin (i.e., 20 IU, IV). Recovery of the uterine lavage fluid is monitored by collection of the effluent fluid in graduated cylinders. Contents of the filter are poured into a search dish and examined for the presence of an embryo.