Factors affecting pregnancy rates and early embryonic death after equine embryo transfer

摘要: In the present study, 638 embryo transfers conducted over 3 yr were retrospectively examined to determine which factors (recipient, and transfer) significantly influenced pregnancy loss rates how could be improved. On Day 7 or 8 after ovulation, embryos (fresh cooled/transported) transferred by surgical nonsurgical techniques into recipients ovulating from 5 9 d before transfer. At 12 50 of gestation (Day 0 = day ovulation), 65.7% (419 638) 55.5% (354 638). Pregnancy on higher for that had excellent good uterine tone graded as "acceptable" during a pretransfer examination, usually performed versus fair poor "marginally acceptable." Embryonic affected morphology grade, diameter stage development. The incidence early embryonic death was 15.5% (65 419) Days 50. Embryo in used vs 6 ovulation. Embryos with minor morphological changes (Grade 2) resulted more (P<0.05) than no abnormalities 1). Between 50, highest occurred interval 17 25 gestation. vesicles imaged ultrasound first exam (5 fewer deaths not until subsequent exams. predictive potential an result viable pregnancy. Delayed development upon collection donor delayed vesicle within recipient's uterus associated failure. Recipient selection (age, quality 5) rates.