Relación entre duración y dificultad de la transferencia de embriones con la tasa de preñez en vaconas y la capacidad del flunixin meglumine (FM) aplicado IV o IM para modificarla

Abstract

Two key points exist in superovulation and embryo transfer (SOET): the recovery of the embryos in the donor and the gestation of the embryos in the recipient. Embryo transfer at such, presents some difficulties that are the cause of gestation loss. Both, the maneuver duration (objective measurement) and the difficulty manifested by the operator (subjective measure) have been mentioned by several authors but rarely studied together and connected to pregnancy. It is known that such difficulties cause PGF2α release and this produces negative effects on both, the embryo and the corpus luteum. From the first minutes after the start of the maneuver, elevated levels of this hormone in the blood are observed. The use of Flunixin Meglumine (FM) antiprostaglandins applied at the time of embryo transfer (ET) has been attempted with varying results. The intramuscular injection used by all authors was not always connected to the difficulty of the transfer and both facts may explain the divergence of the information. The aims of this study were: 1) to determine the relationship between the difficulties observed in embryo transfer and the pregnancy rate; and 2) to evaluate whether intramuscular (IM) or intravenous (IV) can modify this relationship. 110 recipients were used, the duration of the transfer and the difficulty manifested by the operator were measured. These recipients were divided in three groups: control (no treatment); 2,2 mg / kg FM IM and 2,2 mg / kg FM IV. The pregnancy rate was determined between 30-40 days post ET and a reconfirmation was performed at 60-90 days post ET. The application of FM IV post TE showed a gestation rate significantly higher at 30-40 days (75%, p <0,001) compared to the control group (45%) and IM group (33,3%). It is concluded that the FM IV application is effective in improving the gestation rate in embryo recipients when the transfer lasts less than 45,5 seconds.