Management of twin conceptuses by manual embryonic reduction: comparison of two techniques and three hormone treatments.

The research study involves an examination of how to manage mares carrying twin pregnancies by manually reducing the number of embryos using different techniques and hormonal treatments. This is done in order to understand the subsequent effects on hormone release and pregnancy viability.

Research Methodology

The researchers divided one hundred pregnant mares into four groups, with varying methods of hormone treatment given to each group.

• Group 1 was given a placebo to serve as a control group.
• In Group 2, the mares were given a single dose of progesterone.
• Group 3 received multiple doses of progesterone at 6-day intervals until gestation day 42.
• Group 4 received a single dose of both flunixin meglumine, a non-steroidal anti-inflammatory drug, and progesterone.

Subgroups were then created based on the age of the embryos, with subgroup A having younger embryos and subgroup B older ones. The technique performed in these subgroups involved the rupture of the embryonic vesicle, either after it was moved to the tip of the uterine horn or in situ (in its original place).

Research Findings

The process of rupturing the embryonic vesicle generally caused a release of a hormone called prostaglandin (PG) F2 alpha for a duration of up to 90 minutes. The amount of this hormone released was directly related to the pressure needed to cause the vesicle rupture.

Attempting to rupture the vesicle but not actually doing so (sham vesicle rupture) also caused a brief release of PGF2 alpha. Despite this, all mares who had a sham vesicle rupture remained pregnant until gestation day 42.

The research findings also showed that the treatment of flunixin meglumine reduced the amount of PGF2 alpha release after the embryonic vesicle rupture. This was observed irrespective of the technique used to rupture the vesicle.

The study does not continue beyond this point in the abstract, but the findings suggest that flunixin meglumine might play a role in maintaining pregnancy after manual embryonic reduction by inhibiting the release of PGF2 alpha.