Foetal and maternal plasma concentrations of 13, 14-dihydro-15-oxo-prostaglandin F in the mare during late pregnancy and at parturition.

This research observes how the levels of 13, 14-dihydro-15-oxo-prostaglandin F(PGFM), a certain stable metabolite, vary in pregnant horses, particularly near birth or during operations. The study reveals that the concentration of PGFM increases towards the end of pregnancy, is affected by operations and prior fasting, and is highly correlated to the birth of live offspring.

Objective and Methodology

• The researchers aimed to measure the concentrations of prostaglandin F metabolite PGFM in the plasma of pregnant mares and foetuses during the last months of gestation and during parturition (childbirth).
• To achieve this, blood samples were taken from catheterized (fitted with a catheter for administering or removing fluids) and non-catheterized pregnant mares and their foetuses.

Findings

• The study found that the plasma concentration of PGFM increased gradually as term neared in all groups of examined animals. This means that as the horses got closer to giving birth, the concentration of this specific metabolite in their blood increased.
• During the operation for inserting catheters, both maternal and foetal concentrations of PGFM were high, but these levels reduced to basal (minimal) levels 24 to 48 hours after the operation. This indicated that the operational stress or trauma was temporarily increasing PGFM levels.
• Preoperative fasting, or not eating 24 hours prior to operation, also led to an increase in PGFM concentration in the maternal plasma, suggesting possible stress or metabolic responses.

Parturition or Birth Association

• The researchers found that PGFM concentrations were higher during normal parturition (birth) in thoroughbred horses, particularly during the second stage of labour. PGFM levels also rose sharply after the use of oxytocin, a hormone that stimulates contractions during labour.
• In the case of catheterized animals, the birth of live foetuses was associated with an increase in the concentration of PGFM in both foetal and maternal plasma during the last 2 hours before delivery. This might indicate this metabolite’s involvement in final stages of parturition.
• Abnormal events like premature delivery or abortion showed less consistent changes in PGFM concentration, indicating that PGFM level fluctuations might be more strongly linked to normal birth processes.

Conclusion

• The research concluding the increasing concentration of PGFM in maternal and foetal plasma towards term and during birth processes indicates that this metabolite potentially plays a significant role during the gestation and parturition in horses.
• The finding can be helpful in veterinary medicine for managing horse pregnancy and childbirth complications by monitoring and potentially manipulating PGFM levels.