Effect of uterine torsion intrapartum on concentrations of placental estrogens and progesterone in cattle.

Objective: The current study investigates how uterine torsion influences placental oestrogens and progesterone blood concentrations in intrapartum cows. Our research tests the hypothesis that intrapartum uterine torsion impairs the ability of the placenta to synthesize steroids and may also suppress the release of synthesized steroids into the maternal circulation.

Methods: The study included a total number of 37 intrapartum dairy cows of various breeds and ages. These animals were transported to our clinic by their owners. Furthermore, general and obstetrical examinations of all these animals were performed in our clinic. The uterine torsion (UT) group consisted of 20 animals. The presence of UT was verified during clinical general examinations by vaginal and transrectal examination. The comparison (C) group included 17 animals whose birth was undisturbed or could be terminated with moderate obstetrical assistance. The clinical examination of group C animals showed no problems with their general health and genital organs. Blood samples were collected immediately after the initial obstetrical examination from 37 cows for radioimmunological measurement of estradiol-17β (E2), free total estrogen (FTE), conjugated total estrogen (CTE), and progesterone (P4).

Results: In terms of P4, there was no statistical difference between the two groups. For all estrogen parameters, however, concentrations were significantly lower in the UT group than in the C group. In the correlation analysis, there was a significant correlation between the P4 and the FTE in the C group. Furthermore, the positive correlation between all estrogen parameters in the UT group was significant. In group C, significant positive correlations were found apart from the correlation between E2 and CTE.

Conclusions: The results are consistent with the hypothesis and suggest that in UT animals processes dependent on estrogens or other placental hormones may be impaired during the peri- or postpartum period.