Cervical transposition test using Hegar dilator at oestrus as a tool to select ewes for transcervical embryo collection

Abstract

This study evaluated the cervical transposition method as a tool to select ewes for embryo collection by transcervical route. Adult Santa Inês ewes (n = 50) received Day 0 protocol for superovulation treatments. The cervix transposition test was performed both at oestrus and at the embryo collection time. The latter was preceded by hormonal cervical dilation. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 85.7%, 66.6%, 85.7%, 66.6% and 80.0%, respectively. The kappa index yielded a moderate score (κ = 0.52). In conclusion, the high sensitivity and accuracy indicate that the cervical transposition test is a screening option to select ewes for embryo collection by transcervical route.

Comparison of the intravenous and intravaginal route of oxytocin administration for cervical dilation protocol and non‐surgical embryo recovery in oestrous‐induced Santa Inês ewes

“…The factors that mostly limit cervical penetration in sheep are the number and distribution of cervical folds and small inner diameter of the cervical lumen (Kaabi et al, ). Multiple attempts have been made to improve NSER in ewes, including the development and refinement of techniques for transcervical penetration and embryo flushing, screening and selection of donor ewes (Santos et al, ), and advances in understanding the mechanisms of cervical ripening that paved the way to various hormonal protocols for cervical dilation (Candappa & Bartlewski, ; Fonseca, Zambrini, Guimarães, Silva, Oliveira, Bartlewski, et al ).…”

Use of oxytocin to attain cervical dilation for transcervical embryo transfer in sheep

“…Ewes were then restrained on a table (1.2 m tall) using a rounded, rubberized wooden device that allowed the perineum to be exposed (Figure 2a). Cervix visualization, traction and restraint were performed as previously described by Santos et al (2019). Briefly, after the cervix was located with a speculum and a light source, the cervical os was clipped with Allis forceps and exteriorized by caudal traction using two Pozzi forceps inserted on each side of the cervical os in the fornix region.…”

Ultrasonographic cervical evaluation: A tool to select ewes for non‐surgical embryo recovery

“…An attempt at cervical transposing performed between 10 and 12 hr after the oestrus onset (natural, induced or synchronized) with a Hegar dilator allows the creation of a cervical map, recording the geographic‐anatomical arrangement of the rings (Fonseca, 2017; Fonseca, et al., 2019). The records of cervical transposing allow for individuals to be ranked by the degree of ease, enabling donor selection and success in the NSER (Fonseca, 2017; Fonseca, et al., 2019; Santos et al., 2019). This evaluation has an accuracy of about 80% due to false positives and negatives (Fonseca et al., 2019a; Santos et al., 2019).…”

“…However, the feasibility of cervical access and manipulation (i.e. immobilization, retraction and penetrability) should be tested in individual donor ewes before any embryo collection attempt, aiming better effectiveness in the application of NSER (Fonseca, 2017;Fonseca et al, 2019aFonseca et al, , 2019bSantos et al, 2019).…”

“…The records of cervical transposing allow for individuals to be ranked by the degree of ease, enabling donor selection and success in the NSER (Fonseca, 2017;Fonseca, et al, 2019;Santos et al, 2019). This evaluation has an accuracy of about 80% due to false positives and negatives (Fonseca et al, 2019a;Santos et al, 2019).…”