Ultrasonographic assessment of in utero fetal presentation, position and posture can be essential: case report

The objectives of this clinical case report were to highlight the value of late transrectal ultrasound examination for assessing fetal presentation, position and posture and to describe the management of a case of malposture associated with musculoskeletal and cerebellar abnormalities, including its in utero ultrasound diagnosis and outcome. A 7-year-old Gypsy Vanner mare, 339 days pregnant, was diagnosed with the presence of a bony fetal structure cranial to the cervix, without palpable head or limbs and minimal fetal movement. Transrectal ultrasound examination was instrumental in diagnosing a cranial presentation along with an abnormal posture (right-sided deviation of the fetus's neck, and a head in flexion). Transabdominal ultrasound examination confirmed the cranial presentation, with the fetus positioned high in the mare's pelvis. As soon as the parturition started at 349 days gestation, the mare underwent a cesarean section. The foal was stillborn, covered with meconium. Pathological examination revealed cerebellar lesions (hypoplastic granular cell layer, reduced number of Purkinje cells, and gliosis) as well as musculoskeletal abnormalities including arthrogryposis, scoliosis, angulation of the occipital condyles and sternum deformity. Genetic analysis showed underlying genetic abnormalities that may have contributed to abnormal fetal development and potentially to the observed malposition/posture. The mare recovered uneventfully from the cesarean section and went home seven days postoperatively. This case underscores the diagnostic value of a pre-foaling ultrasound examination to assess fetal presentation, position and posture, which was critical in preparing for a planned cesarean section and ultimately saving the mare.