Gender determination in equine fetuses between days 50 and 90 of pregnancy

Abstract

For fetal gender determination, 169 thoroughbred mares were examined with ultrasound between Days 50 and 70 of pregnancy. Sex differentiation was based on the position of the genital tubercle (GT), which during this time window can be located in male fetuses close to the umbilicus and in female fetuses close to the tail. Evaluation of a total of 195 examinations revealed that video-recordings almost doubled the chance to correctly diagnose gender, which was confirmed at birth. Overall, a diagnosis could be achieved in 99 mares only (50.7%), which was correct in 85%. In mares examined between Days 60 and 70, a diagnosis was possible in 46 cases (72%), which was correct in 87% (40 cases). Male fetuses were diagnosed easier due to the larger genital tubercle.