Abstract This study was conducted to evaluate and compare the diagnostic efficacy of transrectal ultrasonography (TRU) and serum progesterone (P4) assay for early pregnancy detection in local Iraqi ewes. A total of fifteen multiparous non-pregnant ewes (2–4 years old) were synchronized using intravaginal sponges containing Medroxyprogesterone Acetate (MPA) and 500 IU equine chorionic gonadotropin (eCG), followed by natural mating. Blood samples were collected on days 0, 14, 21, and 30 post-inseminations (PI) for hormonal analysis. TRU was employed concurrently on the same days to visualize pregnancy indicators. The results revealed that TRU had limited accuracy during the early stages (day 14–21 PI), with accuracy rates ranging from 26.7–60%, while improving substantially by day 30 PI (accuracy: 100%). In contrast, serum P4 levels demonstrated a statistically significant elevation in pregnant ewes compared to non-pregnant and control groups from day 14 onward, achieving full diagnostic accuracy by day 21 PI. Receiver operating characteristic (ROC) analysis confirmed the high predictive value of P4, especially on days 21 and 30 (AUC = 1.000). In conclusion, P4 assay serves as a more sensitive and reliable diagnostic tool for early pregnancy (days 14–21), whereas ultrasonography offers superior accuracy at later gestational stages (day 30 onward), thus supporting a complementary role for both techniques in reproductive management.
Abood et al. (2025) studied this question.