Correlations of Serum Progesterone Concentration with Uterine and Fetal Weights at Weeks 7 and 15 of Pregnancy in Javanese Thin-Tail Ewes

Seventeen pregnant ewes (8 superovulated and 9 non-superovulated) were used to study correlations of maternal serum progesterone concentrations with uterine and fatal weights at weeks 7 and 15 of pregnancy. Statistical analyses indicated that uterine growth during the first 7 weeks of pregnancy highly associated with maternal serum progesterone concentration (r=0.87 and 0.85, with wet and dry uterine weights, respectively). Ewes with higher maternal serum progesterone concentrations had higher total and average fetal weights at week 7 of pregnancy (r=0.89 and 0.86, respectively). At week 7 of pregnancy, wet and dry uterine weights highly correlated (p<0.01) with total and average fatal weights (r=0.99 and 0.80, 0.98 and 0.75, respectively). Maternal serum progesterone concentrations, however, did not correlate (p>0.05) with wet and dry uterine weights (r=0.36 and 0.47, respectively) and with total and average fetal weights (r=0.20 and 0.58, respectively) at week 15 of pregnancy. However, wet and dry uterine weights had high correlation with total fetal weight (r=0.97 and 0.95, respectively), without significant correlation with average fetal weight. It was concluded that during the embryonic stage of pregnancy, the levels of maternal progesterone were highly correlated with uterine and fetal growths, while during the fetal stage pregnancy, the correlation became less evident.