Figure 2. Effect of maternal age on serum progesterone concentration.

Serum progesterone concentrations through gestation days 15 to 19 (D15–19) for 3‐month‐old (n = 8 for each day, open bars) and 8‐month‐old (n = 5–8 for each day, closed dark grey bars) pregnant mice. The 3‐month‐old mice had a significant reduction in serum progesterone concentration from day 15 of gestation to day 18 (^* P < 0.05); however, serum progesterone concentrations were similar throughout gestation (D15–19) for older mice. Data were analysed using ANOVA followed by an all pairwise multiple comparison Tukey's test and are presented as the mean ± SEM.