G6pc3^−/− mice exhibit reduced fertility. (A-C) Pup size and pregnancy intervals in wild-type and knockout matings. Sixteen pairs of wild-type and 16 pairs of knockout matings were set up with 8- to 10-week-old unaffected (+/+) and G6pc3^−/− (−/−) littermates. The pregnancy outcome was examined for 3 consecutive pregnancies. (A) The litter size. (B) Representative placentas at gestation day 15 in wild-type and knockout matings. (C) The intervals between the first 3 serial pregnancies. Values represent mean ± SEM. Data were measured for each pregnancy. (D) Representative IHC analysis of macrophages in the decidual region of the gestation day 15 placenta in wild-type (n = 8) and G6pc3^−/− (n = 8) matings at magnifications of ×400 and quantification of macrophage counts. Values represent mean ± SEM. Arrows denote macrophages. In wild-type placenta, numerous macrophages accumulated along the deciduas, and in G6pc3^−/− placenta few macrophages were seen. (E) Blood macrophage counts in wild-type (n = 8) and G6pc3^−/− (n = 8) mothers at gestation day 15, expressed as a percentage of total white blood cells. (F) Quantification of uterine MCP-1 and M-CSF mRNA in wild-type (n = 8) and G6pc3^−/− (n = 8) mothers at gestation day 15 by real-time RT-PCR. Levels are expressed as a ratio of uterine tissue to peritoneal macrophages. (G) Quantikine ELISA analysis of the levels of uterine MCP-1 and M-CSF in wild-type (n = 8) and G6pc3^−/− (n = 8) mothers at gestation day 15. (H) Uterine G6P, lactate, and ATP levels in wild-type (n = 8) and G6pc3^−/− (n = 8) mothers at gestation day 15. Data represent the mean ± SEM. **P < .005 and *P < .05.