[Development of estradiol, progesterone, and prostaglandins E and F2 alpha levels during pregnancy in mice].

17 beta estradiol, progesterone, prostaglandin E and prostaglandin F2 alpha were determined in the plasma of mice at different times of pregnancy. Estradiol displays a preimplantation peak on day 4. Other peaks are visible at the end of the implantation period (day 6) and on day 10. Progesterone increases when implantation begins (day 5). Prostaglandins increase at the beginning of pregnancy and decrease temporarily before implantation. Other peaks are also apparent for prostaglandin E on days 5.5 and 11.