Female Reproductive Failures in Mouse Adolescent Pregnancy

Abstract Background: There are around 300 million adolescent pregnancies worldwide, accounting for 11% of all births worldwide. Accumulating evidence demonstrates that many adverse perinatal outcomes are associated with adolescent pregnancies. However, how and why these abnormalities occur remain to be defined. Methods: To compare uterine maturity, implantation, decidualization and placental development between 25-30 days old and 3 months old mature female CD-1 strain mice. Both in vivo mouse pregnancy and in vitro cell culture were used. Western blot, real time RT-PCR, immunostaining and immunofluorescence were used to study the progress of pregnancy during two groups.Results: We found the litter size of adolescent pregnancy is significantly decreased from F1 to F3 generations compared to mature pregnancy. On days 8 and 12 of pregnancy, multiple abnormalities in placental and decidual developments appear in F3 adolescent pregnancy. On days 5 and 8, uterine endoplasmic reticulum stress is dysregulated compared to mature pregnancy. Embryo implantation and decidualization are also compromised in adolescent pregnancy. Many genes are abnormally expressed in adolescent estrous uteri. Conclusion: The uterine immaturities and abnormal implantation may cause multiple pregnancy failures in adolescent pregnancy.