Progesterone 17ng/ml on day 35 of pregnancy may preserve the fetus, and should be actively treated to preserve the fetus. After pregnancy serum progesterone will gradually rise with the increase of gestational weeks, 35 days pregnant when the normal value of progesterone between 20 to 25 ng / ml, when the progesterone test for 17 ng / ml suggests that the value of progesterone is low, may increase the risk of early miscarriage, need to comply with the doctor’s instructions to give progesterone and other drugs to protect the fetus treatment, most of them can be successful in preserving the fetus, but there will be individual differences. Early pregnancy should also pay attention to appropriate rest, prohibit coitus, avoid exertion and strenuous exercise, continue to follow the doctor’s advice to take folic acid treatment, but also according to their own response to the appropriate increase in nutrition. When abdominal pain, vaginal bleeding and other symptoms of preeclampsia, you need to carry out ultrasound to understand the development of the embryo, and follow the doctor’s advice to actively preserve the fetus treatment.