For early pregnancy with preterm miscarriage and mid-late pregnancy with preterm preterm labor, both need to be treated with fertility preservation, and the methods to clarify whether the fertility preservation is successful or not are as follows: First, preterm miscarriage: 1, basic relief of lumbar soreness and abdominal pain: lumbar soreness, abdominal pain and other discomforts can gradually disappear, while perfecting the ultrasound examination can see the buds of the gestational sacs and the heart of the fetus, which indicates that the embryo is basically stable, and pregnant women can just carry out obstetric checkups on a regular basis; 2, decrease in vaginal bleeding and Decrease of secretion: if after the treatment of fetal preservation, there is no bloody secretion for 1 week in a row, it means that the condition of the fetus is basically stable; 3, the value of progesterone rises: for pregnant women with insufficient luteal function, if fetal preservation is successful, it means that the function of the placenta is recovering, and the placenta starts to replace the corpus luteum in the secretion of progesterone, so the value of progesterone rises gradually which shows that the placenta is stable, and the development of embryo is gradually stabilized. Second, preterm labor: 1, frequent contractions subside: if it has been more frequent contractions, after the use of uterine contraction inhibitors, the contractions significantly weakened and disappeared, the interval is gradually extended, and at the same time, it is not accompanied by shortening of the cervical canal and cervical dilatation or shortening of the length of the cervical canal, it can be regarded as the success of the birth control; 2, the results of the review is normal: in the birth control treatment for about one week, go to the hospital to review blood HCG and progesterone, the results are normal, and the results are normal, and the results are normal. Progesterone, the test results are normal, at the same time, ultrasound examination of fetal development is good, there is fetal heartbeat, that is to say, successful birth control, adhere to the regular obstetric examination can be.