Nowadays, conceiving a baby is a seemingly simple but not easy task, not only to conceive successfully, but also to have a healthy pregnancy and a smooth delivery. In our own department, there are many patients who come to the clinic every day for the purpose of preserving the pregnancy. Some patients with pre-eclampsia miscarriage fail to pay attention to it in the early stage, and already have abdominal pain and vaginal bleeding without coming to the clinic, which delays the best treatment period and causes irreparable regret. Therefore, early detection and treatment of pre-eclampsia is needed. The answer is no. The following is an introduction to the people who need birth control, women who are already pregnant and those who are preparing for pregnancy to understand it. 1. Advanced Pregnancy With the opening of the second child policy, more and more families are ready to welcome their second child, but age is a factor that needs special attention for women who are pregnant. 35 years old and later, the ovarian function of women declines rapidly and the luteal function becomes poor, which will not only cause infertility, miscarriage, fetal malformation, but also cause premature birth of the fetus, so it is recommended that advanced pregnant women need birth control. 2. Pregnant women with a history of spontaneous miscarriage, embryonic development arrest, etc. Those who have a history of bad pregnancy and delivery before, including those who found the cause of miscarriage, embryonic abortion and some who did not find the cause, this group of people need to focus on birth control. In my opinion, it is best to keep the pregnancy for more than a few months after the last miscarriage or embryonic arrest, and the maximum time is usually 3-5 months. 3. Pregnant women with a history of infertility Many women initially visit the clinic for infertility, but after successful treatment and conception, they do not follow up in time and come back to the clinic after miscarriage or fetal failure, which is too late. There are many causes of infertility, all of which may cause fetal failure and are potential factors for miscarriage, for example, patients with polycystic ovary syndrome are not easy to conceive and are prone to miscarriage after conception. 4. Pregnant women after in vitro fertilization The world’s first in vitro fertilization baby was born in 1978 in England. IVF in China started in March 1988, when Professor Zhang Lizhu, a famous Chinese obstetrician and gynecologist, pioneered the first IVF case in China at the Third Hospital of Peking University. While IVF has certainly brought hope to many infertile families, not every case can be successful and not every case can be conceived successfully. For families undergoing IVF, the status of the egg retrieval, before and after embryo transfer is important, and women with embryo transfer are more likely to have a pre-term miscarriage. Therefore, it is recommended that mothers with a thin lining and a history of pre-eclampsia need to be kept in labor, and if abdominal pain and vaginal bleeding occur, they should be seen immediately. 5. Pregnant women with preterm miscarriage If the above symptoms occur mothers must not panic, due to timely access to the hospital, the doctor will give the correct advice according to each person’s situation, to develop a plan to keep the baby. NOTICE: Not all pregnant women with the above mentioned factors should be on birth control, if the doctor recommends giving up, it means the embryo may stop developing or be stunted. If the embryo has stopped developing, it should be removed in time so that the embryo will not stay too long and cause harm to the mother. It is not necessarily a bad thing that the embryo stops developing, as it is often said that the survival of the fittest, after all, every mother wants to have a healthy baby. I would like to remind all mothers who are preparing for pregnancy and those who are already pregnant to monitor their blood hormone levels dynamically during pregnancy and to perform ultrasound if necessary, so that your doctor can give you a good advice based on the blood hormone levels and ultrasound results.