Saran is a hard-working white-collar worker with a happy life. She has been preparing for pregnancy for 3 months to welcome her little angel. This month, when her period was due to come or not, Saran was excited to use the early pregnancy test and found a faint “mid-captain” line! Saran went to the hospital for a checkup and the doctor told her that it was a biochemical pregnancy, so she was confused! What is a biochemical pregnancy? A biochemical pregnancy is an early miscarriage that occurs within 5 weeks of gestation, where an elevated HCG level of more than 25 mlU/mL can be detected in the blood or a positive urine pregnancy test, but the gestational sac is not visible on ultrasound, which is now medically known as a “subclinical miscarriage”. Biochemical pregnancies are not uncommon and account for about 25-30% of all pregnancies. Without a specific HCG test, some women may just think that their period is delayed once and not realize that it is a biochemical pregnancy. How can a biochemical pregnancy occur? In a normal pregnancy, the sperm and egg unite in the fallopian tube to become a fertilized egg, which then returns to the uterus to settle and develop into a fetus. In the case of a biochemical pregnancy, the sperm and egg are united but do not return to the uterus for implantation, or they enter the uterus and do not come to bed. A biochemical pregnancy is likely to occur when: 1. the fertilized egg itself is defective: it is generally believed that chromosomal abnormalities in the embryo may be the main cause of a biochemical pregnancy. More than 50% of early miscarriages in the first trimester are due to chromosomal abnormalities. 2, poor ovarian corpus luteum function: poor corpus luteum, resulting in insufficient luteinizing hormone secretion and abnormal endometrium, will affect the fertilization of the egg in the uterus. 3, uterine factors: uterine dysplasia, submucosal fibroids, endometrial polyps, uterine adhesions, endometrial tuberculosis, etc. affect the fertilized egg’s fertilization. 4, immune factors: there are two kinds of immune conditions that affect fertilization, one is alloimmune: sperm, seminal plasma or fertilized eggs are antigenic substances, which are absorbed by the vagina and uterine epithelium and produce antibody substances through immune reactions, so that sperm and eggs cannot combine or fertilized eggs cannot implant; the other is autoimmune: it is believed that there are autoantibodies to zona pellucida in the serum of infertile women, which can prevent sperm from penetrating the egg after reacting with zona pellucida, thus preventing fertilization. The other is autoimmunity: it is believed that the presence of autoantibodies to the zona pellucida in the serum of infertile women prevents sperm from penetrating the egg and thus prevents fertilization. 5, excessive mental stress: especially severe anxiety and psychological stress due to the lack of pregnancy. In essence, biochemical pregnancy is a kind of natural selection of superiority and inferiority, so if you encounter such a situation, there is no need to be too nervous, no treatment or therapy is needed, and it usually does not affect the next pregnancy. If this happens several times, it is necessary to go to the hospital for further detailed examination to find out the cause of the problem and provide targeted treatment. Depending on your condition, your doctor will perform tests for endometrial tolerance, luteal function and immune factors such as closed antibodies and unique antibodies, as appropriate. Are biochemical pregnancy and miscarriage the same thing? Biochemical pregnancy and miscarriage are both pregnancy failures. Some young mothers think that biochemical pregnancy is a miscarriage, are they the same thing? In fact, a biochemical pregnancy is a pregnancy that has progressed only to the stage where it can be detected by biochemical methods and has not progressed to the stage where the gestational sac can be diagnosed by ultrasound, and can be considered a special type of early pregnancy loss. Miscarriage, on the other hand, is an event that occurs after embryo implantation and is a clinical pregnancy loss. Therefore, both biochemical pregnancy and miscarriage fall under the category of embryonic or pregnancy loss, but they occur at different physiological stages, so they are not the same thing. How long after a biochemical pregnancy can I get pregnant again? There are no special rules in this regard. If you are not in a hurry to have a baby, you may consider taking a break of 3 to 6 months to allow the uterus to have enough time to “rest” and to improve its condition that led to the miscarriage and to get rid of the external environment that is unfavorable to the development of the embryo.