In addition to home pregnancy tests, what other medical scenarios can HCG pregnancy tests be used in?

In addition to home pregnancy tests, HCG pregnancy tests are also widely used in the following medical scenarios:
I. Clinical diagnosis and treatment in obstetrics and gynaecology
Assisted Reproductive Technology (ART) Monitoring
HCG testing is crucial in assisted reproductive processes such as In Vitro Fertilisation – Embryo Transfer (IVF – ET). HCG levels in the patient’s blood are usually closely monitored by the doctor after the embryo transfer. The test is usually done around 10 – 14 days after the transfer and if HCG is detected to be elevated, this may be a sign of successful embryo implantation. For example, in IVF treatment, the dynamic changes in HCG can be detected to determine the embryo’s implantation and early developmental status, which will provide the basis for subsequent luteal support treatment, etc., in order to improve the pregnancy success rate.
Miscarriage risk assessment and management
For pregnant women with symptoms of pre-eclampsia such as vaginal bleeding and abdominal pain, testing HCG levels can help doctors assess the risk of miscarriage. In early pregnancy, HCG levels in a normal pregnancy should show a rapid increase. If HCG levels are increasing slowly or dropping, it may indicate abnormal embryo development or an impending miscarriage. Based on the changes in HCG levels, combined with ultrasound examination and other means, the doctor can decide whether it is necessary to take measures to protect the foetus, such as giving progesterone and other medications to treat it.
Monitoring of pregnancy complications
During pregnancy, certain complications can lead to abnormal HCG levels. For example, in cases of placental abruption or placental insufficiency, the HCG level in the blood of a pregnant woman may change. Through regular HCG testing, doctors can detect these abnormalities in time so that appropriate treatment measures can be taken. For example, for pregnant women with placental insufficiency, it may be necessary to increase the frequency of prenatal check-ups, keep a close watch on the foetus, and terminate the pregnancy in advance if necessary to ensure the safety of both mother and baby.
Second, differential diagnosis of pregnancy abnormalities
Diagnosis and management of ectopic pregnancy
Ectopic pregnancy is one of the common acute abdominal diseases in obstetrics and gynaecology, and early diagnosis and management are crucial. As the fertilised egg in ectopic pregnancy is deposited outside the uterine cavity, its trophoblast cells are not well developed, resulting in HCG level usually lower than that of normal intrauterine pregnancy. By testing for HCG in the blood and urine, combined with ultrasound, doctors can improve the early diagnosis of ectopic pregnancy. Once the diagnosis of ectopic pregnancy is confirmed, appropriate treatment options, such as medication or surgery, need to be chosen based on the patient’s specific condition (e.g. presence of intra-abdominal bleeding, size of the mass, etc.).
Diagnosis and treatment of hyperemesis gravidarum and trophoblastic diseases
Hyperemesis gravidarum is a benign trophoblastic disease in which the uterus is filled with blister-like tissue instead of normal embryonic tissue. In hyperemesis gravidarum, HCG levels are significantly elevated and are usually much higher than normal for the same pregnancy. A test of HCG, combined with an ultrasound, can help the doctor make a prompt diagnosis of hyperemesis gravidarum. Once the diagnosis is made, a surgical evacuation of the uterus is required to remove the abnormal tissue from the uterus. In addition, for malignant trophoblastic diseases such as choriocarcinoma and erosive staphylococcus, HCG testing is a key indicator in the diagnosis, treatment and follow-up process. During the course of treatment, changes in HCG levels can be monitored to assess the effectiveness of the treatment. A sustained decrease in HCG after chemotherapy indicates that the treatment is effective, while a decrease followed by an increase in HCG may indicate a recurrence of the disease.
Monitoring after gynaecological surgery and disease treatment
Pregnancy-related monitoring after gynaecological surgery
Some gynaecological surgeries (e.g. myomectomy, endometriosis surgery, etc.) may cause some damage to the uterus or adnexa, affecting subsequent pregnancy. During post-operative pregnancy preparation, HCG test can detect whether pregnancy is successful or not. For patients who become pregnant after surgery, HCG testing can also help to monitor whether the pregnancy is progressing normally, as factors such as surgical scarring may increase the risk of miscarriage and ectopic pregnancy.
Follow-up after treatment of certain gynaecological conditions
After treatment for some reproductive-related conditions, such as polycystic ovary syndrome (PCOS), where ovulation and pregnancy have been successfully achieved after medication, HCG testing can be used to monitor the progress of the pregnancy. In addition, in women who have undergone chemotherapy or radiotherapy and become pregnant after treatment, HCG testing is important to assess the health of the foetus and whether the pregnancy is going well.