Diagnosis and management of ectopic pregnancy An ectopic pregnancy is a pregnancy in which the fertilized egg lodges in any part of the body other than the normal uterine cavity. Ectopic pregnancy can be life-threatening and has received widespread attention from clinicians as a common gynecologic emergency. Ectopic pregnancy has become a worldwide epidemic, with approximately 2 out of 100 pregnancies in the United States being ectopic pregnancies. Currently, due to the widespread use of ultrasound, blood β-HCG measurement and laparoscopic diagnosis, 80% of ectopic pregnancies can be diagnosed before they rupture. 1. Clinical diagnosis There is no difficulty in clinical diagnosis when ectopic pregnancy is miscarried or ruptured with a large amount of intra-abdominal bleeding and typical symptoms and signs. However, these late cases are now increasingly rare in clinical practice, and are estimated to account for only about 20% of cases. It is more common to see early unruptured ectopic pregnancies, where it is difficult to determine the pregnancy and the site of pregnancy by clinical examination alone. It is generally believed that the accuracy of diagnosing ectopic pregnancy by clinical examination alone is only about 50%. (2) Auxiliary diagnosis (1) HCG measurement: HCG can be measured in normal pregnancy about 7~10 days after ovulation, and HCG secretion increases rapidly in the first 3 weeks, doubling in about 1.7 days; doubling in about 3 days in the 4th~10th weeks, and the blood HCG reaches more than 1000miu/ml in the 5th week of pregnancy, and reaches the peak in the 8th~10th weeks of pregnancy. Dynamic observation of blood HCG level should increase by at least 66% in 2 days. The ectopic pregnancy blood HCG level is low and the doubling time (doubling time) is prolonged for about 3 days~8 days, with an average of 7 days. However, low HCG levels or prolonged doubling time are also seen in preterm or inevitable miscarriages. It is important to note that the half-life of blood HCG is 37 hours, so the measured blood HCG results do not reflect the activity of trophoblast cells on the day of blood collection. In addition, measurement of blood HCG level is often not available in a short period of time, which will prolong the time to confirm the diagnosis. Our department reported a trial of HCG rapid semi-quantitative determination plate method, which is quick and easy to detect blood HCG level with high reliability and can be tested at any time, which is very helpful for early diagnosis of ectopic pregnancy and timely guidance of treatment. (2) Diagnosis by imaging . The accuracy of ultrasound diagnosis of ectopic pregnancy can reach 70%~92.3%, and its most important feature is that it can detect or exclude intrauterine pregnancy, and if an intrauterine pregnancy is found, it is very unlikely that the patient will have another ectopic pregnancy, because the incidence of intrauterine ectopic compound pregnancy is only 1:30,000, which is quite rare. The tubal ring, which is decisive for the diagnosis of tubal pregnancy, is an ultrasound image of a 1-cm to 3-cm diameter ring outside the ovary, with a wall thickness of about 2 mm to 4 mm consisting of chorionic tissue and the wall of the fallopian tube, reflecting higher than the normal ovary or the corpus luteum of pregnancy, with a central cystic anechoic area (gestational sac). The specificity of the tubal ring for the diagnosis of unruptured tubal pregnancy is 99.5%-100%, and tubal rings have been reported to be visible on ultrasound in 86 ectopic pregnancies. In about 10%-20% of ectopic pregnancies, due to metaplastic changes in the endometrium and accumulation of blood in the uterine cavity, an elliptical liquid dark area, called a pseudogestational sac, can be seen on the ultrasound image. 5%-20% of gestational sacs, embryonic buds and fetal heartbeats can be seen outside the uterus. Ultrasonography combined with blood HCG measurement can improve the diagnosis of ectopic pregnancy. Blood β-HCG should be higher than 6500miu/ml when a gestational sac is seen on abdominal ultrasound, and higher than 2000miu/ml when a gestational sac is seen on vaginal ultrasound. If blood β-HCG is higher than 6500miu/ml and no gestational sac is seen in the uterus, or if a cystic cavity is seen in the uterus and blood β-HCG is consistently lower than 2000miu/ml, the possibility of ectopic pregnancy should be considered. The superiority of vaginal ultrasound is that the gestational sac can be seen at 5 weeks of gestation and the ability to discriminate between ectopic pregnancy masses is higher than that of abdominal ultrasound. Color ultrasound of the endometrium and myometrium without increased restrictive blood flow also suggests the possibility of ectopic pregnancy, and intravenous enhancers can be administered to make the circumferential blood flow around the trophoblastic tissue easier to identify and improve the sensitivity of the ultrasound diagnosis. Some authors have reported a higher accuracy rate for the diagnosis of ectopic pregnancy with magnetic resonance imaging (MRI), although it is not widely available because of its high cost. (3) Diagnostic curettage. Because of its simplicity and ease of use, it still plays an important role in the diagnosis of ectopic pregnancy. The main purpose of diagnostic curettage is to detect intrauterine pregnancies, especially abnormal pregnancies such as pre-eclampsia or refractory miscarriage with poor trophoblast development, low HCG secretion and no obvious gestational sac on ultrasonography. The clinical presentation of such pregnancies and ectopic pregnancies are very similar and can be easily misdiagnosed as ectopic pregnancies, which may be treated by doctors with MTX. However, MTX should not be used to treat intrauterine pregnancies and is not effective. Therefore, in patients with suspected ectopic pregnancy whose blood HCG level is below 2000 miu/ml and who have a request for termination of pregnancy, diagnostic scraping should be performed and the scrapings should be sent for pathological examination after visual inspection, and if villi are found, intrauterine pregnancy can be confirmed without further treatment. If no villi are found in the scrapings, and if the blood HCG level does not decrease significantly or continues to rise on the next day of the scraping procedure, ectopic pregnancy is diagnosed. (4) Posterior fornix or laparotomy. The rate of misdiagnosis is about 10%. In developed countries, this test tends to be eliminated because ultrasonography has become common. In some hospitals in China, posterior fornix or laparotomy is still often used to assist in the diagnosis of internal bleeding in ectopic pregnancy because ultrasonography is not common enough. (5) Progesterone determination. Progesterone is relatively stable at 5 to 10 weeks of gestation, and the level of ectopic pregnancy is low and does not correlate with blood HCG level. In recent years, many scholars at home and abroad believe that blood progesterone measurement is of great value in the diagnosis of abnormal pregnancy including ectopic pregnancy, and its value is second only to blood HCG. e.g. progesterone at 8 weeks of gestation