For some reason ectopic pregnancies are becoming more and more commonplace, and often patients come to the clinic or emergency room nervous about a small amount of bleeding or minor abdominal discomfort, fearing that they have an ectopic pregnancy. As mentioned in the previous article “Where are you carrying your baby”, ultrasound cannot locate the pregnancy at this time because it is still early. So what other tools are available to the ultrasound doctor to identify an ectopic pregnancy at an early stage? First of all, look at the blood hcg, which is not possible in a single test. If it doubles, then 80-90% of the pregnancy is intrauterine. However, there are some unexpected cases: firstly, when the pregnancy week is big, the hcg will not grow so fast after it is more than 5000. Secondly, the hcg can’t be doubled so much when the development of intrauterine pregnancy is not good. Also we have to look at the blood progesterone, if the progesterone is more than 25ng/dl, then 98% of them are intrauterine pregnancy. Here there will be 2-3% of well-developed ectopic pregnancies that will have this phenomenon. To summarize: before the ultrasound can see where the embryo is in the bed, if the hcg doubles 48 hours apart or if the single progesterone value is greater than 25ng/dl is suggestive of a well-developed intrauterine pregnancy. With these two tools, you can look for traces of embryonic development and in most cases make a more accurate judgment. Of course, there are exceptions to everything, so close observation and dynamic monitoring are believed to ensure a safe pregnancy can be achieved.