Patients often come to the clinic with blood or ultrasound slips asking: Is my baby failing? Has he/she stopped growing? How do doctors determine when a baby has stopped growing? Is my baby stopped growing? 1. Calculate your true gestational week First of all, the doctor needs to know the number of days to conception, which is the gestational week. What doctors call the gestational week is based on a standard menstrual period, i.e. a menstrual cycle of 28 to 30 days. For example, if you have been menstruating for 8 weeks, if you have a regular menstrual cycle, then the number of weeks of menopause is what your doctor calls the gestational week, while if you have a 40-day menstrual cycle, then the number of weeks of menopause minus 1.5 weeks is your gestational week. This is a convenient way to calculate the week of pregnancy from your menstrual cycle, but there is also a big deviation. Nowadays, there are quite a lot of people who are counting their pregnancies, for example, by taking basal body temperature, using ovulation test strips, or having ovulation monitoring in the hospital, then the pregnancy week is calculated as: the number of weeks between the day of intercourse and the day of the visit + 2 weeks. In general, the gestational week is the basis for the doctor to determine whether the embryo is developing normally or not. With this basis, the doctor can generally determine whether the fetus is developing normally or not. Usually the fetal sac appears at 5 weeks and the fetal heart at 7 weeks. Then the criteria to determine the fetal stoppage must not be average, but the worst case. The first thing introduced is the gold standard for determining whether the embryo is developing normally – ultrasound. 2. The gold standard for diagnosing fetal arrest: ultrasound The early embryo observed under ultrasound will be divided into several parts: fetal sac, yolk sac, and fetal bud. The other parts will either gradually shrink (yolk sac) or become fetal accessories. There are three conditions that indicate fetal arrest: (1) a growing sac without a germ; (2) a germ that stops growing and never shows a fetal heart; (3) a germ that shows a fetal heart and then disappears. The presence of any of these three conditions is indicative of fetal arrest. The easiest way to understand fetal arrest in an ultrasound report is that the fetal heart goes from being present to absent. How is it determined by the mere presence of a long sac but no germ? If the average diameter of the gestational sac is ≥ 2.5 cm and no fetal bud appears, the diagnosis of fetal abruption is clear. It is very common in clinical practice to wait blindly for the gestational sac to grow to 5 cm and still wait obsessively, but it is not a minority. How to make a judgment on the delayed fetal heartbeat in time? If the gestational bud is greater than 7mm and there is no fetal heart, it means that the fetus is developing abnormally. In addition, the ultrasound often mentions the yolk sac, which is actually a nourishing fetal bud, if there is no fetal heart 11 days after the yolk sac, then do not continue to wait. 3, blood hcg does not fall is not the fetus is still alive HCG’s English name is human chorionic gonadotropin, in early pregnancy when HCG <5000-6000IU/L, it will double in 48 hours, and after that will continue to grow, but never flip again to flip long. However, there is a head of HCG rise, usually around 100,000, but also as high as 200,000. However, a rise in HCG means that the trophoblast cells that nourish the embryo are still alive, not that the embryo is still alive. In most cases of early embryonic arrest, the HCG drops and the early pregnancy reaction disappears, while in a few but not rare cases, the HCG continues to rise, the early pregnancy reaction remains, and the ultrasound already indicates fetal arrest. So never assume that the HCG is still rising and the fetus is still alive. Her fetal sac was larger than 2.5cm and there was no fetal bud after that, and the HCG never dropped during the 1 month waiting period. She was convinced that her baby was still growing, but in the end, she could not escape the end of fetal abortion. 4, blood progesterone decline does not always indicate the death of the fetus Progesterone is an important hormone to support pregnancy, in the early stages of early pregnancy is produced by the ovaries, this period it will fluctuate up, to 8-9 weeks of pregnancy, with the emergence and increase in the placenta, the placenta secretion of progesterone gradually increased, at this time the ovaries launched the historical stage, but in this task handover process will appear a small blood progesterone decline peak. Even if the fetus is alive, progesterone will not last long and slight fluctuations are possible. And conversely, after the fetus dies, it sends a message to the mother: "Don't give me nutrition! I'm no longer viable." So progesterone can be very low, usually below 5ng/dl, which mostly suggests fetal abortion. However, since many pregnant women are now using progesterone to preserve the fetus during early pregnancy, the significance of progesterone reading is greatly diminished. In general, the determination of fetal abortion should start from counting the gestational week, with ultrasound as the main line, and referring to blood HCG and progesterone.