A drop in hcg indicates that there are some problems with the placenta, because when a woman is newly pregnant, the value of hcg should keep growing until 8 weeks of pregnancy. And the growth rate is doubling every other day, and after reaching the peak value at 8-10 weeks it will slowly decline, eventually staying within about 10% of the peak value and not dropping significantly. If the hcg value is no longer increasing, you should pay attention to it, because it may be a sign of abnormal fetal development, and if the hcg drops too much beyond the fixed range, it will easily lead to fetal death and miscarriage.