HCG rising from 6100 to 7100 in 48h is not a normal phenomenon, it could be fetal dysplasia or ectopic pregnancy. HCG is a glycoprotein hormone composed of α and β subunits, which is mainly secreted by placental trophoblast cells formed after a woman’s pregnancy. Trophoblast cells begin to produce HCG after the fertilized egg is deposited and it can be measured in the mother’s serum on the 1st day, and then it rises twice as much every 1.7-2 days, and it reaches about 100 IU/L on the 14th day after ovulation, and it reaches the peak in the 8-10th week of gestation, and then it declines rapidly, and it disappears in the 2 weeks after delivery. HCG has risen slowly from 6100 48 hours ago to 7100 without doubling, it is possible that the embryo is underdeveloped or ectopic pregnancy. No matter what the case is, HCG rising slowly, it is necessary to consult the doctor in time to clarify the diagnosis and then proceed to the next step of treatment.