Inclusion Criteria:  Trial group:  The pregnant women in the middle and third trimester of pregnancy diagnosed by laboratory and B-ultrasound； The first singleton pregnancy, from 13 weeks to parturition； There are no pregnancy complications, the vital signs are stable, and the biochemical examination is normal; Patients who have informed consent to accept this pulse collection.  Control group:  Those who are included in the relatively healthy population are those with negative diagnostic criteria for early pregnant women; Patients who have informed consent to accept this pulse collection; The vital signs are stable, the biochemical tests are normal, and there are no severe brain, liver and kidney diseases.  Exclusion Criteria:  Trial group:  Pregnant women with ovarian, fallopian tube, uterine diseases, hypertension and diabetes during pregnancy; Definitely diagnosed patients with respiratory, cardiovascular, cerebrovascular, liver and kidney, blood, endocrine and other system diseases and severe infectious diseases; Those who have had a cesarean section or history of miscarriage; Those who have a serious illness and sit for less than 10 minutes in a quiet state; Patients with mental illness, depression, and cognitive impairment; Those who are not easy to collect pulse manifestation such as pulse on back of wrist and oblique-running pulse; Those who have incomplete information due to subjective or objective reasons that affect the result judgment; Patients with Parkinson's or other limb tremors.  Control group:  Those who have had a history of miscarriage or ectopic pregnancy; Patients with severe infectious diseases; Those who are not easy to collect pulse manifestation such as pulse on back of wrist and oblique-running pulse; The incomplete information affects the judgment of the result due to subjective or objective reasons; Patients with Parkinson's or other limb tremors; Menstrual women.