Female 32 years old, be admitted by “Amenorrhea 38 weeks and vaginal hemorrhagic secretions”. Physical examination: T 36.6℃ fetal position:LOA. FHR: 140. B ultrasound: BPD 9.0cm ,anterior placenta, gradeⅠ,2.8cm thickness, Ai 5.5cm. Due to human factor, the baby was born by caesarean section. Use azithromycin to prevent infection after operation. The temperature was between 38-39.3℃. Physical examination: no pharyngeal swelling and congestion, no rales, no abdominal pain, no tenderness and rebound tenderness. The contraction of uterus is well, scant lochia and no smell. The following examinations that we need to do the diagnose the disease? The diagnosis of the disease? How to treat the disease?