The examination items in the fifth month of pregnancy generally include general examination, auxiliary examination, gynecological examination and special examination, mainly to evaluate the fetal development and maternal health status. 1. general examination: including measurement of height, weight, blood pressure, as well as uterine height and abdominal circumference; 2. auxiliary examination: including routine blood, urine routine, liver function, kidney function, hepatitis B antibody test, etc. Ultrasound examination: Ultrasound examination of fetal system can screen fetal structural malformations, such as congenital heart disease, atrial septal defect, ventricular septal defect, arteriovenous ductus arteriosus and tetralogy of Fallot, as well as detection of malformations of various systems such as urinary, reproductive, digestive and neurological. In addition, the position of the placenta can be checked to find out whether there is placenta praevia, placenta abruptio, etc.; 4. Gynecological examination: intravaginal examination includes understanding whether there are abnormalities in the vagina and cervix, checking whether the degree of uterine enlargement matches the gestational week, checking whether there are abnormalities in the uterus and ovaries, and checking vaginal discharge to determine whether there are infections such as bacteria, trichomonas and mycobacteria. In addition, pregnant women with a history of preterm labor or late miscarriage and those with symptoms of preterm labor should also have their cervical canal measured to determine whether preterm labor may occur; 5. Special tests: such as amniocentesis or non-invasive DNA testing, mainly used to diagnose chromosomal and genetic abnormalities, generally for pregnant women who are older than 35 years old or have a clear family history of genetic diseases.