1.Low sperm, weak sperm and deformed sperm in men (low sperm count, low viability and high malformation rate); 2.Cervical factors in women such as cervical scars, cervical tumors, cervical inflammation (difficult for sperm to pass through); 3.Vaginal abnormalities leading to inability to have intercourse (vaginal scar, vaginal malformation, vaginal contracture due to psychological tension); 4.Inability to deliver sperm into women’s vagina due to male factors (various factors leading to inability to have intercourse, hypospadias, excessive penile curvature, etc.); 5.Immune infertility; 6.Unexplained infertility (no obvious abnormality found in both male and female partners during clinical examination, ineffective after simple clinical treatment).