Ureaplasma urealyticum positivity is caused by the infection of the human body with Ureaplasma urealyticum. Ureaplasma urealyticum is a common pathogenic mycoplasma that causes inflammatory lesions in the genitourinary tract, including non-pathogenic urethritis, pelvic inflammatory disease, cervicitis, endometritis, prostatitis, and epididymitis. Moreover, Ureaplasma urealyticum infection has an effect on sperm production, swimming and the union of sperm and egg, which can lead to male infertility and female infertility. Infection in pregnant women can lead to miscarriage, excessive amniotic fluid, gestational toxicity, premature birth, premature rupture of membranes and chorioamnionitis, etc. It can also lead to fetal infection via blood flow, resulting in fetal malformation, congenital heart disease, stillbirth, etc.