A 17mm echogenic area in the uterorectal fossa is considered to be fluid retention. It may be physiologic pelvic fluid, or it may be caused by pelvic inflammatory disease, ectopic pregnancy and so on. 1. Physiologic pelvic fluid: In general, there will be a small amount of physiologic pelvic fluid in the uterorectal fossa, usually no discomfort, no special treatment. 2. Pelvic inflammatory disease: if pelvic fluid, accompanied by abdominal pain, leukorrhea yellowish increase, considering pelvic inflammatory disease, because acute pelvic inflammatory disease can cause pelvic fluid, then need to be actively symptomatic treatment, in order to avoid the development of chronic pelvic inflammatory disease, can be used to anti-infective treatment, such as drip metronidazole and ampicillin, and at the same time oral gynecological Qianjin tablets and other symptomatic treatment. 3. Ectopic pregnancy: The rupture of ectopic pregnancy often produces pelvic effusion, but usually there will be menopause, abdominal pain, vaginal bleeding and other clinical symptoms. It is recommended that women with unexplained pelvic effusion should first undergo gynecological examination, ultrasound, combined with medical history and blood test for HCG to rule out ectopic pregnancy, such as pelvic inflammatory disease, ectopic pregnancy, etc. should be treated promptly. Pelvic fluid, accompanied by abdominal pain, vaginal bleeding and other discomforts should be followed up promptly.