The overall prognosis of PID is good. Timely, appropriate treatment often prevents serious complications such as ectopic pregnancy, infertility, hydrosalpinx, and chronic pelvic pain.

If left untreated, PID may lead to infertility in approximately 16% of affected women.^[1] It may progress to adjacent organ involvement or even peritonitis.

The overall prognosis of PID is good if patients are treated within 3 days of the onset of symptoms onset, though clinical improvement cannot guarantee protection against infertility.^[2]

Factors that predict poor prognosis include:^[3]

• Advanced age
• History of previous open gynecological surgery
• Any cystic lesion identified by ultrasonography
• High CRP levels

• Chronic pelvic pain is defined as lower abdominal pain that lasts for at least 6 months and causes functional disability. Approximately 1 in 3 of women affected by PID will experience chronic pelvic pain.^[4]
• Recurrent PID is the strongest predictor for the development of chronic pelvic pain due to the scars and adhesions that result from repeated inflammation.^[5]

• PID may cause permanent damages to the fallopian tubes, this damages include loss of ciliary action, fibrosis, and occlusion that may result in infertility.^[6]
• Risk factors for infertility include:
  1. Chlamydial infection^[7]
  2. Delayed PID treatment^[8]
  3. Frequent PIDs^[9]
  4. Severity of infection^[10]

• Tubal damage due to PID may result in anatomical distortion, which can predispose the patient to ectopic pregnancy.^[1]

• Tubal damage may lead to tubal blockade, sterile fluid accumulation, and/or fallopian tube enlargement, which may cause pain or infertility.^[11]

• Inflammation and adhesion formation in the liver capsule (perihepatitis) may cause right upper quadrant abdominal pain and tenderness.^[12]