Occult Tubo-Ovarian Abscess Diagnosed Intraoperatively During Urgent Cesarean Delivery: A Case Report

Introduction: Tubo-ovarian abscess (TOA) is an uncommon complication of pelvic inflammatory disease (PID), occurring in approximately 10-30% of women hospitalized with PID1. TOA during pregnancy is exceedingly rare and is described primarily in isolated case reports and small case series2. Reported cases are associated with significant maternal and fetal morbidity, including abscess rupture, sepsis, preterm delivery, and pregnancy loss2-6. Diagnosis may be particularly challenging in advanced gestation, as physiologic and anatomic changes of pregnancy can obscure both clinical and imaging findings3. Most published cases have occurred earlier in pregnancy, making third-trimester and term presentations especially uncommon6. We present a rare case of an occult TOA discovered intraoperatively during urgent cesarean delivery performed for suspected placental abruption and nonreassuring fetal status. Case Presentation: A 28 year-old G1P0 at 38 weeks and 2 days gestation presented with severe abdominal pain. Her pregnancy was complicated by class II obesity, pregestational diabetes mellitus requiring insulin therapy, and known abdominal trauma one week prior. Initial workup after the fall was negative for abruption. She was recommended for induction given late deceleration with nadir into the 80s during evaluation. Fetal heart tracing persistently category 2 with recurrent decelerations and persistent minimal variability. Ultimately, the patient was recommended for expedited delivery via cesarean. She received routine preoperative antibiotics. Laboratory evaluation revealed neutrophilia without leukocytosis. A markedly foul odor was noted upon entry into the abdomen. There was no evidence of placental abruption during delivery; however, a large right-sided TOA involving the right adnexa and adjacent bowel was identified. Intraoperative consultation was obtained, and right salpingo-oophorectomy, adhesiolysis, and abscess drainage were performed. Intraoperative cultures grew pansensitive Escherichia coli, pansensitive Pseudomonas aeruginosa, and Streptococcus constellatus. Postoperatively, she developed tachycardia but remained afebrile and was discharged on postoperative day four following multidisciplinary management and antibiotic therapy. Discussion: TOA during pregnancy is exceedingly rare, with published cases occurring predominantly in multiparous patients and earlier in gestation6. This case is notable for presentation at term in a nulliparous patient without a history of PID or known adnexal pathology. Pregestational diabetes may have increased susceptibility to infection despite the absence of traditional PID risk factors. Notably, the patient lacked classic infectious findings, including fever and leukocytosis, and the diagnosis was not suspected preoperatively. Furthermore, the TOA was not recognized on imaging or obstetric evaluations performed prior to delivery, underscoring the diagnostic challenges posed by advanced gestation. Visualization of adnexal structures may be limited in the third trimester, and significant pelvic infection may remain occult despite repeated assessments. This case also highlights the potential value of evaluating maternal adnexal structures when technically feasible during obstetric ultrasound examinations, particularly in patients with persistent abdominal pain or repeated presentations despite otherwise reassuring obstetric assessments. Instead, severe abdominal pain accompanied by recurrent fetal heart rate decelerations raised concern for placental abruption and prompted urgent cesarean delivery. The TOA was discovered only during surgical exploration. This presentation highlights how significant maternal intra-abdominal pathology may mimic obstetric emergencies and contribute to nonreassuring fetal status despite the absence of overt signs of infection. The markedly abnormal odor encountered upon entry into the abdomen provided an important clue to underlying pathology and reinforces the value of utilizing all available clinical observations during intraoperative assessment. Thorough inspection of accessible pelvic and abdominal anatomy during cesarean delivery may facilitate identification of unexpected pathology and timely multidisciplinary management. Despite postoperative cardiopulmonary concerns, including tachycardia and hypoxia, the patient improved with continued treatment and was discharged on postoperative day four, within the expected postoperative timeframe for cesarean delivery. Conclusion: Occult TOA may present at term without classic signs of infection and can mimic obstetric emergencies such as placental abruption. Awareness of this rare presentation may facilitate earlier recognition and management in pregnant patients with unexplained abdominal pain and nonreassuring fetal status.