Vernix Caseosa Peritonitis: A Scoping Review

Background and Objectives: Vernix caseosa peritonitis (VCP) is rare. Nonspecific symptoms of acute abdomen during early puerperium make preoperative diagnosis of VCP challenging. We aimed to identify risk factors, early diagnosis and treatment options, and the association between the timing and severity of VCP diagnosis and maternal outcomes. Materials and Methods: We searched PubMed, PubMed Central, and Google Scholar. Articles were analyzed according to the PRISMA guidelines. The search items included: 'vernix caseosa peritonitis, 'vernix caseosa granuloma, 'maternal meconium peritonitis', 'maternal meconium granuloma', 'vernix caseosa', 'peritonitis', 'pregnancy', 'puerperium', 'postpartum', and 'gravid'. Additional studies were extracted by reviewing the reference lists of retrieved studies. Demographic, clinical, obstetric, diagnostic, and treatment parameters, and outcomes were collected. Results: Out of 55 published VCP case reports, 46 were available. Most involved term pregnancies (84.8%) and were delivered by Cesarean section (CS) (87%), with no difference in parity distribution (χ²(2) = 1.1875, p = 0.5523) or fetal sex (m: f = 53.3%: 46.7%). Common symptoms included abdominal pain and fever over 38 °C, while dyspnea or tachypnea was unexpectedly frequent (23.9%/15.2%). The interval from delivery to surgery ranged from 4 to 13 days (average 8 days), with no difference between CS and vaginal deliveries. Preoperative VCP was diagnosed in only 4.3% of cases, and intraoperative diagnosis occurred in 60.9%. Intraoperative microbiology and histopathology (vernix components) were positive in 6.5% and 89.1%, respectively. The birth weight was normal (3656 ± 509 g), with no maternal or neonatal deaths. Conclusions: VCP primarily develops in term pregnancies delivered by CS, without other risk factors. Despite extremely low preoperative and unexpectedly low intraoperative diagnosis and treatment delay of several days, there is no maternal or fetal mortality. The time to symptom onset is similar between women who delivered vaginally and those who had a CS. All women with VCP after vaginal delivery had previous deliveries. Abdominal pain with a fever over 38 °C and dyspnea or tachypnea in the early puerperium suggests VCP. Surgical lavage is the primary treatment, while corticosteroids have been reported to be beneficial in several cases, and antibiotics seem to have a limited role.