Idiopathic origin of meconium peritonitis

A 26-year-old, gravida 3 presented at 31 weeks of gestation with polyhydramnios. On ultrasound there was marked foetal ascitis with unilateral hydrocele. Patient delivered a 3.15 kg, large-for-date baby at 33 weeks and 3 days of gestation. On basis of clinical, radiological and sonographic features, diagnosis of meconium peritonitis was made. Ascitic tapping was done. Surgery was withheld, as there were no signs of intestinal obstruction. DNA testing for cystic fibrosis was negative. Baby did not deteriorate so he was discharged. Baby was doing well on 2 months follow up. Hydrocele and ascitis were resolving. Rarely meconium peritonitis may occur without an underlying cause when peritonitis may be innocuous and intervention may not be required.