EP08.13: Fetal inguinal hernia: a review of the literature

Congenital inguinal hernia (CIH) is a relatively prevalent pathology with a 3-5% incidence in term infants. However, fetal inguinal hernia (FIH) is a rare event, and only a few cases of prenatal diagnosis of the anomaly have been reported. We aim to characterise the sonographic features, clinical presentation, management, and outcome of FIH. We reviewed all cases of FIH published in the medical literature, including one new case evaluated by our group. All 17 cases (100%) were males in which the FIH presented as a scrotal mass of varying size, mean 38 ± 9.8MM. Most cases were diagnosed in the third trimester (88%) at mean gestational age of 33.1 ± 5.3W. The right side was dominant over the left and bilateral FIH (61.5%, 23%, and 15.5% - respectively). Peristalsis was reported in 80% of cases, and the presence of blood flow in two thirds. The ipsilateral testicle was observed in 30% of the cases and the contralateral in 100%. Sixty percent of the cases had isolated FIH, and two had minor malformations. In 3 / 17 cases (18%), the fetuses were syndromic, with multiple malformations: Trisomy 18, skeletal anomalies due to Jarcho-Levin syndrome, and undefined multiple joint contractures. Two cases (12%) had co-pathologies in the gastrointestinal tract; One had an echogenic bowel due to homozygosity to cystic fibrosis, and the other had low anorectal malformation. In both of these and in another isolated case (18%), bowel loop dilatation was observed prenatally. GA at delivery was 37.9 ± 1.8W, and the median time between diagnosis and delivery was 3W. All three cases of neonatal death occurred in syndromic fetuses. All the cases with non-syndromic CIH underwent definitive surgical repair at a median 14 days postpartum. No signs of strangulation and only one case with edematous bowel without necrosis were reported. FIH should be suspected when an intrascrotal mass with peristalsis is diagnosed during the third trimester. Close follow-up until term in the absence of signs of bowel obstruction is reasonable, and in isolated FIH, the prognosis is favourable.