A New Association of Second-Trimester Echogenic Bowel and Metabolic Disease of the Neonate

Abstract

Fetal echogenic bowel is diagnosed in 0.2% to 1.4% of second-trimester ultrasound examinations. 1 It is a nonspecific finding that refers to an increase in echogenicity, or brightness of the fetal bowel, similar to or greater than that of adjacent bone, when the ultrasound gain is turned down to the lowest setting possible. Its presence in the second trimester has been described in association with healthy fetuses, as well as aneuploidy, cystic fibrosis, intrauterine growth restriction, intra-amniotic bleeding, congenital infections, thalassemia, and poor pregnancy outcome. 2,3 Abnormal elevation of maternal serum markers in the second trimester, including α-fetoprotein (AFP) and human chorionic gonadotropin (hCG), along with echogenic bowel have also been associated with adverse perinatal outcomes, including intrauterine fetal death, fetal growth restriction, abruptio placentae, preterm birth, premature rupture of membranes, and pregnancy-induced hypertension. 4-10 However, elevated second-trimester hCG levels with echogenic bowel has not been clearly identified as a risk factor for neonatal mortality, nor has there been any previous association with metabolic disease of the neonate. We describe 2 cases of echogenic bowel associated with elevated maternal serum hCG levels resulting in neonatal mitochondrial trifunctional protein deficiency or long-chain 3-hydroxylacyl-coenzyme A dehydrogenase (LCHAD) deficiency and neonatal deaths.