A boy is examined in the newborn nursery shortly after birth. He was born full term by vaginal delivery to a 40-year-old woman who did not receive prenatal care. His temperature is 36.7 C (98 F), pulse is 132/min, and respirations are 38/min. Examination shows slanted palpebral fissures, epicanthal folds, thick nuchal folds, and a single palmar crease. The patient has a large, reducible midline abdominal protrusion covered by skin that is more pronounced when he cries. The umbilical stump is at the center of the protrusion. Which of the following is the most likely cause of this patient's abdominal finding?

Question

A boy is examined in the newborn nursery shortly after birth.  He was born full term by vaginal delivery to a 40-year-old woman who did not receive prenatal care.  His temperature is 36.7 C (98 F), pulse is 132/min, and respirations are 38/min.  Examination shows slanted palpebral fissures, epicanthal folds, thick nuchal folds, and a single palmar crease.  The patient has a large, reducible midline abdominal protrusion covered by skin that is more pronounced when he cries.  The umbilical stump is at the center of the protrusion.  Which of the following is the most likely cause of this patient's abdominal finding?

Quizplus · Accepted Answer

11ec160b_3746_069a_9249_ab19aed8a02b_MD0001_00 This patient's examination is consistent with Down syndrome and an umbilical hernia. Normally, the umbilical ring, or the congenital fascial opening for the umbilical cord, closes and forms the linea alba, a midline band of fibrous tissue. Umbilical hernias are caused by an incomplete closure of the umbilical ring, thereby allowing protrusion of bowel through the abdominal musculature. Most umbilical hernias are reducible, asymptomatic, and resolve spontaneously in the first few years of life. (Choice A) During midgut development in the first trimester, the abdominal contents undergo physiologic herniation, followed by a rotation of the midgut and physiologic reduction. Failure of this reduction can result in omphalocele or gastroschisis. Omphalocele presents as a midline herniation of abdominal contents contained within a thin, membranous sac. Gastroschisis is a full-thickness abdominal wall defect that presents as an evisceration of exposed abdominal contents at birth. (Choice C) Midgut development in the first trimester involves a physiologic occlusion of the intestinal lumen followed by recanalization. Failure of recanalization results in duodenal atresia, which presents with vomiting, often bilious, in the first 24 hours of life. Duodenal atresia is associated with Down syndrome. (Choice D) Malrotation results from an incomplete rotation of the midgut prior to physiologic reduction into the abdominal cavity. Malrotation alone is asymptomatic. Its main complication is ischemia and subsequent small bowel necrosis due to volvulus, which twists and constricts the blood supply. Volvulus typically presents with bilious emesis in the first month of life. (Choice E) Congenital inguinal hernias are formed when the processus vaginalis, an outpouching of the peritoneum, fails to obliterate, leaving a path to allow bowel contents into the inguinal canal. The hernias present as a mass in the groin and are more common in preterm male infants. Like umbilical hernias, congenital inguinal hernias are more prominent with increased abdominal pressure. Educational objective: Umbilical hernias are caused by a defect in the linea alba and present as protrusions at the umbilicus that are soft, reducible, and benign. They can occur in isolation or in association with other conditions, such as Down syndrome. __________ References: Fetal abdominal wall defects. (http://www.ncbi.nlm.nih.gov/pubmed/24342556) Congenital and acquired umbilical hernias: examination and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/24597817)

A Boy Is Examined in the Newborn Nursery Shortly After