A term newborn is evaluated in the nursery 1 hour after a spontaneous vaginal delivery to a 28-year-old primigravida whose pregnancy was uneventful. The patient's Apgar scores were 9 and 9 at 1 and 5 minutes, respectively. Vital signs are normal. Physical examination shows a newborn sleeping comfortably with overlapping coronal sutures. There is a I/VI systolic murmur at the left upper sternal border that radiates to the axilla. The lungs are clear bilaterally. The abdomen is soft, and the liver is palpable 2 cm below the costal margin. Genitourinary examination shows curvature of an underdeveloped penis. The urethral meatus is at the ventral surface of the base and flanked by the surrounding scrotal sac. Gonads are not palpable. Examination of the back shows a sacral dimple with intact skin. The patient has normal fingers and toes. There is cyanosis in the digits. There is symmetric movement of all 4 extremities, and Moro and suck reflexes are normal. Which of the following is the best next step in evaluation of this patient?

Question

A term newborn is evaluated in the nursery 1 hour after a spontaneous vaginal delivery to a 28-year-old primigravida whose pregnancy was uneventful.  The patient's Apgar scores were 9 and 9 at 1 and 5 minutes, respectively.  Vital signs are normal.  Physical examination shows a newborn sleeping comfortably with overlapping coronal sutures.  There is a I/VI systolic murmur at the left upper sternal border that radiates to the axilla.  The lungs are clear bilaterally.  The abdomen is soft, and the liver is palpable 2 cm below the costal margin.  Genitourinary examination shows curvature of an underdeveloped penis.  The urethral meatus is at the ventral surface of the base and flanked by the surrounding scrotal sac.  Gonads are not palpable.  Examination of the back shows a sacral dimple with intact skin.  The patient has normal fingers and toes.  There is cyanosis in the digits.  There is symmetric movement of all 4 extremities, and Moro and suck reflexes are normal.  Which of the following is the best next step in evaluation of this patient?

Quizplus · Accepted Answer

11ec25c8_d6de_9118_bc81_27d52ee8a4de_MD0003_00 This patient has an ectopic urethral meatus consistent with hypospadias. During embryologic development, androgens stimulate fusion of the urethral folds; incomplete or partial fusion results in hypospadias. The degree of fusion determines the location of the urethral meatus, and in severe cases the urethral opening is located on the perineum or scrotum. Patients with severe hypospadias may also have an underdeveloped penis with a small glans and/or severe penile curvature (chordee). hypospadias In some cases, severe hypospadias can be indicative of a disorder of sex development (eg, androgen receptor mutation). About 10% of hypospadias cases are associated with cryptorchidism (undescended testis), and the condition may represent either virilization of a genotypic female (XX) or undervirilization of a genotypic male (XY). Therefore, the first step in evaluation is karyotype analysis. Even if testes are present (indicating the presence of at least some functional Y chromosome), a karyotype is still needed in severe hypospadias to evaluate for mosaicism. Pelvic ultrasound may also be indicated to assess for internal genitalia (eg, uterus). (Choice A) Echocardiography is useful in the identification of heart disease (eg, congenital heart disease, heart failure). However, this patient's faint (eg, I/VI) murmur is characteristic of a pulmonary flow murmur of newborn, which is benign. In addition, acrocyanosis (cyanosis of digits and around the mouth) is a normal newborn finding due to peripheral vasoconstriction. (Choice B) Screening head ultrasound is often performed in premature neonates due to increased risk of intraventricular hemorrhage, which is rare in full-term neonates. In addition, this patient's examination is normal, including the presence of overlapping sutures (ie, temporary overriding of skull bones caused by passage through birth canal). (Choice D) Liver ultrasound is indicated for hepatomegaly (liver edge >3.5 cm in neonates), which can be suggestive of cholestasis or congestive heart failure. This patient's liver is 2 cm below the costal margin, which is normal. (Choice E) Prenatal screening for neural tube defects (NTDs) includes a maternal serum alpha-fetoprotein (AFP). However, ultrasound (not AFP) is performed in the newborn with findings concerning for NTDs (eg, deep/large sacral dimple without a base). A sacral dimple with intact skin, as in this patient, is a benign finding that does not require further workup. Educational objective: Severe hypospadias is characterized by a urethral meatus located at the perineum or scrotum, an underdeveloped penis/glans, and severe penile curvature. This condition may be indicative of a disorder of sex development and warrants karyotype analysis and pelvic ultrasound. References: Current hypospadias management: diagnosis, surgical management, and long-term patient-centered outcomes. (http://www.ncbi.nlm.nih.gov/pubmed/28265319)

A Term Newborn Is Evaluated in the Nursery 1 Hour