A 28-week premature male infant is admitted to the neonatal intensive care unit (NICU) immediately after birth. The infant initially required positive pressure ventilation due to respiratory distress but is now on nasal continuous positive airway pressure (nCPAP). On day 3 of life, the NICU team notes increasing apnea episodes, hypotonia, and a sudden drop in hematocrit levels. A cranial ultrasound is performed. Which of the following is the most likely location of the hemorrhage in this infant?

A 28-year-old woman presents to the obstetrics clinic with a complaint of vaginal bleeding at 12 weeks of gestation. She reports that the bleeding started a few days ago and is intermittent, with no associated pain. She has had no prior complications in this pregnancy and no significant medical history. Her prenatal labs, including beta-hCG levels, were initially normal but have been rising more rapidly than expected for gestational age. On physical examination, her uterus is larger than expected for 12 weeks, and there is no fetal heart tone detected on Doppler. An ultrasound is performed, which reveals a thickened placenta with multiple cystic spaces, often described as a “Swiss cheese” or “honeycomb” appearance. Additionally, the ultrasound identifies a malformed fetus with abnormalities such as growth restriction or structural defects. Which of the following is the most likely diagnosis?

A 5-week-old male infant is brought to the pediatric clinic with complaints of projectile, non-bilious vomiting after every feed for the past 7 days. The parents report that the baby is always hungry after vomiting and feeds vigorously. Physical examination reveals a palpable olive-shaped mass in the right upper quadrant and visible peristaltic waves across the abdomen. An abdominal ultrasound is performed. Which of the following ultrasound findings is most characteristic of infantile hypertrophic pyloric stenosis (IHPS)?

A 3-week-old male infant is brought to the pediatrician by his parents for projectile vomiting after every feed for the past 5 days. The vomitus is non-bilious, and the infant appears hungry after each episode. On examination, the baby has dry mucous membranes, visible peristaltic waves, and a palpable olive-shaped mass in the right upper quadrant. Upon further history, the parents reveal that the infant was treated with erythromycin for pertussis prophylaxis in the first week of life. Which of the following statements regarding macrolide exposure and infantile hypertrophic pyloric stenosis (IHPS) is correct?

A 4-week-old male infant, firstborn to a healthy 25-year-old mother, is brought to the pediatric clinic with complaints of progressive vomiting over the past week. The parents report that the baby has been spitting up after feeds for two weeks, but in the last three days, the vomiting has become projectile and occurs after every feed. The vomitus is non-bilious and contains milk. The infant is exclusively breastfed. The parents also note that the baby seems hungry and feeds vigorously after vomiting. They are concerned because he appears less active and has not gained weight as expected. The mother denies fever, diarrhea, or respiratory symptoms. Examination General appearance: Thin, lethargic infant with dry mucous membranes and sunken fontanelle, suggesting dehydration. Vital signs: Heart rate: 150 bpm (mild tachycardia). Respiratory rate: 45 breaths/min. Temperature: 98.6°F (37°C). Abdominal exam: Visible peristaltic waves moving from left to right across the abdomen after feeding. A firm, olive-shaped mass is palpable in the right upper quadrant. No tenderness or distension. Growth parameters: Weight below the 10th percentile for age. Workup: Laboratory findings: Serum chloride: 96 mEq/L (low). Serum potassium: 3.0 mEq/L (low). Serum bicarbonate: 30 mEq/L (elevated). Suggests hypochloremic metabolic alkalosis.What is the most appropriate diagnostic test for this condition?

A 34-year-old woman, gravida 3 para 2, presents to the labor and delivery unit at 39 weeks of gestation in active labor. Her pregnancy has been complicated by mild polyhydramnios diagnosed at 32 weeks, but she has otherwise been healthy. She undergoes an uneventful induction of labor. However, during the second stage of labor, she suddenly becomes cyanotic and complains of severe shortness of breath. Within minutes, she loses consciousness and exhibits signs of cardiovascular collapse, including hypotension and tachycardia. The labor and delivery team initiates immediate resuscitative measures, including oxygen supplementation and intravenous fluid boluses. Despite these interventions, her blood pressure continues to drop, and she requires intubation for respiratory support. The fetal heart monitor shows bradycardia. Amniotic fluid embolism is suspected and an emergency cesarean section is performed within 15 minutes. The infant is delivered with an initial Apgar score of 2 but responds well to resuscitation and is transferred to the neonatal intensive care unit for further monitoring. Meanwhile, the mother develops significant vaginal bleeding during surgery, requiring rapid transfusion of blood products. Laboratory results reveal evidence of disseminated intravascular coagulation (DIC). Which laboratory finding is most consistent with disseminated intravascular coagulation (DIC) in amniotic fluid embolism?