A 1-week-old girl is evaluated in the neonatal intensive care unit. She was born at 29 weeks gestation via spontaneous vaginal delivery due to preterm labor. Her mother had routine prenatal care. Rupture of membranes with clear amniotic fluid occurred 2 hours prior to delivery. Apgar scores were 8 and 8 at 1 and 5 minutes, respectively. Birth weight was 1.51 kg (3 lb 5.3 oz). The patient has been tolerating enteral feeds via an orogastric tube, and her weight remains appropriate. Vital signs are normal. Examination shows a sleeping, nondysmorphic infant. A nasal continuous positive airway pressure mask is in place. The anterior fontanelle is open and soft. The oropharynx is clear, and the neck is supple. The lungs are clear to auscultation, and cardiac examination is unremarkable. The abdomen is soft without organomegaly. The external genitalia appear normal, and the skin is intact. The newborn moves all 4 extremities. Which of the following screening tests is indicated in this patient?
Intraventricular hemorrhage | |
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*Performed if symptomatic or as routine screening if <32 weeks gestational age. | |
Prematurity is the greatest risk factor for intraventricular hemorrhage (IVH), which results from ruptured germinal matrix vessels. The germinal matrix is a highly vascularized, fragile part of the brain in the periventricular area that gives rise to neurons and glial cells during fetal development. Premature neonates lack supportive structures around the germinal matrix, making its thin-walled capillaries prone to rupture, particularly with changes in cerebral perfusion (eg, hypoxia). Risk of IVH inversely correlates with gestational age, and neonates born at <32 weeks gestation are at highest risk because the germinal matrix involutes by week 32.
IVH typically occurs in the first 3-4 days of life; symptoms may include a bulging fontanel, anemia, apnea, and seizures. However, up to 50% of IVH cases are asymptomatic. Therefore, all preterm neonates born at <32 weeks gestation should undergo screening head ultrasound at age 1-2 weeks. Ultrasound is ideal because it does not use radiation and is highly sensitive for detecting blood (seen as echogenicity) in the germinal matrix and/or ventricles.
Although treatment of IVH is mostly symptomatic (eg, blood pressure stabilization, antiseizure medication), early detection and monitoring is important to promptly treat complications (eg, posthemorrhagic ventricular dilation).
(Choice A) Preterm newborns are at increased risk of necrotizing enterocolitis (NEC), which can present with gastrointestinal (eg, feeding intolerance, abdominal distension) or systemic (eg, apnea, temperature instability) symptoms. Although abdominal imaging helps detect NEC in symptomatic patients, screening ultrasound is not recommended.
(Choice B) Although prematurity (particularly gestational age <28 weeks) increases the risk of a patent ductus arteriosus, a continuous, machine-like murmur would be expected with this condition. Echocardiogram is not performed as routine screening.
(Choice D) Karyotype analysis to identify a chromosomal disorder is indicated in some patients with dysmorphic features (eg, upslanting palpebral fissures and epicanthal folds in Down syndrome). This patient does not have dysmorphic features, and karyotyping is not performed as routine screening in premature newborns.
(Choice E) Premature neonates are at increased risk of sepsis, and evaluation (eg, cultures, complete blood count, urinalysis) is performed if signs of infection (eg, temperature instability, apnea) are present. This patient's vital signs are normal, and screening urinalysis is not indicated in newborns regardless of gestational age.
Educational objective:
Preterm newborns are at increased risk of developing intraventricular hemorrhage (IVH) due to the presence of the germinal matrix, a fragile, highly vascularized area in the brain. Because IVH can be asymptomatic, all preterm neonates born at <32 weeks gestation require screening head ultrasound.