3.3 Common Newborn Problems, Birth Injury & Screening

Newborn Screening Programs

Universal newborn screening exists because several conditions are silent at birth but cause irreversible harm if treatment is delayed, and can be detected and treated cheaply before symptoms appear.

Metabolic and genetic screening

A dried blood spot (heel-prick) sample is collected, ideally 24-48 hours after birth and after the infant has had adequate protein feeding — testing too early risks a false-negative for conditions like phenylketonuria (PKU), since the abnormal metabolite needs time to accumulate once protein intake begins. Panels vary by country but commonly include congenital hypothyroidism, PKU, galactosemia, congenital adrenal hyperplasia (CAH), hemoglobinopathies such as sickle cell disease, cystic fibrosis, and inborn errors of fatty-acid oxidation such as MCAD deficiency.

Exam trap: untreated congenital hypothyroidism is one of the most preventable causes of intellectual disability worldwide. The infant is often clinically normal-appearing at birth because some maternal thyroxine crosses the placenta — which is precisely why screening, rather than waiting for clinical signs, is essential.

Hearing screening

Universal newborn hearing screening uses otoacoustic emissions (OAE) and/or automated auditory brainstem response (AABR) before discharge. The accepted benchmark is the 1-3-6 rule: screen by 1 month of age, complete diagnostic audiology by 3 months, and begin intervention by 6 months. Risk factors prompting closer follow-up include a NICU stay longer than 5 days, ototoxic medication exposure, a family history of childhood hearing loss, craniofacial anomalies, and congenital CMV infection.

Critical congenital heart disease (CCHD) screening

Pulse oximetry is measured in the right hand and one foot at 24-48 hours of age. A saturation below 90% in either limb is an immediate fail. A saturation of 90-94%, or a difference of more than 3% between the right hand and the foot, triggers a repeat screen an hour later before the result is classified as pass or fail. This screen targets duct-dependent lesions that may appear well until the ductus arteriosus closes.

Hip screening for developmental dysplasia of the hip (DDH)

Clinical exam uses the Ortolani maneuver (reduces a dislocated hip) and the Barlow maneuver (dislocates an unstable hip) at every well-child visit in early infancy. Risk factors warranting a screening hip ultrasound at around 6 weeks regardless of exam findings include breech presentation, female sex, family history, firstborn status, and oligohydramnios.

Vitamin K prophylaxis

Newborns have low vitamin K stores and minimal gut bacterial synthesis in the first days of life, placing them at risk for vitamin K deficiency bleeding (VKDB). VKDB is classified as early (within 24 hours — often linked to maternal medications such as anticonvulsants or warfarin), classic (days 1-7), or late (weeks 2-12; exclusively breastfed infants without prophylaxis carry the highest risk). A single intramuscular vitamin K dose at birth (typically 1 mg for term infants and 0.3-0.5 mg for low-birth-weight or preterm infants per local protocol) is standard prophylaxis and is far more reliable than oral regimens for preventing late VKDB. Presentation includes GI bleeding, ecchymoses, or intracranial hemorrhage with a prolonged PT and normal platelet count — a coagulation pattern that can mimic abusive head trauma on imaging. Parents who decline vitamin K should be counseled on the risk of catastrophic late hemorrhage.

Birth Injuries

Brachial plexus palsy

Risk factors for either type: shoulder dystocia, fetal macrosomia, and difficult forceps- or vacuum-assisted delivery. Most brachial plexus injuries resolve spontaneously within weeks to a few months with physical therapy; refer for surgical evaluation if there is no recovery by 3-6 months.

Clavicle fracture

The most common birth fracture, associated with macrosomia and shoulder dystocia. It presents with decreased spontaneous arm movement (pseudoparalysis), crepitus over the clavicle, and an asymmetric Moro reflex. A palpable callus at 7-10 days confirms healing. Treatment is supportive, and the prognosis is excellent.

Scalp and head injuries — a classic differentiation

Common Benign Findings vs. Red Flags

Benign, reassuring findings that should be explained to parents rather than treated: erythema toxicum neonatorum (eosinophilic pustules on an erythematous base, resolving spontaneously), Mongolian spots (dermal melanocytosis, more common with darker skin tones), milia, Epstein pearls (palatal cysts), breast engorgement or witch's milk, neonatal vaginal discharge or pseudomenses from maternal hormone withdrawal, and physiologic jaundice appearing after 24 hours and peaking on day 3-5.

Red flags requiring urgent evaluation: jaundice appearing within the first 24 hours of life is always pathologic and suggests hemolysis; bilious vomiting should be treated as bowel malrotation with volvulus until proven otherwise; failure to pass meconium within 48 hours raises concern for Hirschsprung disease; and an absent red reflex suggests congenital cataract or retinoblastoma.

Feeding Problems in the Well Newborn

Ineffective latch or intake is common and usually correctable, but the exam expects recognition of specific thresholds for concern: weight loss greater than 7% of birth weight should prompt a feeding evaluation, and loss greater than 10% requires medical work-up. Reassuring signs of adequate intake include 6 or more wet diapers per day by day 5-6 and a return to birth weight by 2 weeks of age. Two jaundice patterns related to feeding are commonly confused on exams:

• Breastfeeding (lack-of-intake) jaundice — appears in the first week of life from insufficient milk intake and reduced stooling; managed by improving feeding technique and frequency
• Breast milk jaundice — appears after the first week, caused by a factor in breast milk that inhibits bilirubin conjugation, can persist for weeks in an otherwise thriving infant, and does not require stopping breastfeeding.