16.2 Growth, Developmental Delay, and Sensory Impairment

16.2 Growth, Developmental Delay, and Sensory Impairment

Quick Answer: IUGR is restricted growth before birth; postnatal failure to thrive is inadequate growth after birth. Developmental care protects sleep, reduces toxic sensory load, and uses corrected age for preterm milestones. Screen ROP in infants ≤1500 g or ≤30 weeks (plus selected unstable larger infants). Treat congenital glaucoma as an ophthalmic emergency (tearing plus photophobia plus cloudy or enlarged cornea). Use AABR in the NICU, follow 1-3-6 hearing timelines, complete CCHD and metabolic screens, and observe preterm infants in a car safety seat before discharge.

Two Multisystem leaves live together here because the same former 24-week infant can leave the NICU with a growth chart that is still climbing, a pending ROP visit, a refer on hearing, and a family who has never practiced a car-seat installation. The CCRN Neonatal exam will ask you to choose the next safe action, not to quote an ophthalmology atlas.

IUGR is not the same as failure to thrive

Small for gestational age (SGA) means birth weight below the 10th percentile for gestational age. It is a plot on a curve, not a diagnosis. Intrauterine growth restriction (IUGR) means the fetus did not grow along its expected path, usually because of placental insufficiency, maternal hypertension, smoking, infection, or a fetal genetic or anomalous problem. Symmetric IUGR (head, length, and weight all small) often reflects an early, global insult. Asymmetric IUGR (weight lagged, head relatively spared) often reflects later placental failure. Not every SGA infant is IUGR, and an IUGR infant delivered before the weight crossed the 10th percentile can still be appropriate for gestational age on the first plot.

Postnatal failure to thrive starts after birth: the infant crosses major percentiles downward, fails to regain birth weight in a reasonable window, or cannot meet the gram-per-day gain expected for postmenstrual age. Causes split cleanly for exam purposes:

• Not enough going in: unsuccessful latch, restricted volumes, chaotic mixing of formula, social neglect
• Not staying in: vomiting, diarrhea, high ostomy losses after NEC surgery
• Not absorbing: short bowel, cholestasis, cow's-milk protein enteropathy, cystic fibrosis
• Burning too much: chronic lung disease, congenital heart disease, hyperthyroidism, hypothermia from inadequate wrapping

A former IUGR infant can later fail to thrive if you discharge on 22 kcal formula and the family cannot obtain it. Conversely, a well-grown term infant can fail to thrive from insufficient intake with no prenatal story at all. Plot weight, length, and head on the same gestational-age-appropriate chart (Fenton in preterm life, WHO after term-equivalent) and use z-scores when the curve is hard to eyeball. Many growing preterm infants need roughly 110–150 kcal/kg/day and adequate protein to catch up; the number is a starting range, not a religion. If head circumference lags while weight soars, think about the brain (or fluid), not just calories.

Developmental delay and developmental care

Corrected age (chronologic age minus weeks born early) is how you interpret motor and social milestones in preterms, typically through 24 months and sometimes to 36 months depending on the tool. A 6-month-old born at 28 weeks is 3 months corrected: if that infant is just finding hands, that is not the same as a term 6-month-old who cannot sit. True delay is persistent lag after correction, plus red flags such as fisting, absent visual tracking, or a falling head-circumference percentile.

The NICU can cause delay as well as reveal it. Loud alarms, 24-hour lighting, clustered painful procedures, and underused skin-to-skin time add up. Developmental care is the counter-strategy: cluster handling so sleep is protected, shade the eyes, keep conversation and radio noise down (many units aim near 45 dB), offer nonnutritive sucking during gavage, use two-person cares for the smallest infants, and put stable infants skin-to-skin. State regulation—moving from deep sleep to a robust crying peak without crashing saturations—is a neurologic skill you train, not a personality trait. Document what the infant tolerates. Follow-up clinics, early-intervention referrals, and honest talk about risk after severe IVH, PVL, or prolonged ventilation belong in the discharge plan, not as an afterthought.

ROP: who, when, and what the stages mean

Retinopathy of prematurity (ROP) is disordered growth of retinal vessels in an incompletely vascularized eye. The more posterior the avascular retina (Zone I is the worst), the more dangerous the disease. Oxygen is a risk factor, but so are extreme prematurity, poor weight gain, fluctuation of saturations, sepsis, and transfusion. Screening exists because untreated proliferative disease can pull the retina off and blind the infant, and because treatment (laser and/or anti-VEGF) works only if someone looks on time.

U.S. programs screen:

• Birth weight ≤1500 g, or
• Gestational age ≤30 weeks, or
• Selected infants 1500–2000 g or >30 weeks whose course was unstable (inotropes, prolonged oxygen, unmonitored oxygen)

The first exam is timed by postmenstrual age, not by convenience: the most immature infants are often first examined near 31 weeks PMA; infants born at 30 weeks are often first examined near 34 weeks PMA (about 4 weeks of life). One fully vascularized exam can stop screening. Anything short of that needs a scheduled follow-up that survives discharge. Canceling an ROP exam because the baby is going home today is a classic preventable-harm item.

Plus disease (dilated veins, tortuous arteries in the posterior pole) and aggressive posterior ROP escalate urgency even if the stage number still looks modest. Dilating drops can cause apnea, bradycardia, and delayed gastric emptying; monitor around exams. You are not expected to laser an eye on the test, but you are expected to know that missed follow-up, not missed trivia about Stage 2, is how blindness happens.

Congenital glaucoma versus ordinary tearing

Primary congenital glaucoma is trabecular dysgenesis with high intraocular pressure. The classic triad is epiphora (tearing), photophobia, and blepharospasm. Add cloudy or enlarged corneas (buphthalmos), an enlarged horizontal corneal diameter (a term newborn cornea is typically near 9.5–10.5 mm; enlargement is concerning), and Haab striae. This is not nasolacrimal duct obstruction, which tears with a clear cornea and no light aversion. Urgent pediatric ophthalmology, often an exam under anesthesia, and surgical angle surgery are the path. Bedside nurses trigger that path by refusing to file tearing under normal baby when the eye looks large or hazy.

Congenital hearing impairment

Congenital hearing loss may be genetic (including connexin 26), infectious (CMV is the leading nongenetic congenital cause), or acquired in the NICU from hypoxia, hyperbilirubinemia at exchange levels, meningitis, ECMO, or ototoxic drugs (aminoglycosides, loop diuretics). Joint Committee on Infant Hearing (JCIH) programs still teach 1-3-6: screen by 1 month, diagnose by 3 months, start intervention by 6 months. High-performing programs may aspire to 1-2-3. In the NICU, screen with automated auditory brainstem response (AABR), not otoacoustic emissions alone, because OAE can miss auditory neuropathy. A refer is not a diagnosis; it is a ticket to diagnostic ABR. Failed screens should prompt consideration of CMV testing per local protocol. Parental concern about hearing after a pass still deserves a referral. Language access for the family (including American Sign Language resources when chosen) is part of facilitation of learning; the professional-caring chapters cover the broader skill.

Testable general screening actions

Before a high-risk neonate leaves your unit, several screens are not optional paperwork:

1. CCHD pulse oximetry. Current AAP-endorsed technique screens a well-appearing infant at ≥24 hours (or immediately before an earlier discharge). Measure the right hand and a foot. A pass requires both saturations ≥95 percent in the current algorithm, with only one retest for an indeterminate result (tighter than the older two-retest rule). A fail is a medical evaluation, not a repeat tomorrow after you ignore the number. Pulse oximetry does not catch every lesion; coarctation can still sneak through.
2. Hearing as above; do not discharge a refer without a booked diagnostic visit.
3. Metabolic / RUSP heel-stick. Timing is usually after 24 hours of protein feeding when possible. NICU infants often need an admission specimen plus later specimens because TPN, transfusions, and early collection distort results. The nurse's job is the right time, the right circles, and a system that actually reports out-of-range amino acids at 2 a.m.
4. Car-seat observation for infants born at <37 weeks, and for selected hypotonic or micrognathic infants. Observe in the family's own seat, correctly reclined, for 90–120 minutes (or the ride home if longer). Failure is apnea, bradycardia, or desaturation that your unit has defined (commonly saturation below 90 percent or a pause that is not a life-sustaining pattern). Failure means a car bed, a delay, or a repeat test—not a shrug and a discharge at midnight.

Worked scenario

A 27-week infant is 38 weeks PMA, on full oral feeds, with an ROP exam yesterday showing Zone II, Stage 1, no plus, and a 1-week follow-up. Hearing was a refer on AABR. CCHD saturations were 97 percent and 96 percent. The car-seat study showed two desaturations to 82 percent with a 12-second pause. The discharge-blocking actions are the car-seat failure and the unsigned ROP and audiology appointments—not starting a new calorie concentration because the weight is tracking along the 10th percentile. Growth is a long game; an unsafe ride home is today's harm.

Exam traps

• Using IUGR and failure to thrive as synonyms
• Screening only infants under 1000 g for ROP
• Treating tearing as dacryostenosis when the cornea is cloudy
• Using OAE-only protocols in the NICU
• Skipping the car-seat observation because the infant is a late preterm who never needed a ventilator