When a Missed Shoulder Injury at Birth Shows Up as Popping Weeks Later

A newborn is supposed to leave the hospital with a documented physical exam confirming that its shoulders, arms, and collarbones look and move the way they should.

So when parents notice a clicking or popping sound weeks after a seemingly normal discharge, a fair question follows: was this actually there all along, and should the hospital have caught it?

Some birth-related shoulder injuries are genuinely difficult to detect at the standard newborn exam, even when that exam is done correctly. Others are the kind of finding a proper exam is specifically designed to catch.

This article focuses on, what the newborn discharge exam is actually supposed to check and when a delayed diagnosis is a pattern worth having reviewed.

What the Newborn Discharge Exam Is Supposed to Check

Before a newborn leaves the hospital, the standard physical exam includes a specific musculoskeletal and neurologic check relevant to shoulder and arm injuries.

That includes observing spontaneous movement in all four limbs, checking the Moro reflex (the startle response where a newborn’s arms extend and then come back to the midline), and palpating both clavicles for tenderness, deformity, or crepitus, a crackling sensation that can indicate a fracture.

An asymmetric Moro reflex, where one arm moves less than the other, is the classic textbook sign of a brachial plexus injury, and it’s something the exam is specifically designed to pick up in the first 24 hours.

For the broader question of what a shoulder popping sound generally means and when it’s likely benign, our overview of newborn shoulder popping covers that ground in more depth.

Why Clavicle Fractures Are Often Missed at First

Clavicle fractures don’t always follow the same detection pattern as nerve injuries. A 10-year study of over 77,000 births published in Pediatrics International found that while 86.2 percent of clavicle fractures were detected before discharge, 13.8 percent were not identified until a follow-up visit after the baby had already gone home.

That gap exists because a subtle, non-displaced fracture often produces no visible sign at the time of the exam, no swelling, no obvious deformity, and only becomes apparent later, whether through a small bump, decreased arm movement, or a clicking or popping sensation a parent notices weeks in.

That pattern, by itself, is not a sign anything was missed through negligence. It’s a documented feature of how this specific injury can present.

Why Brachial Plexus Injuries Are a Different Story

Brachial plexus injuries generally don’t follow the same quiet timeline. Because the injury affects nerve function rather than bone healing, the classic sign, an asymmetric Moro reflex or reduced spontaneous arm movement, is typically present from birth and is exactly what the newborn exam is designed to catch in the first 24 hours.

This is an important distinction: if your baby’s discharge exam documented a normal, symmetric Moro reflex and full arm movement, but weeks later you’re seeing consistent arm weakness, limited movement, or a weak grasp on one side, alongside any popping sound, that’s a meaningfully different pattern than a delayed clavicle finding.

Our guide on signs that a baby’s arm weakness may point to Erb’s palsy or nerve injury explains what that kind of presentation typically looks like and what to do next.

If a clavicle fracture is the more specific concern instead, our breakdown of what it means when a baby’s collarbone breaks during birth covers healing timeline and treatment in more detail.

What a Genuinely Missed Diagnosis Looks Like

Given how differently these two injuries present, “missed diagnosis” means something different for each one. For a clavicle fracture, a delayed finding usually isn’t a missed diagnosis at all, it’s the expected course for a subtle, non-displaced fracture.

What would actually be concerning is a documented finding at birth, such as noted crepitus, tenderness, or an observed difficult delivery with shoulder dystocia, that was never followed up with an X-ray or a documented referral.

Our resource on negligent traction causing a total brachial plexus injury explains how the delivery mechanics themselves, not just the post-birth exam, factor into this kind of review.

What to Do If You’re Noticing This Weeks After Discharge

If you’re hearing a popping sound along with any arm weakness, limited movement, visible swelling, or a bump near the collarbone, start with your pediatrician rather than trying to sort out the cause yourself.

An exam, and an X-ray if a fracture is suspected, will typically settle the question quickly. If you also have concerns about the delivery itself, whether it was described as difficult, involved instruments, or included shoulder dystocia, it’s reasonable to request the complete delivery and newborn exam records rather than relying on memory.

Those records will show exactly what was checked, what was documented as normal, and whether any follow-up was recommended, which is the actual basis for evaluating whether anything was missed.

New York also places specific time limits on medical malpractice claims, and those limits don’t pause indefinitely just because the patient was a newborn.

Our detailed breakdown of New York’s birth injury statute of limitations and infancy tolling rules explains how that calculation actually works, which is worth understanding early if you have real concerns rather than after time has passed.

Frequently Asked Questions

If my baby’s clavicle fracture wasn’t found until weeks after birth, does that mean the hospital missed it

Not necessarily. Research on this specific injury shows that a meaningful share of clavicle fractures, roughly 1 in 7 in one large study, aren’t identified until after discharge, because the most reliable early sign is a small area of healing callus that often isn’t detectable for 7 to 10 days. A delayed clavicle finding by itself is a documented, expected pattern for this injury rather than evidence of a missed exam.

Why would a brachial plexus injury be different from a clavicle fracture in terms of timing

A brachial plexus injury affects nerve function, so its hallmark sign, reduced or asymmetric arm movement, is typically present immediately and is specifically what the newborn exam’s Moro reflex check is designed to catch. That’s different from a clavicle fracture, where the bone itself may show no detectable signs until healing produces a palpable callus days later. This is why the same “popping weeks later” symptom means something different depending on which injury is actually involved.

What should I ask for if I want to check whether the discharge exam was done properly

Request the complete newborn physical exam documentation, not just the discharge summary, including the specific findings for the Moro reflex, clavicle palpation, and arm movement in each limb. If your delivery involved shoulder dystocia, forceps, or vacuum assistance, also ask whether that was documented and whether any follow-up was recommended based on it.

Does a normal discharge exam rule out a birth-related shoulder injury

No, and that’s specifically true for non-displaced clavicle fractures, which can be genuinely undetectable at the time of a properly performed exam. A normal discharge exam is meaningful evidence that nothing was clinically apparent at that moment, but it doesn’t rule out an injury that simply hadn’t become detectable yet.

How is a legal review of a delayed diagnosis different from just asking my pediatrician about it

Your pediatrician can tell you what’s happening with your baby’s shoulder or arm right now and what treatment is appropriate. A legal review looks backward at the delivery and newborn exam records specifically to determine whether something that should have been caught or documented at the time was missed, which is a different question that generally requires comparing the actual record against what standard practice calls for.

Getting Clarity Instead of Guessing

A popping sound that shows up weeks after a normal-seeming discharge can mean several very different things, and the timeline itself is actually useful information rather than just a source of worry.

Understanding which injuries are expected to surface late, and which ones should have shown up immediately, gives you a real way to judge whether your baby’s care simply followed the ordinary course of a common, benign injury, or whether something in the record is worth a closer look.

This article is for informational and educational purposes only. It is not a substitute for medical advice from your child’s healthcare providers or legal advice based on your family’s specific circumstances.

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