When to Call Pediatrician - Newborn Warning Signs

 Published - February 6 Last Updated: February 6, 2026

At 3 a.m. on day ten, my son felt warm. I grabbed the thermometer while shaking hands. It read 100.5°F. I called the after-hours line, barely breathing. "Take him to the emergency room immediately,” the nurse instructed with composure. 

Fever in newborns under three months is never wait-and-see. Four hours and many tests later, he was fine—just a virus his body could handle. But I'll never regret that ER visit. Here's when to call pediatrician immediately versus when you can breathe and wait.

Knowing when to call pediatrician is crucial—explore our complete newborn health guide for all aspects of baby health and care alongside this emergency reference guide.

Call 911 Immediately For:

Some situations don't wait for a phone call to the doctor. These need emergency services now.

Difficulty Breathing or Turning Blue

Call 911 if the baby -

• Has blue or gray lips, tongue, or skin
• Is gasping for air or struggling to breathe
• Has severe chest retractions (skin pulling in deeply between ribs)
• Makes grunting sounds with every breath
• Goes limp or loses consciousness

Note - Babies normally breathe faster than adults (30-60 breaths per minute). Periodic pauses under 10 seconds are also normal. But blue colouring or obvious distress is always an emergency.

Unresponsive or Extremely Lethargic

Call 911 if the baby -

• Won't wake up even with stimulation
• Is completely floppy (no muscle tone)
• Shows no response to touch, sound, or light
• Has no alert periods at all

This differs from a deeply sleeping baby who can be roused. This is a baby who cannot be woken.

Seizure Activity

Call 911 if the baby has -

• Rhythmic jerking movements, they can't be stopped from
• Stiffening of the body with eyes rolling back
• Uncontrollable shaking
• Loss of consciousness with convulsions

Not a seizure - Normal newborn startles (Moro reflex) or the twitchy movements during sleep. Seizures involve the entire body and cannot be stopped by holding the baby still.

Severe Bleeding

Call 911 if -

• Bleeding won't stop with direct pressure after 10 minutes
• Blood is spurting
• A large amount of blood loss
• Bleeding from the umbilical cord that soaks through multiple diapers

For detailed information on specific emergencies, read our comprehensive illness symptom guide.

Call Pediatrician Right Away (Within the Hour)

These situations require a same-day medical evaluation but aren't necessarily 911 calls. This is when to call pediatrician without delay.

Fever in Newborn (Under 3 Months)

Rectal temperature of 100.4°F (38°C) or higher in a baby under 3 months old requires immediate ER evaluation. Don't wait until morning. Don't try to bring it down first. Go to the ER.

Why this is serious - Newborn immune systems can't localize infections well. A fever could indicate a serious infection (meningitis, sepsis, urinary tract infection) that needs immediate treatment. Babies and young people who have fevers typically get admitted for observation and IV antibiotics while waiting for test results.

Persistent Vomiting

Call immediately if -

• Vomiting is forceful or projectile (shoots across the room)
• Baby vomits after every feeding for 6+ hours
• Vomit contains blood (red or coffee-ground appearance)
• Vomit is green or yellow (bile)

Learn about distinguishing reflux from seriousvomiting—projectile vomiting and bloody vomit always warrant immediate calls.

Normal spit-up - Dribbles out, happens occasionally, baby seems fine. Concerning vomiting - Forceful, frequent, the baby seems unwell.

Signs of Dehydration

Call if the baby shows multiple signs -

• After the fifth day, we had fewer than six wet diapers within 24 hours.
• Dark yellow or orange urine
• Sunken soft spot (fontanelle) on the head
• Dry mouth and lips
• No tears when crying
• Lethargic and weak
• Sunken eyes

Monitoring diaper output helps catch dehydration early. Fewer than 6 wet diapers after day 5 needs evaluation immediately.

Crying inconsolably (3+ Hours)

If the baby has been crying inconsolably for 3+ hours straight and nothing soothes them, call. This could indicate -

• Severe gas or constipation
• Intussusception (bowel obstruction)
• Hernia that's stuck
• Infection causing pain

Colic involves crying but typically has breaks, and the baby can sometimes be soothed temporarily. True inconsolable crying with no breaks at all for hours needs evaluation.

Blood in Stool or Vomit

Call same day for -

• Bright red blood in stool
• Blood in vomit (even small amounts)
• Black, tarry stool (after meconium has passed)

Small streaks of blood in stool can be from a tiny anal fissure or milk protein sensitivity—still worth a call, but less urgent.

Yellow skin or eyes, especially after the first week, may indicate jaundice warning signs requiring bilirubin testing.

Call During Office Hours

These can wait for normal office hours, but still deserve a conversation with your pediatrician. This is still when to call pediatrician, just not urgently.

Schedule a same-day or next-day appointment for -

• Mild rash that's spreading
• Constipation (no stool in 3+ days with signs of discomfort)
• Persistent congestion affecting feeding or sleep
• Eye discharge (possible blocked tear duct)
• Mild jaundice appearing after day 3-5
• Questions about feeding or development

If you're concerned about inadequate weight gain or feeding efficiency, schedule a weight check with your pediatrician.

These issues matter, but they don't require middle-of-the-night calls or ER visits. Use your pediatrician's online portal or call first thing in the morning.

Temperature Taking and Fever

Understanding fever is critical to knowing when to call pediatrician immediately.

How to Take Temperature

For babies under 3 months, rectal temperature is most accurate.

How to take rectal temp -

1.    Use a digital thermometer with a flexible tip

2.    Apply petroleum jelly to the tip

3.    Lay baby on back, hold legs up gently

4.    Insert the thermometer ½ to 1 inch into the rectum

5.    Hold still until thermometer beeps

6.    Remove and read

Armpit (axillary) temperature - Less accurate but easier. Add 1 degree to get the approximate rectal equivalent. If axillary reads 99.4°F or higher, take a rectal temp to confirm.

Never use: Ear thermometers (inaccurate under 6 months), forehead strips, or pacifier thermometers for important readings.

What Counts as Fever

Fever = 100.4°F (38°C) or higher (rectal)

Normal temperature: 97.5-100.3°F

Under 3 months: Any fever 100.4°F or higher = ER immediately

Over 3 months: Fever alone isn't as concerning, but combined with other symptoms (lethargy, refusing to eat, extreme fussiness), call the same day.

Recognizing Dehydration

Knowing the signs helps you catch dehydration before it becomes serious—another key aspect of when to call pediatrician urgently.

Check for -

• Wet diapers - Fewer than 6 per day after day 5 is concerning
• Fontanelle - Soft spot on top of head—should be flat or slightly curved in. If sunken, the baby is dehydrated.
• Skin turgor - Gently pinch skin on the belly. Should spring back immediately. If it stays "tented," dehydration is present.
• Mucous membranes - The mouth and lips should be moist. Dry = dehydrated.
• Behaviour - Lethargic, weak, not responding normally

Breathing Concerns

Normal vs. Abnormal Breathing

Normal newborn breathing -

• 30-60 breaths per minute
• Occasional pauses under 10 seconds
• Slight chest movement
• Muted or soft sounds

Call immediately if breathing shows -

• Blue or gray colour anywhere
• Severe retractions (skin pulling in deeply between ribs)
• Flaring nostrils with every breath
• Grunting sounds
• Gasping
• Breathing over 60 breaths per minute consistently

A stuffy nose alone isn't an emergency. Babies are nose breathers and often sound congested. As long as the baby can eat, sleep, and breathe without distress, congestion can wait for office hours.

Using After-Hours Resources

Figuring out when to call pediatrician after hours doesn't mean you're alone.

After-hours nurse lines - Most pediatric offices have an answering service that connects you with an on-call nurse or doctor. They triage your concern and advise whether to go to the ER, come in first thing, or monitor at home.

Call the regular office number even after hours—it will route to the service.

Telemedicine: Many insurance plans now cover virtual urgent care visits. A doctor can see the baby via video and determine the next steps. Successful for "should I be worried about this rash" type questions.

Urgent care vs. ER -

• Urgent care - Minor illnesses, minor injuries, non-emergency concerns outside office hours
• ER - True emergencies, babies under 3 months with fever, severe symptoms, breathing problems

Between urgent concerns, follow your baby's regular checkup schedule to monitor growth and development proactively.

Trusting Your Parental Instinct

Here's the most important guidance on when to call pediatrician: If something feels wrong, call.

"Something Feels Wrong"

You know your baby better than anyone. If baby "just seems off"—acting differently, looking at you differently, something you can't quite name—that's worth a call.

Pediatricians would rather you call unnecessarily 10 times than miss one serious issue. Especially in the first few weeks, err on the side of caution.

Better Safe Than Sorry

It's always okay to call and ask. Nurses and doctors who work with newborns expect frequent calls. That's literally what they're there for. You won't be "that parent who calls too much." You'll be a parent advocating for your baby.

Don't let embarrassment stop you from calling. Even if it turns out to be nothing, you learned something. And if it is something, you caught it early.

Frequently Asked Questions

My baby's temp is 99.8°F—is that a fever?

No, normal rectal temperature is 97.5-100.3°F. But if you took it rectally and it's climbing, monitor closely and call if it reaches 100.4°F. Temperatures can spike quickly in newborns.

Should I call about every little thing?

In the first few weeks, yes—err on the side of caution. Pediatricians expect and welcome frequent calls with newborns. After a month or two, you'll have a better sense of what's normal for your baby and can triage more confidently.

What if my pediatrician's office is closed?

Call the regular office number—it will route to an after-hours answering service with an on-call nurse or doctor. Alternatively, use your insurance's nurse hotline, try telemedicine, or go to urgent care or ER, depending on severity.

Is the ER necessary for a fever, or can I wait until morning?

For babies under 3 months, rectal fever of 100.4°F or higher requires immediate ER evaluation—don't wait. This age group gets thoroughly evaluated for serious bacterial infections because their immune systems can't fight them effectively yet.

How do I know if my baby is lethargic or just sleepy?

Lethargic means won't wake for feeding even when stimulated, doesn't respond to touch or sound, is completely floppy with no muscle tone, and has no alert periods. Sleepy means the baby wakes when you try, makes eye contact when roused, and can feed when woken.

Quick Reference

Call 911 - Blue colour, can't breathe, unresponsive, seizure

Call pediatrician immediately (within an hour) - Fever 100.4°F+ under 3 months, persistent vomiting, dehydration signs, inconsolable crying 3+ hours, blood in stool/vomit

Call during office hours - Rash, constipation, feeding questions, mild jaundice, development concerns

When in doubt - Call. Always.

Aspire to be prepared for your pediatrician visits? Learn what happens at each newborn checkup and how to make the most of appointment time.

Medical Disclaimer: This article provides general information and is not a substitute for professional medical advice. When in doubt, always call your pediatrician or seek emergency care.

Sources:

 Fever: When to Call the Pediatrician

https://www.healthychildren.org/English/health-issues/conditions/fever/Pages/When-to-Call-the-Pediatrician.aspx

Sutter Health - When to Call the Doctor

https://www.sutterhealth.org/health/when-to-call-baby-doctor

A Parent's Guide to Calling The Doctor

https://www.stlouischildrens.org/health-resources/pulse/parents-guide-calling-doctor