Whooping Cough (Pertussis) in Babies
The short answer
Whooping cough (pertussis) is a serious bacterial respiratory infection that is most dangerous for babies under 12 months who have not completed their vaccine series. It begins like a mild cold but progresses to severe coughing fits that can last for weeks. Babies may not "whoop" - instead they may gasp, turn red or blue, or stop breathing briefly during coughing episodes. Pertussis in young infants is a medical emergency. It is preventable through vaccination (DTaP for babies, Tdap for pregnant women and caregivers).
By Age
What to expect by age
Babies under 2 months are at the highest risk for severe pertussis because they have not yet received their first DTaP vaccine dose (given at 2 months). Protection depends on maternal Tdap vaccination during pregnancy (which passes antibodies) and cocooning (all close contacts being vaccinated). In very young infants, pertussis may not present with the classic cough - instead watch for episodes of apnea (pauses in breathing), feeding difficulty, and turning blue. Hospitalization is often required.
Babies begin their DTaP vaccine series at 2 months, with additional doses at 4 and 6 months. They are not fully protected until they have had multiple doses. Pertussis in this age group typically starts as a cold (runny nose, mild cough) for 1-2 weeks, then progresses to severe coughing fits. These fits can cause the baby to turn red or purple, vomit after coughing, or make a "whoop" sound when gasping for air between coughs. Contact your pediatrician immediately if you suspect pertussis.
With continued vaccination, babies become better protected but are still vulnerable. The characteristic coughing fits can last 1-6 weeks even with antibiotic treatment. Antibiotics (typically azithromycin) do not cure the cough but prevent the infected child from spreading pertussis to others. During coughing episodes, keep your baby calm and upright. Frequent small feeds help maintain nutrition since babies often vomit during or after coughing fits.
Pertussis in older babies and toddlers who have received most of their DTaP doses is generally less severe but can still cause weeks of miserable coughing. The classic pattern is paroxysms of rapid coughing followed by a high-pitched "whoop" when inhaling. This can persist for 6-10 weeks, earning pertussis the nickname "the 100-day cough." Close contacts should be treated with prophylactic antibiotics regardless of vaccination status.
What Should You Do?
When to take action
- Your baby has a mild cold with runny nose and no coughing fits - most colds are not pertussis
- Your baby coughs occasionally during a cold but can feed normally and does not have coughing paroxysms
- Your fully vaccinated toddler has a lingering cough after a cold that is gradually improving
- Your baby has a cough that is getting worse after the first week rather than better
- Your baby has coughing fits that end with vomiting, even if the fits are not yet severe
- You or someone in close contact with your baby has been diagnosed with or exposed to pertussis
- Your baby has severe coughing episodes where they cannot catch their breath, turn blue or red, or gasp with a "whoop" sound - seek emergency care
- Your baby stops breathing during or after a coughing fit (apnea), even briefly
- Your baby under 3 months has any persistent cough that is worsening, especially if not yet vaccinated
Sources
Related Resources
Related Medical Concerns
My Baby Coughs a Lot
Coughing is a natural reflex that helps clear the airways. In babies, the most common cause of coughing is a viral upper respiratory infection (common cold), which can cause a cough lasting 1-3 weeks. While most coughs are not serious, certain types of cough (barking, whooping, or persistent) or coughs accompanied by breathing difficulty warrant medical evaluation.
My Baby Coughs Mostly at Night
Nighttime coughing in babies is very common and often worse than daytime coughing because lying down allows mucus to pool in the back of the throat, and cool night air can irritate sensitive airways. The most common causes are colds with postnasal drip, croup, and asthma or reactive airways. While usually manageable at home, a barking cough with stridor (noisy breathing in) or any breathing difficulty at night needs prompt evaluation.
My Baby Is Breathing Fast
Babies normally breathe faster than adults. A normal respiratory rate for a newborn is 30-60 breaths per minute, slowing to 20-40 by age 1. Brief episodes of faster breathing during excitement, crying, or feeding are normal. However, persistently rapid breathing (tachypnea) at rest, especially with other signs of respiratory distress, may indicate a lung or heart problem that needs prompt evaluation.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
I'm Worried About Lazy Eye (Amblyopia)
Amblyopia (lazy eye) is the most common cause of vision loss in children, affecting about 2-3% of kids. It occurs when one eye develops weaker vision because the brain favors the other eye. The tricky part is that amblyopia often has no obvious outward signs - the eye usually looks normal. Early detection through routine vision screening is critical because treatment is most effective in the first few years of life.
Anaphylaxis Signs in Baby
Anaphylaxis is a severe, potentially life-threatening allergic reaction that affects multiple body systems. In babies, it can be caused by food (most commonly), insect stings, or medications. Signs include widespread hives, facial or throat swelling, difficulty breathing, persistent vomiting, and becoming limp or unresponsive. Anaphylaxis is a medical emergency. If you suspect anaphylaxis, use an epinephrine auto-injector if available and call 911 immediately. Early recognition and rapid treatment lead to excellent outcomes in the vast majority of cases.