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).
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By Age
What to expect by age
0-2 months
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.
2-6 months
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.
6-12 months
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.
12-36 months
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
Trust your instincts. If something feels wrong, reach out to your pediatrician.
Worrying about your baby means you care. That is a good thing.
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.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.
Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.