Croup (laryngotracheobronchitis) is a common respiratory illness primarily affecting young children. It is characterized by the swelling of the voice box and windpipe, which leads to the distinctive “seal-bark” cough. While mostly a childhood concern, its contagiousness becomes relevant when a pregnant adult is in the household. Understanding the viral nature of this infection and its differing presentation in adults is important during pregnancy.
The Viral Cause and Transmission
Croup is highly contagious and caused by a group of easily spread viruses. The most frequent cause is the human parainfluenza virus (HPIV), particularly types 1 and 3. Other viruses, such as Respiratory Syncytial Virus (RSV), influenza viruses, adenovirus, and some coronaviruses, can also trigger the condition.
Transmission occurs primarily through respiratory droplets released when an infected person coughs, sneezes, or talks. The virus can also survive on surfaces, meaning contact transmission is possible if a person touches a contaminated object and then touches their mouth, nose, or eyes. The contagious period typically begins before symptoms appear and lasts until the fever has resolved, often a week to ten days. Pregnant adults can contract these viruses from infected children, though the resulting illness often manifests differently.
How Croup Presents in Adults
The classic, loud, barking cough seen in children is rare in adults, including pregnant individuals, due to anatomical differences in the respiratory system. Children have narrower windpipes and vocal cords, so the inflammation severely limits airflow, producing the characteristic sound. An adult’s larger airway is less susceptible to significant obstruction from the same degree of swelling.
When a pregnant adult contracts one of the viruses that causes croup, the illness typically presents as a mild upper respiratory infection resembling a common cold or laryngitis. Individuals may experience hoarseness, a sore throat, general malaise, or a persistent cough. In rare instances, adults can develop the full syndrome with stridor—a high-pitched, noisy breathing sound. This presentation is serious and requires prompt medical attention.
Implications for Pregnancy and Fetal Health
The primary concern with a viral infection like croup during pregnancy is not usually a direct risk to the fetus. The viruses responsible generally do not cross the placenta to cause birth defects or severe fetal illness. Instead, the greatest risk stems from secondary complications in the pregnant person, particularly high fever and respiratory distress.
A sustained high fever, especially in the first trimester, can pose a risk to the developing fetus, making fever management a priority. The physiological changes of pregnancy, such as increased oxygen demand and reduced lung capacity, can make respiratory infections more difficult to manage. Pregnant people may experience more severe symptoms than non-pregnant adults, increasing the chance of respiratory distress.
Management focuses on supportive care and safe symptom relief to protect both the pregnant person and the fetus. Acetaminophen (paracetamol) is the recommended medication for reducing fever and alleviating aches, and is considered safe for use throughout pregnancy when taken as directed. Adequate hydration is necessary to thin secretions and prevent dehydration, which can be linked to complications like preterm labor.
Certain over-the-counter medications, such as decongestants containing pseudoephedrine or phenylephrine, are often discouraged or should only be used after consulting a healthcare provider. Steam therapy from a hot shower or cool-mist humidifiers can help soothe the inflamed airways and ease breathing. When symptoms persist or worsen, medical consultation becomes necessary. Immediate medical attention should be sought if the pregnant person experiences signs of severe respiratory distress, such as difficulty breathing, stridor at rest, or a sustained inability to keep the fever down. Promptly addressing these complications minimizes the risk of adverse outcomes, including preterm labor.