What is a common early symptom of cystic fibrosis seen in newborns?

Meconium ileus is indeed a common early symptom of cystic fibrosis observed in newborns. In cystic fibrosis, the thick and sticky mucus that characterizes the disease can obstruct the intestines, particularly leading to meconium ileus, which is a blockage that occurs when the meconium (a newborn's first bowel movement) becomes abnormally thick and sticky. This can result in severe gastrointestinal issues shortly after birth.

This symptom is particularly significant in cystic fibrosis because the condition affects the exocrine glands, leading to the production of abnormally thick mucus not just in the lungs, but also in other organs, including the pancreas and intestines. The presence of meconium ileus in a newborn can be an early indicator of cystic fibrosis, prompting further diagnostic evaluation for this genetic disorder.

Other symptoms listed, such as a persistent cough, excessive sweating, and frequent vomiting, can occur in cystic fibrosis but are not typically the earliest signs noticed in newborns. Persistent cough is often seen as the child grows older, excessive sweating can occur due to salt loss but usually doesn't present as a deliberate symptom at birth, and frequent vomiting can result from multiple gastrointestinal issues but is not a definitive early indicator of cystic fibrosis.