Neonatal aspiration syndrome due to vernix caseosa.

Fetal aspiration of meconium in amniotic fluid is a well-known cause of respiratory distress in newborn infants. It causes an irregular, coarse, nodular pattern on chest radiographs. Less known is that aspiration of vernix caseosa causes a similar syndrome. We present a post-mature infant in whom aspiration of vernix caseosa caused respiratory distress, ventilatory difficulty, and radiographic changes essentially the same as in aspiration of meconium.