Meconium staining of the skin and meconium aspiration in porcine intrapartum stillbirths

Abstract

Rates and severity of meconium staining on skin and meconium aspiration into the respiratory tract of porcine intrapartum stillbirths were determined in an intensively managed farm. Heartbeats, inspiratory efforts and umbilical cord morphology were evaluated at birth. The lungs of all intrapartum stillborn piglets were grossly examined and microscopically evaluated for the presence of amniotic fluid cells, meconium and inflammatory cells. Thirty four percent of the intrapartum stillbirths had ruptured umbilical cords. Heartbeats and inspiratory efforts were rarely detectable. All intrapartum stillbirths (100%) were stained with meconium, and 60% had meconium grossly visible in the oropharynx and 40% in trachea and bronchi. Microscopically, 72% of the lungs contained meconium. The most common site where meconium was found was the bronchi (66%) followed by bronchioles (48%), and alveoli (34%). There was no microscopic evidence of inflammation in lungs with meconium aspiration. No significant association was found between the severity of skin staining and the degree of meconium aspiration. It was concluded that meconium staining is consistently present in intrapartum stillbirths suggesting that severe hypoxia takes place during parturition. However, meconium staining appears to be a poor predictor for intrapartum aspiration in stillbirth piglets. These findings also suggest that intrapartum death due to asphyxia occurs rapidly thus providing insufficient time in the stillborn to mount a typical inflammatory response in the lung. D 2006 Elsevier B.V. All rights reserved.