Meconium-stained amniotic fluid and histologic signs of fetal distress in stillbirths

Abstract

Objective: Stillbirth is one of the most devastating adverse pregnancy outcome, but it is often associated with a missing post-mortem histological examination. We aimed at evaluating whether the staining of amniotic fluid reflects the fetal conditions surrounding the death and if it correlates with any histologic sign of fetal distress.

Study design: Terminal gasping (represented by the massive presence of intra-alveolar squamous cells), thymic and adrenal cortex modifications were evaluated as histologic signs of fetal distress in stillbirths, and stratified according to the degree of staining of the amniotic fluid.

Results: The presence of meconium-stained amniotic fluid did not correlate with the presence of gasping and/or thymic and/or adrenal cortex changes. Clear amniotic fluid was not associated with the absence of histologic signs of distress.

Conclusions: The evaluation of the staining of the amniotic fluid fails to identify distressed fetuses. A histologic evaluation of fetal organs provides detailed information, irrespective of the presence/absence of meconium-stained amniotic fluid.

Keywords: Adrenal cortex; Fetal autopsy; Gasping; Meconium; Stillbirth; Thymus.