amnion nodosum
Pronunciation: AM-nee-on no-DO-sum
Small nodular deposits on the amnion surface associated with severe oligohydramnios and fetal renal abnormalities.
Full Definition
Amnion nodosum refers to small, white or yellow nodular deposits that appear on the fetal surface of the amnion in cases of severe oligohydramnios. These nodules consist of vernix caseosa, fetal hair, and desquamated fetal skin cells that normally would be suspended in amniotic fluid but instead adhere to the amnion when fluid levels are severely decreased. The finding is pathognomonic for prolonged severe oligohydramnios and is strongly associated with fetal renal abnormalities and pulmonary hypoplasia.
Usage
Usage note: Finding is pathognomonic for severe oligohydramnios; always investigate for renal abnormalities.
In Context
- "Placental examination revealed amnion nodosum consistent with prolonged severe oligohydramnios." — Pathology report
- "The presence of amnion nodosum confirmed the clinical suspicion of fetal renal agenesis." — Perinatal autopsy findings