Definition of decidua in English:



mass nounPhysiology
  • The thick layer of modified mucous membrane which lines the uterus during pregnancy and is shed with the afterbirth.

    • ‘Extreme care is used in inspecting the placenta and membranes in an effort to insure complete expression of the entire decidua.’
    • ‘Ectopic decidua was found in 3% of the specimens and could be seen in both subserosal and plical areas, and was found only in postpartum patients.’
    • ‘There were large amounts of polarizable foreign body material contained within the membranes and maternal decidua, without associated inflammation or tissue reaction.’
    • ‘The tissue is sent to the laboratory where the fetal villi are dissected from the maternal decidua and either processed directly or cultured for chromosomal, DNA or biochemical analysis.’
    • ‘One mechanism by which microorganisms might cause preterm labor is through ascension from the cervical/vaginal area and replication in the placenta, decidua and membranes.’


Late 18th century: from modern Latin decidua (membrana), literally ‘falling off (membrane)’.