[Meconium and its significance]

Abstract

Objective: A review of meconium patophysiology and its contribution to the incidence of perinatal infection.

Design: Review article.

Setting: Department of Gynaecology and Obstetrics, Charles University and Faculty Hospital Plzen, Czech Republic.

Method: The reported incidence of meconium-stained amniotic fluid varies between 7 and 22%. The patophysiology of the presence of meconium in the amniotic fluid is not sufficiently explained. Meconium in fetal bowels is under hormonal and neurol control. The presence of the meconium-stained amniotic fluid was always considered to be a potential risk for the fetal and neonatal well-being. The review is further divided in to three chapters. (II. Meconium and meconium aspiration syndrome, III. Meconium and postnatal neurological handicap).

Results and conclusion: The first chapter on deals with meconium risk in the development of perinatal infection: intraamniotic infection/chorioamnionitis, postnatal endometritis, infection of the abdominal wound after Caesarean and neonatal infection. The incidence of clinical chorioamnionitis is 15% with the presence of meconium compared to 3% in controls. The incidence of puerperal endometritis is 10% in comparison to 3% under normal conditions. Two main mechanisms of development (or coincidence) of intraamniotic infection in the presence of meconium exist. 1) Infection may be a cause of meconium passage. 2A) Alteration of Zn/P ratio in the amniotic fluid can promote bacterial growth. 2B) Meconium attached to macrophages or absorbed by phagocytosis can impair cellular immune response. The antibiotic prophylaxis is discussed.