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تسجيل

Formation and composition of meconium

المؤلف:  Sue Jickells , Adam Negrusz (Editors)

المصدر:  Clarkes Analytical Forensic Toxicology

الجزء والصفحة:  p257-258

2026-10-20

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Formation and composition of meconium

Meconium is the first faecal matter passed by a neonate and is a highly complex specimen. It begins to form between the 12th and 16th weeks of gestation and usually accumulates thereafter until birth. It represents the intestinal contents of the fetus before birth and is a complex matrix, consisting mainly of water but also containing mucopolysaccharides, lipids, proteins, vernix caseosa, bile acids and salts, epithelial cells, cholesterol and sterol precursors, blood group substances, squamous cells, residual amniotic fluid and enzymes. The contents of meconium provide a history of fetal swallowing and bile excretion and it is therefore considered a more accurate history of drug use in the latter half of pregnancy than is neonatal urine. Meconium is usually passedbytheneonate1–5days afterbirth, and rarely prior to 34weeks’gestationalage.