Meconium

Definition

Meconium is the first stool passed by a newborn, typically within the first 24 to 48 hours after birth. It is composed of materials ingested during the time the infant spends in the uterus, including amniotic fluid, mucus, bile, and epithelial cells.

5 Must Know Facts For Your Next Test

1. Meconium is usually dark green in color and has a thick, sticky consistency.
2. The presence of meconium before birth can indicate fetal distress and may lead to complications such as meconium aspiration syndrome.
3. Its passage confirms that the newborn's bowel function is intact.
4. Delayed passage of meconium beyond 48 hours can be a sign of underlying conditions like Hirschsprung's disease or cystic fibrosis.
5. Meconium does not contain bacteria as it forms in the sterile environment of the uterus.

Review Questions

• What are the primary components of meconium?
• Why might delayed passage of meconium be clinically significant?
• How does meconium differ from subsequent stools in a newborn?

Related terms

Hirschsprung's Disease: A congenital condition where nerve cells are missing from parts of the intestine, causing severe constipation or intestinal obstruction.

Meconium Aspiration Syndrome: A serious condition where a newborn inhales a mixture of meconium and amniotic fluid into the lungs around the time of delivery.

Amniotic Fluid: The protective liquid contained within the amniotic sac that surrounds and cushions a fetus during pregnancy.