What is "meconium"

Meconium \Me*co"ni*um\, n. [L., fr. Gr. ?, fr. ? poppy.] (Med.)

1. Opium. [Obs.]

2. The contents of the fetal intestine; hence, first excrement.

"fecal discharge from a newborn infant," 1706, from Latin meconium "excrement of a newborn child," literally "poppy juice," from Greek mekonion "poppy-juice, opium," diminutive of mekon "poppy" (perhaps cognate with Old Church Slavonic maku, German Mohn "poppy"). So called by classical physicians for its resemblance. Related: Meconial.

n. 1 (context medicine English) A dark green mass, the contents of the fetal intestines during the later stages of mammalian gestation, that forms the first faeces of the newborn 2 (context obsolete English) opium

n. thick dark green mucoid material that is the first feces of a newborn child

Meconium is the earliest stool of a mammalian infant. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amniotic fluid, bile, and water. Meconium, unlike later feces, is viscous and sticky like tar, its color usually being a very dark olive green; it is almost odorless. When diluted in amniotic fluid, it may appear in various shades of green, brown, or yellow. It should be completely passed by the end of the first few days after birth, with the stools progressing toward yellow (digested milk).

Meconium is normally retained in the infant's bowel until after birth, but sometimes it is expelled into the amniotic fluid (also called "amniotic liquor") prior to birth or during labor and delivery. The stained amniotic fluid (called "meconium liquor" or "meconium stained liquor") is recognised by medical staff that this may be a sign of fetal distress. Some post-dates pregnancies (where the woman is more than 40 weeks pregnant) may also have meconium stained liquor without fetal distress. Medical staff may aspirate the meconium from the nose and mouth of a newborn immediately after delivery in the event the baby shows signs of respiratory distress to decrease the risk of meconium aspiration syndrome.

Meconium had been thought to be sterile until the team of researchers from the University of Valencia in Spain found bacterial communities in it so developed that they seemed to fall into two categories. Around half of the samples appeared to be dominated by bacteria that produce lactic acid, such as lactobacillus, while the other half mostly contained a family of so-called enteric bacteria, such as Escherichia coli.

The Latin term meconium derives from the Greek , mēkōnion, a diminutive of , mēkōn, i.e. poppy, in reference either to its tarry appearance that may resemble some raw opium preparations, or to Aristotle's belief that it induces sleep in the fetus.

A symptom of both Hirschsprung's disease and cystic fibrosis is the failure to pass meconium.

Meconium can be tested for various drugs, to check for in utero exposure. Using meconium, a Canadian research group at the Hospital for Sick Children, University of Toronto, showed that by measuring a by-product of alcohol (FAEE) they could objectively detect babies exposed to excessive maternal drinking of alcohol in pregnancy. In the USA, the results of meconium testing may be used by child protective services and other law enforcement agencies to determine the eligibility of the parents to keep the newborn.