Meconium

Though it might gross you out, especially when you’re just learning the art of changing nappies and what happens down under, meconium, that green tar-like stuff in your newborn’s nappy, is a good sign.

What is it?

In a nutshell, meconium is a baby’s first poop – the earliest stool your newborn will pass after birth. Unlike other faecal matter, which is made up of what your baby digests, meconium is comprised of what lined her intestines in utero. It’s formed from the baby’s skin cells, blood, hair and mucous that are shed into the amniotic fluid. During pregnancy, a baby will swallow amniotic fluid, and the waste builds up in her intestines as meconium. Though it looks thick, green and tar-like, meconium is usually sterile and has no smell. It is sticky and a little more difficult to clean than most poops, so don’t worry or think every bowel movement will be like this. 

Most babies pass the first meconium stool in the first twelve hours after birth and is either passed only once by your baby, or takes a few days to leave her system completely. Once it has passed initially, a baby’s stool will become softer and more watery owing to the breastmilk or formula she drinks.

When your doctor will intervene

Typically meconium is not released inyour baby’s bowel movements until afterbirth. However, occasionally babies willhave a bowel movement before birth,excreting the meconium into the amniotic uid. Babies who become stressed forsome reason might excrete the meconium,which then becomes mixed with amniotic uid and can get into the lungs.

This is known as meconium aspiration, also referred to as meconium aspiration syndrome (MAS). Although it can be serious, most cases of MAS aren’t.

MAS can happen before, during, or after labour and delivery when a newborn inhales (or aspirates) a mixture of meconium and amniotic uid (the fluid in which the baby oats inside the amniotic sac). The inhaled meconium can partially or completely block the baby’s airways, and even though air can flow past the meconium trapped in the baby’s airways as the baby breathes in, the meconium becomes trapped in the airways when the baby breathes out. And so, the inhaled meconium irritates the baby’s airways and makes it difficult for her to breathe.

The severity of MAS depends on the amount of meconium the baby inhalesas well as underlying conditions, such as infections within the uterus or postmaturity (when a baby is overdue,or more than 40 weeks’ gestational age). Generally, the more meconium a baby inhales, the more serious the condition. MAS can also lead to meconium aspiration pneumonia, which will require treatment, and a possible stay in the neonatal intensive care unit.

There is no way to know if meconium has passed until the birth of the baby, but the colour of the water when it breaks is a good indicator. A normal colour would be a clear one and one with meconium could be either green or yellow. Yellow indicates the meconium is very old and has been inside the uterus for an unknown amount of time, while green means it is more recent and if it has particles to it, poses more of a health risk to the baby.

If meconium is present during your labour and birth, you will be watched more closely for signs of foetal distress. Alone, meconium staining of the amniotic fluid does not mean that your baby is suffering from fetal distress. However, since it is just one sign, your doctor or birth team will monitor closely. There is no way to prevent meconium from being passed before birth so new mothers shouldn’t spend time worrying about it. If it does happen, having a competent doctor who can handle the situation can prevent complications.

Treatment

When meconium is noticed during labour and delivery is imminent, your doctor will use a suction just before the baby takes her first breath, to clear the meconium before the lungs expand or the meconiumis aspirated into the respiratory system. Your doctor might also choose amnioin fusion where sterile fluid is placed inside the uterus via a catheter to help dilute the meconium present.