Even though meconium can cause problems for some babies during childbirth, what few parents today realize is that most of the time the presence of meconium is not a risk to their baby. What are some important facts to know about meconium?
What is Meconium?
Meconium is a sticky, dark green, tar-like substance that forms in the baby's intestinal tract in utero in the last trimester of pregnancy, especially as the mother approaches her due date.
Meconium is made up of water, amniotic fluid, hair (lanugo), mucous and bile. Believe it or not, meconium is actually quite different from stool or excrement. Despite the fact that it can cause complications during birth, meconium itself is sterile and does not contain bacteria.
How Often Does Meconium Staining Occur?
Studies have shown that meconium staining is present in about 8-25% of all births. Most of the time, meconium that is passed during labor does not cause complications. This is especially true if the meconium staining is very light or the meconium is behind the baby when she is born.
However, in births where meconium is observed, 10% of all newborns will aspirate the meconium before or during the labor process. Meconium aspiration can cause the newborn to become very sick.
What are the Risk Factors for Meconium During Labor?
There are some labor situations in which the baby is more likely to pass meconium in utero, including the following:
- problems with placental functioning
- mothers with high blood pressure (hypertension)
- preeclampsia
- lower than normal amount of amniotic fluid (oligohydramnios)
- maternal smoking
- use of street drugs such as cocaine
- going past due date by two weeks (42 weeks gestation)
- maternal infection (chorioamnionitis)
It is important to realize that the baby can pass meconium during labor even when none of these problems or complications are present with mother or her baby.
What Happens if the Baby Inhales Meconium During Labor?
As soon as the care provider notices that meconium is present during labor, he or she will assess the consistency of the meconium. Some research suggests that if meconium is thick (as in consistency and color) then it is more likely to cause problems for the baby.
One of the biggest risks of the baby inhaling meconium is pneumonia. This often occurs as the baby takes her first breaths after she is born. For that reason, the care provider will be certain to suction as much meconium from the baby's mouth and nose as possible, even prior to the baby taking her first breaths, to decrease the risk of pneumonia.
At times if the meconium is found lower in the baby's respiratory tract, deeper suctioning is needed. Babies who have inhaled meconium may need to remain longer in the hospital's NICU, treated with ventilation, oxygen and IV antibiotics.
Can Meconium Aspiration be Prevented?
More care providers today are trying to prevent meconium aspiration in a number of ways. One is to try to detect problems with the baby's heart rate during labor using electronic fetal monitoring. Another method to prevent the baby from inhaling meconium is to use amnioinfusion, where additional fluids are added to uterus. Encouraging a labor induction when the mother is postdates (after 42 weeks) can also reduce the risk of meconium during labor.
Some researchers have also noted that the increased use of cesareans in the last 10 years have also decreased the amount of meconium aspiration among newborns; however, this comes at the high price of additional surgical risks to the mother from having a cesarean.
Parents who are planning for childbirth need not worry unnecessarily about meconium and the possible complications it can cause during labor. Care providers are trained to assess meconium when it is present and in ways to prevent meconium aspiration. Simply knowing how possible complications such as the presence of meconium are handled is an important way for expectant parents to prepare for the unexpected.
References:
EMedicine, Web MD
Merck.com
Yoder, BA., "Changing obstetric practices associated with decreased incidence of meconium aspiration syndrome," Obstetrics and Gynecology, May 2002.
Brenda Lane - Brenda Lane is a published author, Lamaze certified childbirth educator, DONA certified birth doula and approved birth doula trainer.
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