How to Avoid MAS (Meconium Aspiration Syndrome)

7 01 2014

About Meconium Aspiration-
Meconium aspiration is overhyped as conditions to create MAS (meconium aspiration syndrome) have to be right (or, wrong, as it were) for it to be an issue, and even then the attentive parent will observe problems with their neonate and be able to seek timely medical treatment if necessary.

“To date debates continue to rage regarding the optimum
obstetrical approach, resuscitation measures at birth and
subsequent management of the critically ill neonate with
meconium aspiration syndrome (MAS).” – (http://medind.nic.in/maa/t10/i2/maat10i2p152.PDF)

Risk Factors with Meconium Aspiration-
Babies that are being born in a disturbed environment or are experiencing a traumatic birth, particularly via Cesarean, are at greater risk for meconium aspiration. Almost exclusively, full term and post-dates babies are at risk of releasing meconium (not necessarily aspirating, but releasing). This can be stimulated or brought about just from normal stimulation of contractions. Seeing meconium in the fluid should not cause instant alarm and the more easy and natural the birth, and the more time the meconium has had to mix and circulate with the fluids present in baby‘s environment, the less of a threat meconium poses. Aspiration becomes less likely.

In one study of babies born with thick meconium-stained fluid, 39 developed MAS and 898 did not.
http://www.sciencedirect.com/science/article/pii/002978449500124A

Another study from Australia and New Zealand says, “A higher risk of MASINT was noted at advanced gestation, with 34% of cases born beyond 40 weeks, compared with 16% of infants without MAS. Fetal distress requiring obstetric intervention was noted in 51% of cases, and 42% were delivered by cesarean section.”

“The incidence of MASINT in the developed world is low and seems to be decreasing. Risk of MASINT is significantly greater in the presence of fetal distress and low Apgar score..”, and “Death related to MAS occurred in 24 infants (2.5% of the MASINT cohort; 0.96 per 100000 live births).”
http://pediatrics.aappublications.org/content/117/5/1712

That same publication remarks on an increase in MAS amongst home births and indigenous (minorities) within the population, but this quite possibly has a lot more to do with how individuals are treated than medical and biological predispositions.

How Do Babies Aspirate Meconium?-
If the baby passes meconium in utero, it typically mixes with the fluids in the womb. The baby has been practicing swallowing these fluids and the fluids are being replenished. If meconium is fresh and thick and the baby is soon delivered, and the meconium is by or in the airways at that time, this would pose a threat of aspiration. Aspiration may then lead to MAS, and could require medical treatment at that time. A baby having a vaginal birth where the fluids have a better opportunity to be squeezed out of the lungs and airways at birth would have less risk for aspiration and MAS. The baby does not take its first real “breath” until after birth. The baby isn’t breathing in the womb. It “practices” breathing in the womb without actually inhaling. Any aspiration would occur upon delivery. Method of delivery and birth then becomes particularly important in the presence of meconium.

This link (http://kidshealth.org/parent/medical/lungs/meconium.html#) has some alarmist medical perspectives on meconium, but take note of the following quotes:

This image seems to show meconium already settled into the lungs before the baby has taken a full breath, still in utero.

“Normally, fluid is moved in and out of only the trachea (the upper portion of the airway) when there’s breathing activity in the fetus. “

“Although 6% to 25% of babies delivered have meconium-stained amniotic fluid, not all infants who pass meconium during labor and delivery develop MAS.”

“Most babies with MAS improve within a few days or weeks”

“In some cases doctors may recommend amnioinfusion, the dilution of the amniotic fluid with saline, to wash meconium out of the amniotic sac before the baby has a chance to inhale it at birth.”

This last quote also indicates how meconium which has had the opportunity to be diluted in or cleansed from the amniotic fluids poses far less a threat to the baby. Birth should not be rushed, and meconium present is not an indication that birth should be hastened. A natural physiological birth is still called for if there are no reasons to suggest the baby is in immediate distress. Remember that meconium itself does not equal distress.

Please take heed, this, though:
“However later studies reported that this procedure [amnioinfusion] was
not accompanied by any statistically significant reduction
in adverse foetal outcomes. Moreover this procedure
had fallen into disrepute for its increased association
with foetal heart rate abnormalities, operative/instrument
deliveries and infection. “  (http://medind.nic.in/maa/t10/i2/maat10i2p152.PDF)

“Although MAS is a frightening complication for parents to face during the birth of their child, the majority of cases are not severe. Most infants are monitored for fetal distress during labor, and doctors pay careful attention to any signs that would indicate meconium aspiration.”

And so do parents. Signs of difficulty related to MAS are obvious and will not escape an educated and attentive home birthing parent. These include:

  • Bluish skin color (cyanosis) in the infant
  • Difficulty breathing (the infant needs to work hard to breathe)
  • No breathing
  • Rapid breathing
  • Limpness in infant at birth

(http://www.nlm.nih.gov/medlineplus/ency/article/001596.htm)

That last link indicates that a low APGAR may indicate needing help breathing. This is not always the case. I was transferred for meconium in fluid from my homebirth. My baby was given a lower APGAR score for color. His color was naturally pale and he had no actual complications or health conditions.

“In most cases, the outlook is excellent and there are no long-term health effects.
In more severe cases, breathing problems may occur. They usually go away in 2 – 4 days.”

“Meconium aspiration rarely leads to permanent lung damage.”

The link goes on to state:

“If the baby is active and crying, no treatment is needed.”

This was true for my baby and he was almost immediately returned to me upon inspection.

I do not advise automatic hospital transfers at the sight of meconium-stained fluids. Hospital transfer increases risk of trauma from travel, and fear/distress to mother and consequently baby. Fear causes tension in the uterus and deprives organs and fetus of blood and oxygen which increases fetal distress (and meconium release). Emergency efforts are often exaggerated and can be found to exacerbate any issues surrounding meconium (and more). Keeping birth calm and peaceful in a comfortable setting and observing the newborn at birth will be the baby’s best chance of avoiding MAS.

Treatment of Neonates w/Meconium Aspiration-

“the current evidence
suggests that intrapartum suctioning of the oro/
nasopharynx may not reduce the risk of aspiration.”

“Subsequent tracheal
toileting which was earlier advocated has been
challenged on the precincts that it is only the depressed
neonate who runs the risk of MAS.”

“It is likely that MAS
will develop in a small minority of apparently healthy
meconium stained infants, but there is no way of
identifying these neonates at risk during childbirth”

“Meconium is almost always sterile. Yet
several workers routinely administer antibiotics to the
babies with MAS… the consensus opinion does not favour the
routine use of antibiotics in babies with MAS ”

“It is necessary to maintain an optimal thermal environment and minimal handling because these infants are agitated easily and become hypoxemic and acidotic quickly.”

“Several modalities of monitoring and treatment are available, but these are yet to be substantiated with quality scientific investigation.”

(http://medind.nic.in/maa/t10/i2/maat10i2p152.pdf)

Another Good Link:
Midwife Thinking: The Curse of Meconium-Stained Liquor
One highlight: “During labour and birth it is very unlikely that a baby will inhale liquor (and any meconium in it). This will only happen if the baby becomes extremely hypoxic and begins to gasp in utero in an attempt to get oxygen. So, meconium alone is not a problem. Meconium + a hypoxic baby = the possibility of MAS (Davies & MacDonald 2008).”

I am a lay person. I am a self-educated freebirther (unassisted birther). I have left the medical birth system because I have learned how to make birth safer myself, at home. Therefore, none of this constitutes medical advice– these are my observations and opinions as I continue to grow in knowledge.