What Causes Meconium Aspiration Syndrome?
Meconium aspiration syndrome (MAS) is caused by a newborn ingesting or inhaling a mix of amniotic fluid and meconium (a dark green substance that is the baby’s first feces).
Babies usually pass meconium in the first few hours or days following birth. However, some babies pass meconium while they are still in the womb, which means it gets mixed into the amniotic fluid.
When a baby is under stress, they may forcefully gasp the mixture into their lungs, putting them at risk for meconium aspiration syndrome.
“[Meconium aspiration syndrome] typically occurs when the fetus is stressed during labor, especially when the infant is past its due date.”
To follow are some risk factors that contribute to meconium aspiration syndrome causes.
Meconium Aspiration Syndrome Risk Factors
The top risk factor for what causes meconium aspiration syndrome is fetal distress. However, other situations can make MAS more likely to occur.
- Health issues in the mother: If the baby’s mother has a health issue like diabetes or high blood pressure, the infant is more likely to be stressed before or during birth.
- Intrauterine growth restriction (IUGR): This occurs when the fetal weight is below the 10th percentile for gestational age.
- Lack of oxygen: Babies with low oxygen levels are more likely to gasp, which can be what causes meconium aspiration syndrome.
- Post-term pregnancy: A baby born after their due date may be stressed due to the aging placenta. As a result, they are more likely to pass meconium while still in the womb.
- Prolonged or difficult delivery: Babies born after a long or hard delivery are more likely to pass meconium due to fetal distress. While in distress, a baby may gasp while still in the womb or soon after delivery.
- Smoking: Mothers who smoke during pregnancy are more likely to have infants with MAS, potentially due to how tobacco smoke affects the baby’s breathing patterns.
If you have questions about meconium aspiration syndrome causes, our registered labor and delivery nurses are here to help.
Common Symptoms of Meconium Aspiration Syndrome
Symptoms of MAS can vary for each baby, but there are some common ones to watch out for.
Symptoms of meconium aspiration syndrome include:
- Bluish skin color
- Body limpness
- Difficulty breathing (respiratory distress)
- Grunting when breathing
- Meconium-stained amniotic fluid
- Rapid breathing
- Slow heart rate
How Is Meconium Aspiration Syndrome Diagnosed?
Doctors can diagnose MAS before or shortly after birth with various tests.
- Blood gas analysis: Babies with meconium aspiration syndrome may show signs of low blood acidity, increased carbon dioxide, and decreased oxygen.
- Chest X-ray: Diagnostic images of babies with meconium aspiration syndrome are likely to show streaky or patchy areas on the lungs.
- Laryngoscopy: Infants with meconium aspiration syndrome could have stains on the vocal cords. Doctors can use a laryngoscope to look for these stains.
Meconium Aspiration Syndrome Complications
Meconium aspiration syndrome can make it harder for your newborn to breathe.
This is because the inhaled meconium can:
- Block the airways
- Injure the baby’s lungs
- Irritate the airways
If obstetricians fail to diagnose and treat meconium aspiration syndrome in time, MAS may cause permanent lung damage.
In severe cases of meconium aspiration syndrome, the baby may suffer brain damage or even death if there is a prolonged lack of oxygen while they are in the uterus.
- Behavioral effects: Brain damage can cause an exaggeration of personality characteristics like anger or agitation.
- Cognitive effects: Brain injuries can change a child’s thinking, learning, and perceiving ability. Children may have difficulties remembering and understanding events, concepts, and people.
- Communication problems: Children with brain damage may find communicating through physical movements or spoken language challenging.
- Physical effects: Brain injuries can cause problems with coordination, mobility, balance, and muscle weakness. They may also develop long-term health issues like chronic lung disease and asthma.
MAS can also cause persistent pulmonary hypertension of the newborn (PPHN). This rare but serious condition affects the blood flow to and from the lungs.
According to Cleveland Clinic, meconium aspiration syndrome is one of the top causes of PPHN.
Sometimes, parents are unaware that their baby suffered from brain damage due to meconium aspiration syndrome. This is because symptoms are not always obvious.
Developmental delays can be an early sign of newborn brain damage. If you suspect your baby may be at risk for brain damage due to MAS, take our free developmental milestone quiz now.
IS YOUR CHILD MISSING DEVELOPMENTAL MILESTONES?
Take Our Milestones Quiz
Taking note of your child’s physical, social, and emotional skills can help you determine if they potentially suffered from an injury at birth. An early diagnosis can help your child get the treatment they need as soon as possible.
Q1: How old is your child?
0-2 MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Can your child hold their head steadily on their own?
- Q3: Can your child push themselves up when they are lying on their stomach?
- Q4: Has your child started to make smoother movements with their arms and legs?
- Q5: Does your child smile at other people?
- Q6: Can your child bring their hands to their mouth?
- Q7: Does your child turn their head when they hear a noise?
- Q8: Does your child coo or make gurgling noises?
- Q9: Does your child follow things with their eyes?
- Q10: Does your child try to look at their parents or caregivers?
- Q11: Does your child show boredom, cry, or fuss when engaged in an activity that hasn’t changed in a while?
3-4 MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Can your child hold their head steadily on their own?
- Q3: Does your child push down on their legs when their feet are on a flat surface?
- Q4: Has your child started to roll over from their stomach to their back?
- Q5: Can your child hold and shake a toy such as a rattle?
- Q6: Does your child bring their hands to their mouth?
- Q7: Does your child play with people and start to cry when the playing stops?
- Q8: Does your child smile spontaneously, especially at people?
- Q9: Does your child copy some movements and facial expressions of other people?
- Q10: Does your child babble with expressions and copy sounds they hear?
- Q11: Does your child cry in different ways to show hunger, pain, or tiredness?
- Q12: Does your child respond to affection like hugging or kissing?
- Q13: Does your child follow moving things with their eyes from side to side?
- Q14: Does your child recognize familiar people at a distance?
5-6 MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Can your child roll over on both sides (front to back/back to front)?
- Q3: Has your child begun to sit without support?
- Q4: Does your child rock back and forth?
- Q5: Can your child support their weight on their legs (and perhaps bounce) when standing?
- Q6: Has your child begun to pass things from one hand to the other?
- Q7: Does your child bring objects such as toys to their mouth?
- Q8: Does your child know if someone is not familiar to them and is a stranger?
- Q9: Does your child respond to other people’s emotions, such as a smile or a frown?
- Q10: Does your child enjoy looking at themselves in the mirror?
- Q11: Does your child look at things around them?
- Q12: Does your child respond to sounds they hear by making sounds themselves?
- Q13: Does your child make sounds to show joy or displeasure?
- Q14: Does your child respond to their own name?
- Q15: Has your child started to string vowels together, such as "ah," "eh," or "oh," or started to say consonant sounds such as "m" or "b"?
- Q16: Has your child begun to laugh?
7-9 MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Can your child crawl?
- Q3: Can your child stand while holding on to something to support them?
- Q4: Can your child sit without support?
- Q5: Can your child pull themselves up to stand?
- Q6: Does your child play peekaboo?
- Q7: Can your child move things from one hand to the other?
- Q8: Can your child pick small things up, such as a piece of cereal, with their thumb and index finger?
- Q9: Does your child look for things that they see you hide?
- Q10: Does your child watch the path of something as it falls?
- Q11: Does your child show fear when around strangers?
- Q12: Does your child become clingy with adults who are familiar to them?
- Q13: Does your child have favorite toys?
- Q14: Does your child use their fingers to point?
- Q15: Does your child understand “no”?
- Q16: Does your child make a lot of repetitive sounds, such as “mamama” or “bababa”?
- Q17: Does your child copy the sounds and gestures of other people?
10-12 MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Can your child stand alone with no support?
- Q3: Does your child walk while holding on to furniture?
- Q4: Can your child take a few steps without holding on to anything?
- Q5: Can your child get into a sitting position without any help?
- Q6: Does your child bang two things together when playing?
- Q7: Does your child poke with their index finger?
- Q8: Has your child started to use things like hairbrushes or drinking cups correctly?
- Q9: Does your child find hidden objects easily?
- Q10: Does your child play peekaboo or pat-a-cake?
- Q11: Does your child become shy or nervous around strangers?
- Q12: Does your child repeat actions or sounds to get attention?
- Q13: Does your child put out an arm or leg to help when getting dressed?
- Q14: Does your child cry when a parent leaves the room?
- Q15: Does your child show that they have favorite things or people?
- Q16: Does your child show fear?
- Q17: Does your child say things such as “mama,” “dada,” or “uh-oh”?
- Q18: Does your child try to say the words you say?
- Q19: Has your child started to use gestures like waving or shaking their head “no”?
13-18 MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Can your child walk by themselves?
- Q3: Does your child walk up stairs and run?
- Q4: Does your child pull toys while walking?
- Q5: Can your child drink from a cup on their own?
- Q6: Can your child eat with a spoon on their own?
- Q7: Can your child help undress themselves?
- Q8: Does your child have occasional temper tantrums?
- Q9: Does your child show affection to familiar people?
- Q10: Does your child become clingy in new situations?
- Q11: Does your child explore their environment alone with parents close by?
- Q12: Can your child say several single words?
- Q13: Can your child say and shake their head “no”?
- Q14: Does your child point to show things to other people?
- Q15: Does your child scribble?
- Q16: Does your child know what ordinary products such as phones, spoons, and brushes are used for?
- Q17: Can your child follow one-step commands such as “sit down” or “stand up”?
- Q18: Does your child play with a doll or stuffed animal by pretending to feed it?
19-23 MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Has your child begun to run?
- Q3: Has your child kicked a ball?
- Q4: Can your child climb down and onto furniture on their own?
- Q5: Can your child walk up and down stairs while holding on?
- Q6: Can your child stand on their tiptoes?
- Q7: Has your child thrown a ball overhand?
- Q8: Does your child copy others, especially people older than them?
- Q9: Does your child get excited around other children?
- Q10: Has your child shown more independence as they've aged?
- Q11: Does your child do what they were told not to do and become defiant?
- Q12: Does your child point to things when they are named?
- Q13: Does your child know names of familiar people or body parts?
- Q14: Does your child say 2 to 4-word sentences?
- Q15: Does your child repeat words they hear?
- Q16: Does your child complete sentences and rhymes in familiar books?
- Q17: Does your child name items in books, such as dogs, cats, and birds?
- Q18: Does your child play simple pretend games?
- Q19: Has your child started to use one hand more than the other?
- Q20: Has your child begun to sort shapes and colors?
- Q21: Does your child follow 2-step instructions, such as “pick up your hat and put it on your head?”
24+ MONTHS DEVELOPMENTAL MILESTONES QUIZ
- Q2: Can your child run easily?
- Q3: Can your child climb?
- Q4: Can your child walk up and down stairs with one foot on each step?
- Q5: Can your child dress and undress themselves?
- Q6: Does your child show affection for friends without being told?
- Q7: Does your child take turns when playing games?
- Q8: Does your child show concern when others are crying?
- Q9: Does your child understand the idea of “mine" and "theirs"?
- Q10: Does your child show many different emotions?
- Q11: Does your child copy adults and friends?
- Q12: Does your child separate easily from their parents?
- Q13: Does your child get upset when there is a major change in their routine?
- Q14: Does your child say words such as “I,” “me,” “we,” “you,” and some plural nouns?
- Q15: Can your child say their first name, age, and gender?
- Q16: Can your child carry on a conversation with 2 to 3 sentences?
- Q17: Can your child work toys with buttons and other moving parts?
- Q18: Does your child play pretend with dolls, animals, or people?
- Q19: Can your child finish 3 or 4 piece puzzles?
- Q20: Can your child copy a circle when drawing?
- Q21: Can your child turn pages of a book one page at a time?
- Q22: Can your child turn door handles?
Treatment for Meconium Aspiration Syndrome
When doctors detect meconium aspiration syndrome, they will suction the baby’s mouth during delivery. The healthcare team will provide further treatment if fetal distress is accompanied by thick meconium staining.
Babies with meconium aspiration syndrome typically need special care in the neonatal intensive care unit (NICU). The healthcare team will give the baby oxygen for breathing difficulties as needed. They may use a CPAP machine, face mask, or breathing tube.
- Antibiotics to fight infections
- Chest tapping to loosen secretions
- Extracorporeal membrane oxygenation (ECMO) for pumping blood
- Inhaled nitric oxide for opening blood vessels
- Surfactant for opening the lungs
- Warmer to maintain normal body temperature
Most infants with meconium aspiration syndrome recover within several days to a few weeks, depending on the amount of meconium inhaled.
Meconium Aspiration Syndrome and Medical Negligence
Doctors and hospitals should have the medical expertise to treat or diagnose meconium aspiration syndrome promptly. Failure to do so can cause severe problems for the baby, including brain damage or even death.
Severe meconium aspiration syndrome causes illness and death in up to 10% of newborns, according to Johns Hopkins Medicine.
Delivery teams are responsible for spotting signs of meconium aspiration syndrome and suctioning the baby’s airways. Clearing the airways ensures the baby doesn’t experience hypoxemia (lack of oxygen in the blood) or hypoxia (lack of oxygen in the tissues).
Depending on the severity of the baby’s breathing difficulties, the pediatrics team may also have to use mechanical ventilation or a breathing machine to keep the baby’s lungs inflated. Failure to do so could be a sign of medical negligence.
If your child developed severe meconium aspiration syndrome and suffered life-altering injuries as a result of negligence, you may be able to take legal action by filing a medical malpractice claim.
Get a free legal consultation to find out if you can get connected with one of the nation’s best birth injury firms.
A free case review is the first step in pursuing compensation for you and your family.
Filing a Meconium Aspiration Syndrome Lawsuit
If your child was harmed due to your obstetrician’s failure to diagnose or treat meconium aspiration syndrome in time, you may be able to take legal action.
Filing a birth injury lawsuit may allow you to recover compensation for:
- Diminished quality of life for your child
- Loss of income from missing work
- Medical expenses and hospital bills
- Pain and suffering
If your child has a birth injury caused by severe MAS, reach out to the Birth Injury Justice Center. We may be able to help you get justice and financial compensation.
Call (800) 914-1562 or fill out our online form for a free case review.
Meconium Aspiration Syndrome Causes FAQs
Who is at risk for meconium aspiration syndrome?
The main risk factors that lead to meconium aspiration syndrome causes are fetal distress and fetal heart rate irregularities.
What causes a baby to swallow meconium?
A baby may swallow meconium when they are stressed due to a decrease in blood and oxygen. Other causes of fetal distress include health issues of the mother, prolonged childbirth, and post-term delivery.
What causes meconium in amniotic fluid?
When babies are under stress due to a decrease in oxygen and blood supply, they may pass meconium while still in the womb. This causes meconium to mix with the amniotic fluid.
What causes a baby to swallow meconium?
When meconium mixes into the amniotic fluid, a baby is at risk for swallowing it when they take their first breaths during delivery. You may be able to sue for birth injuries caused by your baby swallowing meconium if medical negligence is to blame. See if you can connect with an experienced birth injury lawyer to learn more about your legal options.