What is Meconium Plug Syndrome?
Meconium plug syndrome is a condition that can lead to a blockage in a newborn’s colon, or the large intestine. It’s relatively common, affecting about 1 in 500 newborns. Signs of this condition can look a lot like other types of blockages in the lower part of the intestine. In both cases, the baby might not be able to poop (pass meconium) in the first 24 to 48 hours after birth. But there are also many other conditions that can cause similar symptoms and appear the same on x-rays. This condition was first identified in 1956 and was named based on the fact that it’s caused by thick, sticky feces (meconium) that blocks the colon. There’s also a link between this syndrome and a particular disease called Hirschsprung’s disease, which affects the nerves controlling bowel movements. This link ranges between 3% to 38%.
What Causes Meconium Plug Syndrome?
The exact cause of meconium plug syndrome, a condition that leads to a blockage in a newborn’s intestines, is not entirely known. Most of the time, it happens on its own, without other health conditions.
However, sometimes it might be linked to other conditions, like:
* Premature birth
* Mothers with diabetes – both historic and pregnancy-induced diabetes
* Mothers who received a treatment known as magnesium sulfate for high blood pressure pregnancy complications or preterm labor
Also, according to a recent study, a connection with a treatment called magnesium tocolysis was found in 16% of cases, and a link with a rare disease called ‘Hirschsprung disease’ was seen in only about 3.2% of cases.
There is also a significant overlap of symptoms with a condition called “small left colon syndrome.” While the historical link between meconium plug syndrome and Hirschsprung disease has sometimes seemed unclear in new research, other studies found an association between the two conditions in 13 to 38% of cases.
Risk Factors and Frequency for Meconium Plug Syndrome
Meconium plug syndrome affects babies, and there’s no indication that one gender is more susceptible than the other. However, certain scenarios may increase the chances of a baby having the condition. For instance, the risk can be higher for:
- Premature infants, or babies born before they’re fully developed
- Babies born to diabetic mothers
- Moms who take drugs to prevent premature labor (called “tocolytic drugs.”)
This syndrome has also been seen in babies with Hirschsprung disease (a condition affecting the large intestine) and cystic fibrosis (a genetic disorder affecting the lungs and digestive system). Plus, babies with an increased risk of brain damage may face a higher incidence of meconium plug syndrome.
No reports suggest that this condition is more prevalent in a particular race, ethnic group, or region.
Signs and Symptoms of Meconium Plug Syndrome
Meconium Plug Syndrome is a condition that affects newborns. The main symptom is the newborn’s inability to pass meconium, the first type of stool, within 24 to 48 hours after birth. Following this, the baby may develop a swollen belly and start vomiting, which can sometimes include greenish bile. Often, these babies will have a softly swollen belly, which can even have detectable loops of intestine upon physical examination. If a nasogastric tube is used to remove stomach contents, it can contain bile – this indicates that there is a blockage in the lower part of the baby’s intestine.
Testing for Meconium Plug Syndrome
Abdominal x-rays, often called plain films, can be used to initially assess a child’s condition but they might not give a definitive diagnosis. These x-rays can show multiple air-fluid levels, which suggest a blockage, but it’s not typically possible to tell the difference between a small and large bowel obstruction from these images.
Occasionally, if there is air in the rectum, a shadow of the meconium – a newborn’s earliest bowel movements – might appear on the x-ray. The x-ray might also show small bowel gas mixed with colonic meconium which together, can give a grainy appearance, similar to a condition called necrotizing enterocolitis (NEC). However, if this grainy pattern appears within the first 12 hours, it’s most likely a different condition known as meconium plug syndrome, since NEC usually doesn’t develop until after 18 hours.
Unlike meconium ileus – another condition affecting a newborn’s bowels – you wouldn’t usually see a microcolon (an abnormally small colon) on x-rays for meconium plug syndrome.
A contrast enema, which uses a special dye to highlight the bowels on an x-ray, is usually the best test for diagnosis. Not only can it help to diagnose the condition, but it can also sometimes help to treat it. It’s typical to see a double-contrast impression on the x-ray, which looks like the meconium is against the wall of the colon. Usually, water-soluble contrast is used because barium contrast has a risk of causing an infection in the abdomen (peritonitis) if there’s a perforation (tear) during the procedure.
There are other tests that might be used to rule out other health conditions. A chloride sweat test might be used to rule out cystic fibrosis, a genetic condition that affects the lungs and digestive system. A suction rectal biopsy might be used to rule out Hirschsprung disease, which is a rare birth defect that causes blockage of the large intestine due to poor muscle movement in the bowel. In this test, a small piece of tissue is removed from the rectum and checked for missing nerve cells. It’s worth noting that there is a known relationship between meconium plug syndrome and Hirschsprung disease.
Finally, the baby’s blood electrolyte levels might be checked regularly to make sure they are safe while treatment with contrast enema agents is being done.
Treatment Options for Meconium Plug Syndrome
The treatment for this condition does not typically require surgery. The main goal is to stimulate the rectum or colon using an enema, which is a treatment that involves introducing a fluid into the rectum. Some patients may need multiple enemas, sometimes using a medication called acetylcysteine. Many patients will see immediate relief from their symptoms after the enema, including the passing of stool and a decrease in abdominal bloating.
If the patient still has not passed stool after 48 to 72 hours, surgical options must be considered. The surgeon usually performs a suction rectal biopsy, which is a procedure where a small piece of tissue is removed from the rectum for examination. If it is necessary to relieve pressure in the bowel, the surgeon can create a temporary ileostomy, which is an opening on the surface of the abdomen that allows waste to leave the body.
Different surgical approaches include the Mikulicz double-barreled ileostomy, a technique that has no risk of complications in the abdomen, while a skin bridge temporary ileostomy is seen as a more aesthetically pleasing alternative.
There are also more complex surgical options available. These include a distal ileostomy with a Bishop-Koop anastomosis, a technique that connects the end of the small intestine to a different part of it; this is also known as a distal chimney enterostomy. A similar procedure, known as the Santulli procedure, or a proximal chimney enterostomy is also an option. Usually, about ten days after the surgery, the ileostomies can be closed by performing an end-to-end anastomosis, which is a procedure joining two sections of intestine together.
What else can Meconium Plug Syndrome be?
Diagnosing meconium plug syndrome (MPS), a bowel obstruction in newborns, can be tough because many other conditions can look similar. The following conditions are ones to look out for:
- Hirschsprung disease: A condition where certain nerve cells are missing in the muscles of the baby’s colon.
- Malrotation: A condition where the intestine doesn’t develop into the right position in the abdomen.
- Meconium disease: A disorder where the baby’s first stool, or meconium, obstructs the intestines.
- Intestinal atresia: A condition where part of the intestine is narrow or missing.
It’s also essential to exclude some key conditions:
- Meconium ileus: This is serious as it blocks the small intestine and shrinks the colon’s width, resulting in a smaller colon. It can lead to severe complications like perforation (hole in the intestine), twisting of the small intestine, infection in the abdomen, and intestinal narrowing. Plus, it’s strongly linked with cystic fibrosis, a genetic disease causing lung infections and digestive problems.
- Small left colon syndrome (SLCS): This is a similar condition to MPS which causes temporary blockages in the colon. It’s called ‘small left colon’ because it typically changes the size of the colon near the spleen. SLCS mainly occurs in full-term babies, while MPS more often affects preterm babies. Both conditions usually resolve without treatment within 30 days.
- Hirschsprung disease: This can be identified with a rectal biopsy, while anorectal malformations can be diagnosed by physical exam.
- Malrotation and intestinal atresia: These can both be detected using an upper and lower gastrointestinal series, which are X-rays of the digestive tract.
What to expect with Meconium Plug Syndrome
Meconium Plug Syndrome typically has a very good outcome. A considerable number of cases can resolve on their own, and nearly all cases can be successfully treated with a special procedure called a water-soluble contrast enema, as long as there are no other underlying diseases. Simply put, this is a condition that can clear up on its own or with the help of a contrast enema.
It’s important to note that Meconium Plug Syndrome can be associated with other diseases like Hirschsprung’s disease and Cystic Fibrosis. However, the frequency of this syndrome varies widely in different studies. This variation could be due to different definitions used by different institutions or potential mistakes in coding the condition.
Possible Complications When Diagnosed with Meconium Plug Syndrome
Most cases are resolved with non-invasive treatment, and only a small few might require surgery, which typically has a good outcome. However, on rare occasions, complications might occur. These include a hole in the intestine (bowel perforation), tissue death in the intestine (necrosis of the bowel), and a potentially harmful condition known as meconium peritonitis, which results from meconium escaping into the peritoneal cavity.
Complications to look out for:
- Hole in the Intestine (Bowel Perforation)
- Tissue Death in the Intestine (Necrosis of the Bowel)
- Meconium Peritonitis
Preventing Meconium Plug Syndrome
Parents need to understand about the normal process of a newborn passing meconium, which is their first stool, and why it’s significant. Additionally, they should be aware of any possible warning flags like a swollen belly and the baby not accepting food.
