Meconium Plug Syndrome - Causes, Diagnosis, and Treatment

Introduction

Meconium is the first formed stool of the newborn baby. Meconium appears greenish-black in color and consists of mucus, bile pigments, proteins, fats, and shred cells of the digestive tract. Meconium is usually passed within 24 to 48 hours after the baby's birth. However, babies suffering from meconium plug syndrome cannot pass the meconium within the first few hours of their lives. This condition should be swiftly treated to prevent further complications.

What Are the Causes of Meconium Plug Syndrome?

The exact cause of meconium plug syndrome is unknown, but it is believed that meconium plug is related to certain conditions of both mother and fetus.

1. Conditions of Fetus-Causing Meconium Plug Syndrome:

• Hirschsprung Disease:Hirschsprung disease occurs as a congenital disability in newborn babies. Babies who are affected with Hirschsprung disease have missing nerve cells in their large intestine (colon, rectum, and anus). Meconium formation occurs in the large intestine, and the nerve cells in the large intestine stimulate the muscles in the large intestine wall to pass the meconium into the anus. When the nerve cells are absent in the large intestine, muscle contraction movements fail. The formed meconium gets stuck in the large intestine without any movement. This causes constipation. In severe cases, the piled-up meconium causes bowel obstruction and blocks the large intestine.

• Preterm Babies: It refers to babies born 37 weeks prior to gestation are called preterm babies. Preterm babies have a higher risk of acquiring congenital defects like meconium plug syndrome.

• Low Birth Weight: WHO (World Health Organization) has defined low birth weight as weight at birth that is less than 2500 milligrams. Low birth weight babies can easily develop complications such as meconium plug syndromes.

• Cerebral Injury:Forceps delivery can cause cerebral compressions, which can lead to the damage of nerve cells and also nerve cell death in the brain. This results in a loss of coordination between muscles and nerves, leading to complications like meconium plug syndrome.

2. Conditions of Mother-Causing Meconium Plug Syndrome:

• Gestational Diabetes: When diabetes is diagnosed for the first time during the gestational period (pregnancy), it is called gestational diabetes. Mothers with gestational diabetes tend to develop meconium plug syndrome in their newborns.

• Chronic Diabetes: Uncontrolled or poor control of diabetes during pregnancy can cause birth defects like meconium plug syndrome.

• Magnesium Tocolysis: Tocolytic therapy is advised in some pregnant women to postpone labor. Magnesium tocolytic therapy prevents early contractions and prevents preterm complications in babies. Mothers treated with magnesium tocolytic treatment can pass on the magnesium sulfate (magnesium slows down the muscle contractions) to the fetus, leading to meconium plug syndrome.

How to Diagnose Meconium Plug Syndrome?

Diagnosis is made by following investigations:

• Contrast Enema: During the contrast enema, a thin tiny tube is inserted into the baby's large intestine (colon rectum and annus), and it is filled with safe, water-soluble contrast iodine or barium dye. Once the dye fills the large intestine, a special X-ray known as fluoroscopy is used to record pictures of the large intestine, which can lead to the conclusion of meconium plug syndrome.

• Chloride Sweat Test: This test is used to rule out cystic fibrosis in children, as cystic fibrosis can cause inspissated (thick) meconium, which causes blockage of the bowel.

• Rectal Suction Biopsy: Through this procedure, a small instrument is inserted into the large intestine, and a piece of muscle tissue from the large intestine is detached and taken out. This tissue sample is then transferred to the laboratory for investigation to check the presence of nerve cells.

• Serum Electrolytes: The electrolyte panel consists of a series of electrolyte tests. Sodium is one of the important electrolytes for nerve conduction which helps both the nerves and muscles to coordinate and function properly. Lack of sodium in the body leads to poor nerve signaling.

• Plain Radiograph: Plain abdominal films are used to detect abnormalities in the abdomen, small intestine, and large intestine. It might exhibit multiple dilated bowel loops, which are a nonspecific discovery. A minute change around the splenic flexure may be present.

How to Treat Meconium Plug Syndrome?

Generally, meconium plugs are treated by conventional methods, which use enemas to drain the poop contents in the large intestine. The following treatments can be suggested for the meconium plug:

• Enemas: Enema is a procedure in which a liquid or gas is administered via injections into the rectum to remove the undigested food material from the large intestine. The enemas constantly stimulate the large intestine to expel the poop. Usually, enema procedures are done occasionally, but some cases, like meconium plugs, require continuous enemas. After the enema, the baby should pass the stool within 2 to 3 days.

• Surgical Procedure: If the enema fails and the baby does not poop even after 72 hours, surgical procedures like ileostomy are done temporarily. An ileostomy is a procedure in which the damaged part of the ileum (the last part of the small intestine) is removed, and the open ends are diverted toward the skin on the abdomen. The undigested food material comes out of the abdominal opening. A temporary ileostomy is also indicated in the case of colon and rectal surgeries. During the healing period of the colon and rectum, ileostomy temporarily performs the large intestine functions.

• Double-Barreled Ileostomy: During the double-barreled ileostomy, the diseased and damaged parts of the small intestine are removed, and the two open ends are sutures on the skin on the stomach. These loose ends present on the abdominal wall are called stomas. One stoma helps in mucus drainage, and the other benefits drain out the waste material collected in the small intestine. Externally a bag is positioned onto the stomas to collect the drains (food and waste material). The external appearance of the collecting bag is the compromising part of the treatment.

What Is the Differential Diagnosis of Meconium Plug Syndrome?

• Bowel obstruction.

• Ileal atresia.

• Hirschsprung disease.

• Meconium ileus.

Conclusion

Meconium plug syndrome is a rare condition seen in infants. If the passage of meconium is not done within 24 hours, the doctors must perform diagnostic procedures to determine the cause. Most meconium plug syndromes are treated non-surgically, and only a few cases require surgical intervention. However, conventional and surgical treatments give a good prognosis and the best treatment outcomes.