Traditional indicators, such as a newborn's weight and height, are still utilized since they can approximate a child's future risk of getting any disease. However, the implications of these indicators on the child's future adult development remain uncertain; for example, infants who are overweight or short in stature may suffer insulin insufficiency at birth, increasing their chances of developing diabetes as adults1.

In fact, a mother's nutritional and hormonal state during pregnancy (including the postpartum period) can affect various aspects of his or her child's adult life, including the development of metabolic diseases like obesity, high blood pressure, hypercholesterolemia, hyperlipidemia, and so on2.

One method for diagnosing potential abnormalities in neonates is the detection of acidosis, which is a pH shift in the umbilical cord that suggests hypoxic stress in the developing baby3. The cord's low pH was shown to be independent of the existence of hypoxic ischemic lesions4.

The majority of the diagnostic procedures done on babies in the first few days after delivery are called neonatal screening (NS)5. On this test, a heel pinch is used to draw blood, which is then stored as a drop of dried blood (DBS) on neonatal detection cards (NSCs). This makes it possible to diagnose diseases including cystic fibers, phenylcetonuria, biotinidase deficiency, galactosemia, central congenital hypothyroidism, primary congenital hypothyroidism, and congenital adrenal hyperplasia6.

On the other hand, despite improvements in neonatal care and scientific knowledge, neonates may also die from sepsis, suffer significant impairment, or undergo neurological deterioration a condition that affects 4 out of 10 newborns on average in affluent nations78.

It's important to remember that neonatal sepsis, along with other clinical symptoms and hemodynamic alterations that raise newborn morbidity and mortality, is a systemic inflammation brought on by bacteria, viruses, or fungi7. Neonatal sepsis still has few pharmacological therapy options, most of which center on supportive care and early antibiotic administration. Various clinical and blood markers have been examined in this context in order to identify sepsis and characterize its severity and cause9.

On the other hand, neonates with neonatal pneumonia (NE) are among the most common causes of death in neonatal intensive care unit (NICU) because of the high chance that they will experience neurological difficulties and disabilities throughout their lifetimes10.

In parallel, microRNA was discovered during research on the nematode Caenorhabditis elegans11, and their use as a diagnostic tool has only recently begun because they are useful for determining the onset and progression of disease due to their high specificity for different tissue or cell types. MicroRNAs have been shown to be sensitive, with levels fluctuating in response to treatment or the rate at which the disease advances12.

There is a growing focus on the application of microRNA-based biomarkers for real-time therapeutic decision-making in the context of neonatal sepsis and other disorders affecting neonates10. The primary benefit is that the patient can receive highly accurate disease diagnosis and surveillance with the least invasive techniques.

For example, Dakroub et al.13 discovered ten microRNAs in the group of newborns with NE when compared to healthy controls, where microARNs in these neonates experience significant alterations within a few hours of birth. Additionally, research has been done on microRNAs as early indicators of newborn sepsis10.

Another example of how microRNAs benefit newborns is the range of macronutrients available in breast milk, which includes lactose, oligosaccharides, lipids, proteins, and nonprotein nitrogen. Breast milk is one of the most microRNA-rich biological fluids, with over 1400 distinct microRNAs accounting for approximately 25% of the total nitrogen in milk14. 

Two more examples. Ibrahim et al.'s study15, for instance, children with asthma exhibit reduced expression of miRNA-196a-2 and elevated serum levels of Annexin A1 (ANXA1, an essential anti-inflammatory mediator that may be crucial in bronchial asthma), indicating their potential as diagnostic biomarkers and therapeutic targets as well as their involvement in the etiology of asthma. Finally, MicroRNAs' function in controlling the expression of sirtuin 1 (a potential target for slowing down aging) 16171819.