Birth trauma of the newborn

Pneumopathies and respiratory distress syndrome

The main forms of pneumopathies include atelectasis, hyaline membrane disease, and edema-hemorrhagic syndrome.

Atelectasis (segmental and polysegmental) is characterized by the collapse of areas of pulmonary tissue. Notably, segmental forms are more commonly diagnosed in more mature infants.

Hyaline membrane disease is a pathological process in which a lumpy or homogeneous hyaline-like substance is deposited on the inner surface of the alveoli, respiratory bronchioles, and alveolar ducts. The disease is typical for immature and premature infants. The pathogenesis is based on pulmonary immaturity, surfactant synthesis disruption, hypoxia, hypercapnia, as well as coagulation failures and increased capillary permeability. Clinically, respiratory disorders develop progressively 1–2 hours after birth. Radiography reveals a specific nodular-reticular net, and in severe cases, homogeneous opacities through which the contours of the diaphragm, heart, and large vessels are indistinguishable.

Edema-hemorrhagic syndrome is considered one of the most severe forms of pneumopathies. Due to hypoxemia, acidosis, hypoproteinemia, hyperprogesteronemia, or stagnant plethora (in heart failure), capillary permeability increases sharply, leading to excessive fluid accumulation in the lungs. The clinical picture includes pronounced dyspnea with retraction of compliant areas of the chest wall, apnea, cyanosis, pallor, arrhythmia, and neurological deficits (seizures, swallowing and sucking disorders). Radiologically, there is a decrease in air content (especially in the root zones) and blurring of structures, up to total homogeneous opacification of the lung.

Aspiration syndrome and neonatal pneumonia

Aspiration syndrome develops more frequently in full-term and large infants. Massive aspiration leads to obstruction of the bronchial lumen, which triggers severe asphyxia immediately after birth. Less intensive aspiration triggers a macrophage reaction of the epithelium and aseptic leukocytic alveolitis. X-rays visualize confluent foci of consolidation resembling inflammatory infiltration and obstructive atelectasis. Infection of aspiration masses frequently leads to bacterial pneumonia.

Neonatal pneumonia is divided into intrauterine and postnatal. True intrauterine forms are rare and usually associated with specific infections (cytomegaly, listeriosis). Postnatal forms develop significantly more often, especially against the background of pre-existing pneumopathies.

The etiology of pneumonia is predominantly mixed (viruses, fungi, mycoplasmas, pneumocystis), while the role of Gram-negative bacteria (Escherichia coli, Klebsiella, Proteus) is steadily growing. The infection enters transplacentally, via airborne droplets, or through the aspiration of amniotic fluid. In the pathogenesis, a vicious circle is formed: respiratory failure causes homeostasis shifts (hypoxia, hypercapnia, acidosis), which, in turn, critically exacerbate external respiration dysfunction.

Severity assessment and treatment principles

To objectively assess the degree of respiratory failure, determine the dynamics of disorders, and establish the scope of respiratory support, the Silverman score is used:

• 1–3 points: mild degree;
• 4–5 points: moderate degree;
• 6 points or more: severe degree.

Therapeutic measures start upon the appearance of the first symptoms. Oxygen therapy (in an incubator, via mask, or nasal cannula) is performed under strict control of the blood gas composition for adequate tissue oxygen supply. If oxygen therapy is ineffective and severe respiratory distress syndrome is present, tracheal intubation and mechanical ventilation are indicated. Medical support includes infusion therapy and administration of surfactant preparations. For the prevention of respiratory distress syndrome, pregnant women at risk of preterm labor are prescribed glucocorticoid drugs.

Congenital anomalies and chromosomal diseases

Congenital malformations are structural or functional pathologies resulting from gametopathies, blastopathies, embryopathies, and fetopathies. In the structure of causes, 30–40% are multifactorial anomalies (a combination of genetic and exogenous factors), 25–30% are genetically determined, 2–5% are exogenous (teratogenic), and up to 50% of cases have an unclear etiology.

Chromosomal diseases are the most common, based on mutations (changes in the number or structure of chromosomes) and polyploidy. Severe forms usually lead to spontaneous abortion in the first trimester.

1. Down syndrome (trisomy 21): occurs with a frequency of 1:600. In 94–95% of cases, this is a simple complete trisomy due to non-disjunction of chromosomes in meiosis. The phenotype includes an upward slant of the eyes, a flat face, epicanthus, a large protruding tongue, brachycephaly, and excess skin on the neck. Concomitant heart and gastrointestinal malformations, clinodactyly, a single transverse palmar crease, and developmental delay are characteristic.
2. Patau syndrome (trisomy 13): occurs less frequently (1:7000). In 80–85% of cases, this is a simple trisomy, with the rest attributable to Robertsonian translocations. The syndrome is accompanied by severe malformations of the brain, eyes, and skull. Cleft lip or palate (cheiloschisis, palatoschisis), microphthalmia, polydactyly, and congenital heart defects are typical.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Mechanisms of embryonic dysmorphogenesis development in gene mutations.
• The role of Robertsonian translocations in the inheritance of Patau syndrome.
• The effect of hyperprogesteronemia on pulmonary capillary permeability.
• Specific congenital infections (listeriosis, cytomegaly) in the etiology of pneumonias.
• Pathogenesis of the macrophage reaction in amniotic fluid aspiration.

Other topics in the "Obstetrics" section

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