Chapter 24. Childhood diseases

Prenatal pathology

The progenesis period (gametogenesis) is the maturation period of gametes that are germ cells containing a half chromosome set compared to somatic cells. Diseases occurring in this period are called gametopathies. They can be inherited (hereditary mutations) or emerge as a result of mutations (sporadic mutations). Mutations may be at the level of genes, chromosomes, and genome. Patients have various manifestations in the structure of internal organs. Gametopathies lead to spontaneous termination of pregnancy, congenital malformations, hereditary diseases.

The blastogenesis period lasts from the 0 to day 15 of the intrauterine life. Diseases occurring during this period are called blastopathies. Blastopathies include double deformities: cranio-, thoraco- and ischiopagus (fig. 24.1), as well as impaired implantation of the ovum. Blastopathy manifests with severe deformities, many of which are fatal and lead to spontaneous termination of pregnancy.

Fig. 24.1. Blastopathy: a - craniothoracopagus; b - thoracoischiopagus

The period of embryogenesis lasts from day 16 to 75 of intrauterine d­evelopment. During this period, the morphogenesis of all main organs and systems of the human body takes place. Diseases arising during this period are called embryopathies. The effect of teratogenic factors during this period leads to focal or diffuse alteration changes, which subsequently contributes to the disruption of the organ formation. Embryopathies include gross systemic malformations: anencephaly, aplasia of individual organs, as well as teratomas (fig. 24.2). Embryopathies can lead to premature birth.

Fig. 24.2. Anencephaly

The fetogenesis phase is the last longest period, lasting from day 76 to 280 of the intrauterine development. Diseases of this period are called fetopathies (tissue malformations). They are characterized by generalized forms of infectious processes - multiple foci of alteration inflammation, pronounced hemorrhagic diathesis, restricted intrauterine growth - presence of islets of extramedullary hematopoiesis in full-term infants, delayed morphological maturation of organs, hypoplasia and dysplasia of organs and tissues (fig. 24.3).

The causes of prenatal anomalies are diverse: hereditary factors like mutations, maternal diseases (diabetes mellitus, anemia, kidney diseases, etc.), chemical and physical damaging factors, infections, obstetric-gynecological morbidity (gestosis, placental insufficiency), and immunological factors (erythroblastosis fetalis, etc.).

Fig. 24.3. Early fetopathy: high ventricular septal defect