Intrauterine infections

Intrauterine infections are pathological processes and diseases caused by antenatal and intranatal infection of the fetus. The true prevalence of intrauterine infections has not been established, however, according to generalized data, at least 10% of newborns are born with congenital infections. The relevance of the problem of intrauterine infections in pediatrics is due to high reproductive losses, early neonatal morbidity, leading to disability and postnatal death of children. The issues of prevention of intrauterine infections lie in the plane of consideration of obstetrics and gynecology , neonatology, and pediatrics.

Intrauterine infections develop as a result of infection of the fetus in the prenatal period or directly during childbirth. Usually, the source of intrauterine infection for a child is the mother, i.e., there is a vertical transmission mechanism, which in the antenatal period is realized by transplacental or ascending (through infected amniotic fluid) routes, and in the intranatal period by aspiration or contact routes.

Less commonly, iatrogenic infection of the fetus occurs during pregnancy when a woman undergoes invasive prenatal diagnosis ( amniocentesis , cordocentesis , chorionic villus biopsy ), the introduction of blood products to the fetus through the vessels of the umbilical cord (plasma, erythrocyte mass, immunoglobulins), etc.

In the antenatal period, infection of the fetus is usually associated with viral agents ( rubella , herpes , cytomegaly , hepatitis B and C , Coxsackie, HIV ) and intracellular pathogens (toxoplasmosis, mycoplasmosis ).

In the intranatal period, microbial contamination occurs more often, the nature and degree of which depends on the microbial landscape of the mother’s birth canal. Among bacterial agents, enterobacteria, group B streptococci, gonococci , Pseudomonas aeruginosa , Proteus, Klebsiella, etc. are the most common. The placental barrier is impenetrable to most bacteria and protozoa, however, if the placenta is damaged and placental insufficiency develops , antenatal microbial infection can occur (for example, by the causative agent of syphilis ). In addition, intranatal viral infection is not excluded.

Factors in the occurrence of intrauterine infections are a burdened obstetric and gynecological history of the mother ( nonspecific colpitis , endocervicitis , STDs, salpingoforitis ), an unfavorable course of pregnancy ( threat of interruption, preeclampsia , premature detachment of the placenta ) and infectious morbidity of the pregnant woman. The risk of developing a manifest form of intrauterine infection is significantly higher in premature babies and in the case when a woman becomes infected primarily during pregnancy.

The severity of clinical manifestations of intrauterine infection is affected by the timing of infection and the type of pathogen. So, if infection occurs in the first 8-10 weeks of embryogenesis, pregnancy usually ends in spontaneous miscarriage. Intrauterine infections that occur in the early fetal period (up to 12 weeks of gestation) can lead to stillbirth or the formation of gross malformations. Intrauterine infection of the fetus in the II and III trimester of pregnancy is manifested by damage to individual organs ( myocarditis , hepatitis , meningitis , meningoencephalitis ) or a generalized infection.

It is known that the severity of the manifestations of the infectious process in a pregnant woman and in a fetus may not coincide. The asymptomatic or oligosymptomatic course of infection in the mother can cause severe damage to the fetus, up to his death. This is due to the increased tropism of viral and microbial pathogens for embryonic tissues, mainly the central nervous system, heart, and organ of vision.

The etiological structure of intrauterine infections involves their division into:

• viral (viral hepatitis, herpes, rubella, SARS , cytomegaly, mumps , enterovirus infection )
• bacterial ( tuberculosis , syphilis, listeriosis , sepsis )
• parasitic and fungal (mycoplasmosis, toxoplasmosis, chlamydia , candidiasis , etc.)

To designate a group of the most common intrauterine infections, the abbreviation TORCH syndrome is used, which combines toxoplasmosis (toxoplasmosis), rubella (rubella), cytomegalovirus (cytomegalovirus), herpes (herpes simplex). The letter O (other) denotes other infections, including viral hepatitis, HIV infection, chicken pox , listeriosis, mycoplasmosis, syphilis, chlamydia, etc.).

The presence of intrauterine infection in a newborn may be suspected already during childbirth. In favor of intrauterine infection may indicate the outflow of turbid amniotic fluid contaminated with meconium and having an unpleasant odor, the state of the placenta (plethora, microthrobosis, micronecrosis). Children with intrauterine infection are often born in a state of asphyxia , with prenatal malnutrition , an enlarged liver, malformations or dysembryogenesis stigmas, microcephaly , hydrocephalus . From the first days of life, they have jaundice , elements of pyoderma , roseolous or vesicular rashes on the skin, fever, convulsive syndrome, respiratory and cardiovascular disorders.

The early neonatal period with intrauterine infections is often aggravated by interstitial pneumonia , omphalitis , myocarditis or carditis, anemia , keratoconjunctivitis , chorioretinitis , hemorrhagic syndrome, etc. An instrumental examination in newborns can reveal congenital cataracts , glaucoma , congenital heart defects , cysts and brain calcifications.

In the perinatal period, the child has frequent and profuse regurgitation, muscle hypotension, CNS depression syndrome, and gray skin. In the later stages, with a long incubation period of intrauterine infection, the development of late meningitis, encephalitis , osteomyelitis is possible .

Consider the manifestations of the main intrauterine infections that make up the TORCH syndrome.

Congenital toxoplasmosis

Intrauterine infection with the unicellular protozoan parasite Toxoplasma Gondii leads to severe fetal damage – developmental delay , congenital malformations of the brain, eyes, heart, and skeleton.

After birth in the acute period, intrauterine infection is manifested by fever, jaundice, edematous syndrome, exanthema, hemorrhages, diarrhea, convulsions, hepatosplenomegaly, myocarditis, nephritis, pneumonia. In subacute course, signs of meningitis or encephalitis dominate. With chronic persistence, hydrocephalus develops with microcephaly, iridocyclitis , strabismus , and atrophy of the optic nerves . Sometimes there are monosymptomatic and latent forms of intrauterine infection.

Late complications of congenital toxoplasmosis include oligophrenia , epilepsy , and blindness .

congenital rubella

Intrauterine infection occurs due to the rubella infection during pregnancy . The likelihood and consequences of infection of the fetus depend on the gestational age: in the first 8 weeks, the risk reaches 80%; The consequences of intrauterine infection can be spontaneous abortion , embryo- and fetopathy. In the II trimester, the risk of intrauterine infection is 10-20%, in the III – 3-8%.

Babies with intrauterine infection are usually born prematurely or with low birth weight. The neonatal period is characterized by hemorrhagic rash, prolonged jaundice.

The classic manifestations of congenital rubella are represented by Greg’s triad: eye damage (microphthalmia, cataract, glaucoma, chorioretinitis ), CHD ( open ductus arteriosus , ASD , VSD , pulmonary artery stenosis ), damage to the auditory nerve (sensoneural deafness). In the case of intrauterine infection in the second half of pregnancy, the child usually has retinopathy and deafness.

In addition to the main manifestations of congenital rubella, other anomalies may also be detected in a child: microcephaly, hydrocephalus, cleft palate , hepatitis, hepatosplenomegaly , malformations of the genitourinary system and skeleton. In the future, intrauterine infection reminds of itself by the child’s lag in physical development, mental retardation or mental retardation.

congenital cytomegaly

Intrauterine infection with cytomegalovirus infection can lead to local or generalized damage to many organs, immunodeficiency, purulent-septic complications. Congenital developmental defects usually include microcephaly, microgyria , microphthalmia, retinopathy, cataracts, congenital heart disease, etc. The neonatal period of congenital cytomegaly is complicated by jaundice, hemorrhagic syndrome, bilateral pneumonia, interstitial nephritis, and anemia.

Long-term effects of intrauterine infection include blindness, sensorineural deafness, encephalopathy, liver cirrhosis , pneumosclerosis .

congenital herpes infection

Intrauterine herpes infection can occur in a generalized (50%), neurological (20%), mucocutaneous (20%) form.

Generalized intrauterine congenital herpes infection occurs with severe toxicosis, respiratory distress syndrome , hepatomegaly , jaundice, pneumonia, thrombocytopenia , hemorrhagic syndrome. The neurological form of congenital herpes is clinically manifested by encephalitis and meningoencephalitis. Intrauterine herpes infection with the development of skin syndrome is accompanied by the appearance of a vesicular rash on the skin and mucous membranes, including internal organs. With the layering of a bacterial infection, neonatal sepsis develops .

Intrauterine herpes infection in a child can lead to the formation of malformations – microcephaly, retinopathy, limb hypoplasia (cortical dwarfism). Among the late complications of congenital herpes are encephalopathy , deafness, blindness, psychomotor retardation.

Currently, an urgent task is the prenatal diagnosis of intrauterine infections. For this purpose, in the early stages of pregnancy, smear microscopy, bacteriological culture from the vagina for flora, PCR examination of scrapings, and examination for the TORCH complex are performed. Pregnant women from the high-risk group for the development of intrauterine infection are indicated for invasive prenatal diagnosis (chorionic villus aspiration, amniocentesis with amniotic fluid examination, cordocentesis with cord blood examination).

It is possible to identify echographic markers of intrauterine infections using obstetric ultrasound . Indirect echographic signs of intrauterine infection include oligohydramnios or polyhydramnios; the presence of hyperechoic suspension in the amniotic fluid or amniotic bands ; chorionic villus hypoplasia, placentitis; premature aging of the placenta ; fetal edematous syndrome ( ascites , pericarditis , pleurisy ), hepatosplenomegaly, calcifications and malformations of internal organs, etc. In the process of Doppler examination of blood flow, violations of the fetal-placental blood flow are detected. Cardiotocography detects signsfetal hypoxia .

After the birth of a child, in order to reliably verify the etiology of intrauterine infection, microbiological (virological, bacteriological), molecular biological (DNA hybridization, PCR), serological (ELISA) examination methods are used. Histological examination of the placenta is of great diagnostic value.

According to indications, newborns with intrauterine infections on the first day of life should be examined by a pediatric neurologist , pediatric cardiologist , pediatric ophthalmologist , and other specialists. It is expedient to carry out EchoCG , neurosonography , ophthalmoscopy , hearing examination by the method of evoked otoacoustic emission .

General principles for the treatment of intrauterine infections involve immunotherapy, antiviral, antibacterial and post-syndromic therapy.

Immunotherapy includes the use of polyvalent and specific immunoglobulins, immunomodulators (interferons). Antiviral therapy of directed action is carried out mainly with acyclovir. For antimicrobial therapy of bacterial intrauterine infections, broad-spectrum antibiotics (cephalosporins, aminoglycosides, carbapenems) are used, and macrolides are used for mycoplasmal and chlamydial infections.

Posyndromic therapy of intrauterine infections is aimed at stopping individual manifestations of perinatal CNS damage, hemorrhagic syndrome, hepatitis, myocarditis, pneumonia, etc.

With generalized forms of intrauterine infections, mortality in the neonatal period reaches 80%. With local forms, serious damage to internal organs occurs ( cardiomyopathy , COPD , interstitial nephritis , chronic hepatitis , cirrhosis, etc.). In almost all cases, intrauterine infections lead to damage to the central nervous system.

Prevention of intrauterine infections consists in preconception preparation, treatment of STDs before pregnancy, exclusion of contact between a pregnant woman and infectious patients, and correction of a pregnancy management program for women at risk. Women who have not previously had rubella and have not received rubella vaccinations should be vaccinated no later than 3 months before the expected pregnancy. In some cases, intrauterine infections may be the basis for artificial termination of pregnancy .