Hydrops fetalis, characterized by fluid accumulation in fetal tissues and body cavities, is a nonspecific finding appeared in many different ways.
Hydrops occurring in patients with Rh incompatibility/Infected rh is called “Immune Hydrops Fetalis”,however hydrops arising out of fetal or maternal causes is called “nonimmune hydrops fetalis”.
85% of all cases of hydrops are nonimmune hydrops fetalis.
Pathogenesis:
Three main factors play a role in the pathogenesis of hydrops fetalis.
1. Factors affecting the lymphatic flow
2. Factors that may increase intravascular hydrostatic pressure.
3. Factors that reduce intravascular osmotic pressure.
Disruption of lymphatic flow, results in fetal edema caused by accumulation of fluid. Some congenital heart defects and rhythm disfunctions, prolonged circulation time, venous distension, hepatomegaly, edema, and poor perfusion of the tissues may create hemodynamic instability. Venous pressure, may lead to prevention of lymphatic flow passing through the lymphatic pressure.
Fetal hipoproteinem may cause albumin synthesis deterioration in the liver or loss of plasma protein secondarily. If hypoproteinemia develops further, relative decrease of protein would be higher than the decrease in plasma interstitium. With the initial distribution of proteins, transcapillary colloid osmotic pressure is maintained. When a decrease in interstitial colloid osmotic pressure can not compensate the decrease in plasma osmotic pressure, net infiltration of fluids and interstitial fluid volume increases, namely edema occurs.
Protein synthesis in hepatocytes is reduced as a result of disruption of protein synthesis due to hypoxia or the transformation of liver into erythropoietic tissues. Congestive heart failure can also cause malfunction and hepatomegaly. Genetic metabolic diseases and intrauterine infections are other conditions that cause the liver damage and hypoproteinaemia.
The etiology of nonimmune hydrops fetalis:
Many fetal and maternal pathological conditions play a role in the etiology of nonimmune hydrops fetalis. Chromosomal abnormalities, fetal abnormalities, metabolic disorders, intrauterine infections, feto-maternal or twin-twin transfusion, thalassemia, arterio-venous shunt, and anomalies such as gastrointestinal, cardiac and pulmonary pathology, are among the other etiological factors.
Down syndrome, trisomic Turner syndrome, and other chromosomal abnormalities such as triploidy occur with the hydrops fetalis tables. Hydrops is not a frequent finding in metabolic diseases, and have a poor prognosis in patients with it.
Twin-to-twin transfusion in twin pregnancies due to fetal structural anomalies or placental vascular anomalies may cause hydrops fetalis. Hydrops fetalis is often arisen from the receiver fetus, however it can also be seen in the transmitter fetus.
Adenoid cystic tumors of the lung impair venous system by increasing intrathoracic pressure. Thus, they initially cause pleural effusion, and hydrops afterwards.
Toxoplasmosis, CMV, parvovirus, syphilis, human leptospirosis, Chagas disease, and diseases such as congenital hepatitis are seen with nonimmune hydrops.
Diagnosis:
The hydrops fetalis is diagnosed by routinely performed ultrasonography during antenatal follow-up. The ultrasonographic diagnosis of hydrops fetalis, regardless of the etiology, is the skin thickness to be more than 5.
Treatment and Handling:
The basic rule in the treatment of fetal hydrops is the early diagnosis and the treatment of the underlying etiological factors.
· The first steps needed to be taken after the detection of hydropic fetus are the maternal complete blood count, Kleihauer-Betke test, attaining the blood group and Rh, indirect Coombs test (rh-negative cases), TORCH titers, parvovirus B 19, and serological studies for syphilis, G6PDH deficiency and screening for hemoglobinopathies.
· Since, it is reported that chromosomal abnormalities detected in some of the patients with nonimmune hydrops, amniocentesis, placental biopsy or cordocentesis should be performed for karyotype determination method.
Fetal blood sampling in the same time, anemia, hemoglobinopathies, such as thrombocytopenia or combined etiologic factors can be determined.
The therapeutic abortion in cases of chromosomal abnormality is detected.
Approach to cardiovascular pathologies related cases, termination of pregnancy, premature birth until postnatal care and variable operations.
Intrauterine infection with parvovirus B19 is composed of fetal anemia. Fetal anemia and hydrops due to intrauterine fetal blood transfusion can be prevented.
Among the factors considered severe maternal diabetes, anemia, and hypoproteinemia, the antenatal follow up and treatment prevented the development of hydrops should be avoided.
Yorum Yok