| Hydrops fetalis | |
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| An ultrasound showing a fetus with hydrops fetalis | |
| Specialty | Obstetrics and gynaecology, hematology, immunology  |
Hydrops fetalis or hydrops foetalis is a condition in the fetus characterized by an accumulation of fluid, or edema, in at least two fetal compartments. [1] [2] By comparison, hydrops allantois or hydrops amnion is an accumulation of excessive fluid in the allantoic or amniotic space, respectively. [3]
Locations can include the subcutaneous tissue on the scalp, the pleura (pleural effusion), the pericardium (pericardial effusion) and the abdomen (ascites). Edema is usually seen in the fetal subcutaneous tissue, sometimes leading to spontaneous abortion. It is a prenatal form of heart failure, in which the heart is unable to satisfy demand (in most cases abnormally high) for blood flow.[ citation needed ]
Hydrops fetalis usually stems from fetal anemia, when the heart needs to pump a much greater volume of blood to deliver the same amount of oxygen. This anemia can have either an immune or non-immune cause. Non-immune hydrops can also be unrelated to anemia, for example if a fetal tumor or congenital cystic adenomatoid malformation increases the demand for blood flow. [5] The increased demand for cardiac output leads to heart failure, and corresponding edema.
Erythroblastosis fetalis, also known as Rh disease, is the only immune cause of hydrops fetalis. Rh disease is a hemolytic disease of newborns. Pregnant mothers do not always have the same blood type as their child. During birth or throughout the pregnancy, the mother may be exposed to the infant's blood. In the event of a pregnancy where the fetus has the Rh-D blood antigen and the mother does not, the mother's immune system will respond to the red blood cells as foreign and create antibodies against the Rh-D antigen on the fetal blood cells. Rh disease develops in the event of a second pregnancy where the mother's immune system launches an attack, via IgG, against the infant's Rh-D positive blood cells. The immune response results in hemolysis of fetal red blood cells causing severe anemia.[ citation needed ]
Hemolysis caused by the Rh incompatibility, causes extramedullary hematopoiesis in the fetal liver and bone marrow. [6] The push to make more erythroblasts to help compensate with the hemolysis over works the liver causing hepatomegaly. The resulting liver dysfunction decreases albumin output which in turn decreases oncotic pressure. Consequentially, the decrease in pressure results in overall peripheral edema and ascites.[ citation needed ]
Rh disease is currently an uncommon cause of immune-mediated hydrops fetalis. Due to preventative methods developed in the 1970s, the incidence of Rh disease has markedly declined. Rh disease can be prevented by administration of anti-D IgG (Rho(D) Immune Globulin) injections to RhD-negative mothers during pregnancy and/or within 72 hours of the delivery. However, a small percentage of pregnant mothers are still susceptible to Rh disease even after receiving anti-D IgG (Rho(D) Immune Globulin).[ citation needed ]
Severe anemia leads to hyperdynamic circulation, which means high-output cardiac failure causes the blood to circulate rapidly. The excessive pumping of blood causes the left side of the heart to fail leading to pulmonary edema. The build up of fluid in the lungs increases the pressure in the lungs leading to vasoconstriction. The coupled vasoconstriction and pulmonary hypertension causes the right side of the heart to fail which in turn, increases the venous hydrostatic pressure in the body. The summation of these effects ultimately leads to peripheral edema and ascites. All in all, the left side failure of the heart will lead to pulmonary edema whereas right side failure will lead to peripheral edema and ascites. The non-immune form of hydrops fetalis has many causes including: [7] [8]
Hydrops fetalis can be diagnosed and monitored by ultrasound scans. [1] An official diagnosis is made by identifying excess serous fluid in at least one space (ascites, pleural effusion, of pericardial effusion) accompanied by skin edema (greater than 5 mm thick). A diagnosis can also be made by identifying excess serous fluid in two potential spaces without accompanying edema. Prenatal ultrasound scanning enables early recognition of hydrops fetalis and has been enhanced with the introduction of MCA Doppler. [7]
The treatment depends on the cause and stage of the pregnancy. [7]
Amniocentesis is a medical procedure used primarily in the prenatal diagnosis of genetic conditions. It has other uses such as in the assessment of infection and fetal lung maturity. Prenatal diagnostic testing, which includes amniocentesis, is necessary to conclusively diagnose the majority of genetic disorders, with amniocentesis being the gold-standard procedure after 15 weeks' gestation.
Erythema infectiosum, fifth disease, or slapped cheek syndrome is one of several possible manifestations of infection by parvovirus B19. Fifth disease typically presents as a rash and is more common in children. While parvovirus B19 can affect humans of all ages, only two out of ten individuals will present with physical symptoms.
Rh disease is a type of hemolytic disease of the fetus and newborn (HDFN). HDFN due to anti-D antibodies is the proper and currently used name for this disease as the Rh blood group system actually has more than 50 antigens and not only the D-antigen. The term "Rh Disease" is commonly used to refer to HDFN due to anti-D antibodies, and prior to the discovery of anti-Rho(D) immune globulin, it was the most common type of HDFN. The disease ranges from mild to severe, and occurs in the second or subsequent pregnancies of Rh-D negative women when the biologic father is Rh-D positive.
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis foetalis, is an alloimmune condition that develops in a fetus at or around birth, when the IgG molecules produced by the mother pass through the placenta. Among these antibodies are some which attack antigens on the red blood cells in the fetal circulation, breaking down and destroying the cells. The fetus can develop reticulocytosis and anemia. The intensity of this fetal disease ranges from mild to very severe, and fetal death from heart failure can occur. When the disease is moderate or severe, many erythroblasts are present in the fetal blood, earning these forms of the disease the name erythroblastosis fetalis.
Complications of pregnancy are health problems that are related to, or arise during pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal disorders. While some complications improve or are fully resolved after pregnancy, some may lead to lasting effects, morbidity, or in the most severe cases, maternal or fetal mortality.
A vertically transmitted infection is an infection caused by pathogenic bacteria or viruses that use mother-to-child transmission, that is, transmission directly from the mother to an embryo, fetus, or baby during pregnancy or childbirth. It can occur when the mother has a pre-existing disease or becomes infected during pregnancy. Nutritional deficiencies may exacerbate the risks of perinatal infections. Vertical transmission is important for the mathematical modelling of infectious diseases, especially for diseases of animals with large litter sizes, as it causes a wave of new infectious individuals.
Hemolytic disease of the newborn (anti-Kell1) is the second most common cause of severe hemolytic disease of the newborn (HDN) after Rh disease. Anti-Kell1 is becoming relatively more important as prevention of Rh disease is also becoming more effective.
Hemolytic disease of the newborn (anti-Rhc) can range from a mild to a severe disease. It is the third most common cause of severe HDN. Rh disease is the most common and hemolytic disease of the newborn (anti-Kell) is the second most common cause of severe HDN. It occurs more commonly in women who are Rh D negative.
Mirror syndrome or triple edema or Ballantyne syndrome is a rare disorder affecting pregnant individuals. It describes the unusual association of fetal and placental hydrops with maternal preeclampsia.
Hemoglobin Barts, abbreviated Hb Barts, is an abnormal type of hemoglobin that consists of four gamma globins. It is moderately insoluble, and therefore accumulates in the red blood cells. Hb Barts has an extremely high affinity for oxygen, so it cannot release oxygen to the tissue. Therefore, this makes it an inefficient oxygen carrier. As an embryo develops, it begins to produce alpha-globins at weeks 5–6 of development. When both of the HBA1 and HBA2 genes which code for alpha globins becomes dysfunctional, the affected fetuses will have difficulty in synthesizing a functional hemoglobin. As a result, gamma chains will accumulate and form four gamma globins. These gamma globins bind to form hemoglobin Barts. It is produced in the disease alpha-thalassemia and in the most severe of cases, it is the only form of hemoglobin in circulation. In this situation, a fetus will develop hydrops fetalis and normally die before or shortly after birth, unless intrauterine blood transfusion is performed.
Maternal–fetal medicine (MFM), also known as perinatology, is a branch of medicine that focuses on managing health concerns of the mother and fetus prior to, during, and shortly after pregnancy.
Hemolytic disease of the newborn (anti-RhE) is caused by the anti-RhE antibody of the Rh blood group system. The anti-RhE antibody can be naturally occurring, or arise following immune sensitization after a blood transfusion or pregnancy.
Fetal echocardiography, or Fetal echocardiogram, is the name of the test used to diagnose cardiac conditions in the fetal stage. Cardiac defects are amongst the most common birth defects. Their diagnosis is important in the fetal stage as it might help provide an opportunity to plan and manage the baby as and when the baby is born. Not all pregnancies need to undergo fetal echo.
Pulmonary hypoplasia is incomplete development of the lungs, resulting in an abnormally low number or small size of bronchopulmonary segments or alveoli. A congenital malformation, it most often occurs secondary to other fetal abnormalities that interfere with normal development of the lungs. Primary (idiopathic) pulmonary hypoplasia is rare and usually not associated with other maternal or fetal abnormalities.
Congenital pulmonary airway malformation (CPAM), formerly known as congenital cystic adenomatoid malformation (CCAM), is a congenital disorder of the lung similar to bronchopulmonary sequestration. In CPAM, usually an entire lobe of lung is replaced by a non-working cystic piece of abnormal lung tissue. This abnormal tissue will never function as normal lung tissue. The underlying cause for CPAM is unknown. It occurs in approximately 1 in every 30,000 pregnancies.
An Intrauterine transfusion (IUT) is a procedure that provides blood to a fetus, most commonly through the umbilical cord. It is used in cases of severe fetal anemia, such as when fetal red blood cells are being destroyed by maternal antibodies. IUTs are performed by perinatologists at hospitals or specialized centers.
The congenital heart block (CHB) is the heart block that is diagnosed in fetus or within the first 28 days after birth, some studies also include the diagnosis during early childhood to the definition of CHB. It refers to the disorder in the electrical conduction system within the heart muscle, which leads to the failure in pumping the blood efficiently into the aorta and the pulmonary trunk. The result of CHB can be first, second, or third-degree (complete) atrioventricular block in which no electric signals move from the atrium to the ventricles
Transfusion-dependent anemia is a form of anemia characterized by the need for continuous blood transfusion. It is a condition that results from various diseases, and is associated with decreased survival rates. Regular transfusion is required to reduce the symptoms of anemia by increasing functional red blood cells and hemoglobin count. Symptoms may vary based on the severity of the condition and the most common symptom is fatigue. Various diseases can lead to transfusion-dependent anemia, most notably myelodysplastic syndromes (MDS) and thalassemia. Due to the number of diseases that can cause transfusion-dependent anemia, diagnosing it is more complicated. Transfusion dependence occurs when an average of more than 2 units of blood transfused every 28 days is required over a period of at least 3 months. Myelodysplastic syndromes is often only diagnosed when patients become anemic, and transfusion-dependent thalassemia is diagnosed based on gene mutations. Screening for heterozygosity in the thalassemia gene is an option for early detection.