Obstetrical Sonography II Lecture 17 Hydrops Fetalis hhholdorf

Outline Hydrops Fetalis Edema Robert’s Sign Spaulding Sign Immune Vs. Non-Immune Hydrops Rh Disease Middle Cerebral Artery PUBS ERYTHROBLASTOSIS FETALIS Non-Immune Hydrops TORCH Infections

Hydrops Fetalis A condition in the fetus characterized by an accumulation of fluid or edema in at least 2 fetal compartments: (i. e. , abdomen, lungs, heart muscle). Subcutaneous tissue/scalp pleura (pleural effusion) pericardium (pericardial effusion) Abdomen (ascites) OR Skin edema and fluid in ONE body cavity.

Hydrops fetalis is a condition in the fetus characterized by an accumulation of fluid, or edema, in at least two fetal compartments, including the subcutaneous tissue, pleura, pericardium, or in the abdomen, which is also known as ascites. The 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 the insatiable demand for an unusually high amount of blood flow. Hydrops fetalis (ie, fetal hydrops) may also be associated with polyhydramnios and placental edema.

Classification and causes 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 tumor or congenital cystic adenomatoid malformation increases the demand for blood flow.

Immune causes Rh disease is the major cause for immune hydrops fetalis; however, owing to preventative methods developed in the 1970 s Rh disease has markedly declined. Rh disease can be prevented by administration of anti-D Ig. G (Rho(D) Immune Globulin) injections to Rh. Dnegative mothers during pregnancy and/or within 72 hours of the delivery.

Non-Immune causes The non-immune form of hydrops fetalis has many causes including: Iron deficiency anemia Turner Syndrome Rarely, a tumor. The most common type of fetal tumor is a teratoma, particularly a Sacrococcygeal teratoma.

Treatment The treatment depends on the cause. Severely anemic fetuses can be treated with blood transfusions while still in the womb.

Background Hydrops fetalis has been a well-recognized fetal and neonatal condition throughout history. Until the latter half of the 20 th century, it was believed to be due to Rhesus (Rh) blood group isoimmunization of the fetus. More recent recognition of factors led to the use of the term non-immune hydrops to identify those cases in which the fetal disorder was caused by factors other than isoimmunization. In the 1970 s, the major cause of immune hydrops (ie, Rh D antigen) was conquered with the use of immunoglobulin (Ig) prophylaxis in at-risk mothers. This conquest was quickly followed by recognition that the non-immune causes of hydrops were, in fact, more common than had been suspected.

Pathophysiology Several hypotheses regarding the pathophysiologic events that lead to fetal hydrops have been suggested. The basic mechanism for the formation of fetal hydrops is an imbalance of interstitial fluid production and the lymphatic return. Fluid accumulation in the fetus can result from congestive heart failure, obstructed lymphatic flow, or decreased plasma osmotic pressure. The fetus is particularly susceptible to interstitial fluid accumulation because of its greater capillary permeability, compliant interstitial compartments, and vulnerability to venous pressure on lymphatic return.

Frequency/United States The precise incidence of hydrops fetalis is difficult to pinpoint, because many cases are not detected prior to intrauterine fetal death and some cases may resolve spontaneously in utero. The best estimate for how common hydrops fetalis is in the United States is approximately 1 in 600 to 1 in 4000 pregnancies. The incidence of immune hydrops has significantly decreased with the wide use of passive immunization using Rh immunoglobulin for Rh-negative mothers at 28 weeks' gestation.

Mortality/Morbidity The most important single factor of mortality is the cause of the hydrops. A significant proportion of these cases are caused or accompanied by multiple and complex congenital malformations of genetic and/or chromosomal origin, which by themselves are fatal at an early age. Many other causes are accompanied by masses or fluid accumulations, which compress the developing fetal lung and preclude its normal development. Thus, the presence or absence and potential prevention of pulmonary hypoplasia are of crucial importance.

Causes Hydrops fetalis is a nonspecific finding that is easily detected using prenatal sonography and may be associated with a wide range of associated abnormalities. However, despite extensive pre- and postnatal investigations, including postmortem pathological examination of the fetus, no definite cause can be found in about 26% of cases of nonimmune hydrops. Hydrops is an end-stage process for numerous fetal diseases. Causes can be mainly divided in 6 broad categories: cardiovascular, genetic abnormalities, intra-thoracic malformations, hematological disorders, infectious conditions, and idiopathic forms. The advent of routine Rh screening drastically reduced the occurrence of immune hydrops fetalis.

Sacrococcygeal teratoma is relatively common, accounting for a measurable proportion of incidents of fetal hydrops. Fetal imaging studies are the cornerstone for diagnosis and management of sacro-coccygeal teratoma. The fetus may bleed into the mother, and this hemorrhage may be severe enough to lead to fetal death or hydrops. Disruptions of the fetal-maternal circulation may be placental or related to tumors (choriocarcinoma, chorangioma), trauma, or partial placental abruption.

Thoracic and abdominal tumors are common causes of fetal hydrops. This association makes physiologic sense because the location and size of these masses are likely to obstruct the return of venous or lymphatic fluids to the heart. Tumor or mass causes of hydrops fetalis are as follows:

Intra-thoracic tumors or masses Pericardial teratoma Rhabdomyoma Mediastinal teratoma Abdominal tumors or masses Polycystic kidneys Neuroblastoma Ovarian cyst Other conditions Placental choriocarcinoma Placental chorangioma Cystic hygroma Intussusception Meconium peritonitis Sacrococcygeal teratoma

Cystic adenomatoid malformation of the lung may also lead to hydrops by mass compression of venous return. Because this condition is seldom associated with other malformations or with chromosomal abnormalities and because fetal surgical maneuvers have demonstrated considerable promise with some forms of the disorder, early and precise diagnosis using fetal imaging techniques is of critical importance. The fetal biophysical profile has been demonstrated to be abnormal in severe fetal hydrops.

Hydrops Fetalis

There can be skin edema and fluid in more than 2 body cavities in its most severe form. NOTE: normal skin thickness is 1 -2 mm ANASARCA-also known as extreme generalized edema is a medical condition characterized by widespread swelling of the skin due to effusion of fluid into the extracellular spaces. HALO sign refers to edema around the fetal head. Edema past the calvaria causes a double ring-very poor prognosis.

Edema High amounts of subcutaneous tissue which can lead to spontaneous abortion. Caused by heart failure : Heart is unable to work properly

Hydrops usually comes from ANEMIA: which is a low number of RBCs or Low hemoglobin in the blood The heart needs to pump a greater volume of blood to deliver the same amount of oxygen due to the low number of RBCs and hemoglobin

IN SUMMARY: Heart failure leads to a large Hydropic fetus which can lead to fetal death. Need to know the signs of fetal death: ROBERT’S and SPAULDING signs.

Robert’s Sign Robert's sign refers to the presence of a gas shadow within the heart or the greater vessels, in cases of fetal death. It is a rare sign caused by postmortem blood degeneration, usually seen 1 -2 days after death.

Robert’s Sign: Fetal demise

Spaulding Sign The Spalding sign refers the overlapping of the fetal skull bones caused by collapse of the fetal brain. This finding was originally described on abdominal radiographs and is indicative of fetal demise.

Anemia can be caused by IMMUNE or NON-IMMUNE circumstances

IMMNUE vs. NON-IMMUNE HYDROPS IMMUNE causes of Hydrops (ISO-IMMUNE Hydrops) Rh Disease: since the 1970 s, these cases have declined. Rh Disease can be prevented by giving the pregnant mother Anti-D Lg. G (Rho (D) immune globulin injections. AKA Rho. GAM These injections can be given during pregnancy and/or within 72 hours before delivery. A small percentage of mothers are still susceptible to Rh Disease even after the injections.

Rh disease:

Injections are not usually given before 28 weeks GA Injections can be given if mother has bleeding or a procedure such as an amniocentesis What is Rh Disease? AKA Rhesus isoimmunization or Rhesus Incompatibility. (Rhesus = Rhesus monkeys. Occurs only in some second or subsequent pregnancies of Rh negative women when the fetus’s father is Rh positive leading to an Rh+ pregnancy.

During birth, the mother may be exposed to the infant’s blood, and this causes the development of antibodies, which may affect the health or subsequent Rh+ pregnancies. Mild cases to moderate to severe cases. Severe cases lead to Erythroblastosis fetalis which causes Hydrops fetalis or fetal death.

Erythroblastosis Fetalis Hemolytic anemia in the fetus or neonate caused by transplancental transmission of maternal antibodies to fetal RBCs. The disorder usually results from incompatibility between maternal and fetal blood groups.

Doppler Evaluation MCA : The Middle Cerebral Artery Certain antigens cause significant anemia: this needs to be followed up with a Doppler study of the MCA of the fetus. Whenever you are given a choice as to which cerebral artery is to be assessed ALWAYS pick the middle cerebral artery (from the circle of Willis) USE the Pulsatility index (PI) and check this velocity with the charts: The higher the velocity, the more severe the anemia (more blood is needed to get normal amounts of oxygen due to severe anemia-lower RBCs After 34/35 weeks, the MCA is not accurate for mild anemia

The Circle of Willis showing the MCA

FETAL BLOOD SAMPLING/percutaneous Umbilical Blood Sampling (PUBS) is checked to see how severe the anemia and to see if a fetal transfusion is necessary or will be helpful.

PUBS

ERYTHROBLASTOSIS FETALIS Condition that develops in the fetus The Lg. G molecules (Anti-bodies from the placenta to the fetus…good stuff now replaced by bad stuff) produced by the mother passes through the placenta Some antibodies attack the RBCs in the fetal circulation The RBCs are broken down and the fetus develops anemia The Mother “Attacks” the fetus as though it were a foreign body.

ISOIMMUNIZATION: antibodies attack the fetal RBCs causing anemia which causes heart failure, which causes fetal edema, which when severe causes Hydrops fetalis.

NON-IMMUNE causes of fetal Hydrops There are many!!! CHF Maternal syphilis Turner syndrome (abnormality in which all or part of the female sex chromosome is missing Twin-to-twin transfusion syndrome in a monochorionic pregnancy (Hydrops affects the recipient twin) TORCH Infections …

TORCH infections are a group of congenitally acquired infections that cause significant morbidity and mortality in neonates. These infections are acquired by the mother and passed either transplacentally or during the birth process. While each infection is distinct, there are many similarities in how these infections present. It is important to consider TORCH infections whenever a neonate presents with any of the following: intrauterine growth restriction (IUGR) microcephaly intracranial calcifications conjunctivitis hearing loss rash hepatosplenomegaly thrombocytopenia.

TORCH Infections acquired in utero or during the birth process are a significant cause of fetal and neonatal mortality and an important contributor in early and later childhood morbidity. The infected newborn infant may show abnormal growth, developmental anomalies. The original concept f the TORCH perinatal infections was to group five infections with similar presentations, including rash and ocular findings.

TORCH Infections T = Toxoplasmosis O= Other R = Rubella C = Cytomegalovirus (CMV): Related to viruses that cause chickenpox and infectious mononucleosis (mono).

Indications of fetal demise Know Robert’s and Spaulding’s sign. NON-IMMUNE Hydrops can also be unrelated to anemia. Ex. a tumor such as CCAM can increase the demand for blood flow. This increased demand for cardiac output leads to heart failure and corresponding edema

Medical Care The diagnosis and management of hydrops fetalis continue to be challenges for perinatologists and neonatologists. Mortality rates are high, and treatment options are limited. The single most important factor to ensure proper treatment of the fetus with hydrops is a precise and detailed diagnosis. Until the underlying pathophysiology is clearly understood and the extent of the abnormalities leading the development of hydrops is completely defined, any attempt at treatment is futile and potentially harmful.

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