Module 15 : Hydrops Flashcards
what is the definition of hydrops
- abnormal accumulation of serous fluid in at least 2 body cavities or tissue
is serous fluid amniotic fluid
- no
what are 4 examples of collections of fluid in fetus
- pleural effusion
- abdominal ascites
- pericardial effusion
- edema
what are the two classifications of hydrops and what are they based on
- based on etiology
- immune vs non immune
is hydrops common or rare
- common
- each specific etiology that causes it is rare
when is hydrops usually seen in fetus
- terminal stage for many conditions
- signifies fetal decomposition
how long does it take for demise to occur when decomposition starts in fetus
- progression of hydrops is rapid and demise can occur within 24-48 hours
why is investigation important with hydrops
- important for management and future counselling
what are 2 important aspects of the investigation
- ultrasound
- fetal blood sampling
7 sonographic features of hydrops
- ascites
- pleural effusion
- pericardial effusion
- subcutaneous edema
- placental edema
- arterial or venous doppler abnormalities
- low BPP scores
what is ascites
- fluid collecting in the fetal abdomen
where might we see the fluid first with ascites and why
- pelvis
- gravity = most dependent
what might ascites cause in males
- fluid tracks down into scrotum causing hydrocele
what is pseudoascites
< 2mm hypo echoic ring around muscular layer of the abdominal wall
- change probe angle to assess if its really free fluid
what is a pleural effusion
- fluid in plural space around the lungs
what does the pleural effusion cause in regards to pressure
- increase in pleural effusion»_space; increase in pressure on the mediastinum, thoracic vasculature and heart
what three things pleural effusion cause
- upper body edema
- poly
- pulmonary hypoplasia
where can subcutaneous edema be located
- general, local
- limited to the upper or lower body depending on eitology
what is anasarca
- general edema
where is edema first seen
- fetal scalp and face
- then abdomen and limbs
what is placental edema a sign of
- late sign of hydrops
what does placental edema look like
- ground glass appearance and > 4cm thick
what will the placenta look like if the hydrops is of fetal etiology
- whole placenta should be thick
what will placenta look like if hydrops is due to placenta vascular malformation
- only that part of the placenta looks hydropic
what is the pattern of immune hydrops
- 1st ascites
- 2nd edema
- 3rd pleural and pericardial effusions
what is the pattern of hydrops with thoracic abnormalities
- chylothorax and heart abnormalities
- pleural and pericardial effusions usually occur first
what is chyle
- milky fluid drom food is taken up during digestion
- consists of lymph fluid
what are two other names for immune hydrops
- alloimmune hydrops
- erythroblastosis fetalis
what causes immune hydrops
- when rhesus sensitized mother has antibodies to fetal red blood cells
- mom is Rh -
- hemolysis occurs when maternal immunoglobulin antibodies cross the placenta and attack antigen positive fetal red cells
what is hemolysis
- separation of the hemoglobin from the red cells and is then found in plasma
what is Rhesus factor
- majority have red blood cell protein called Rhesus factor (Rh+)
- minority lack the protein (Rh-)
- immune hydrops is due to anti D antibodies
what does the destruction of RBCs cause in the fetal
- anemia
- hepatosplenomegaly
- erythroblastosis fetalis
what is erythroblastosis fetalis
- outpouring of many immature red blood cells
- these immatures RBC do not support or carry oxygen well
what does erythroblastosis fetalis cause
1 = tissue hypoxia
+ immature RBC can carry oxygen to tissues
2 = hydrops
+ fluid leaks out of cells causing hydrops
3 = cardiac
+ fluid does not get back to heart so heart works harder to compensate and goes into failure
4 = demise
+ leads to demise
what is the assessment of immune hydrops
- assess maternal antibody titers by a blood test
- detailed fetal sonographic assessment for signs of hydrops
- MCA doppler - WITH SEVERE ANEMIA VELOCITY INCREASES due to decreased viscosity of blood
- OOD amnio is performed to assess bilirubin level in amniotic fluid
treatment of immune hydrops
- fetal blood sampling and blood transfusion in utero (PUBS = percutaneous umbilical blood sampling)
- with transfusion many hydropic fetuses survive and many non hydropic fetuses will survive
when is non immune hydrops commonly seen
- 1st and 2nd trimester spontaneously aborted fetuses
what is the etiology of non immune hydrops
- varies geographically
\+ North America and europe
\+ cardiovascular, infection and chromosomal
\+ Southeast Asia
\+ homozygous thalassemiawhat is homozygous thalassaemia
- if others parents pass the gene on to the fetus then the fetus has profound anemia resulting in death in utero
what is heterozygous thalassemia
- if only on parent passes the gene to the fetus then the fetus would have relatively mild red cell anomalies
what are three maternal causes of non immune hydrops
- severe diabetes mellitus
- sever anemia
- TORCH
what are 3 placental causes of non immune hydrops
- chorioangioma (benign mass in placenta blocking flow to baby)
- venous thrombosis
- cord torsion
what are 8 fetal causes of NIH
- cardiac (malform, arrhtym, high output failure)
- thorax and neck (any anomaly of the chest that causes compression)
- urinary (prune belly)
- chromosomal
- infection (CMV, parvovirus, toxoplasmosis)
- skeletal dysplasia
- fetal hypokinesis
- idiopathic
what is the investigation of non immune hydrops
- history (provide clues to etiology)
- detailed scan for markers and anomalies
- fetal echo
- karyotypes
+ FISH = fluorescent in situ hybridization (technique to count chromosomes) - fetal blood sampling
- fetal blood transfusion
- cavity aspiration
- pathology (placneta)
- autopsy (if demise occured)
steps of following NIH
- asses change in degree of hydrops
- cardiothoracic ratios for cardiomegaly
- doppler for cardiac failure
- doppler to asses arterial pulsations in detuses with tricuspid regurge
- perform color over TV for regurge
what does the therapy for NIH depend on
- etiology
treatment for NIH arrhthmyias
- digoxin can be administer to mom
treatment for NIH aneuploidy
- no therapy
treatment for NIH anemia
- transfusion
treatment for NIH chylothorax and CCAM 1
- pleural drainage in utero
- prevent pulmonary hypoplasia
treatment for NIH infections
- maternal or fetal antibiotic
- some fetus have long term adverse effects if not caught soon enough
prognosis of NIH
- mortality still high
- counselling is challenge because no specifics
- termination offered
what are two antenatal therapies
- thoracentisis = removing fluid form fetal chest to help breathing
- paracentesis = removing fluid from fetal abdomen prevent dystocia
three therapies with TTTS
- serial therapeutic amniocentesis for recipient twin
- fetoscopic laser ablation of communicating vessels in placenta
- cord occlusion with TRAP syndrome to prevent cardiac failure od donor twin
