Non-immune hydrops fetalis: Two case reports

BACKGROUND: Fetal hydrops is a serious condition difficult to manage, often with a poor prognosis, and it is characterized by the collection of fluid in the extravascular compartments. Before 1968, the most frequent cause was the maternal-fetal Rh incompatibility. Today, 90% of the cases are non-immune hydrops fetalis. Multiple fetal anatomic and functional disorders can cause non-immune hydrops fetalis and the pathogenesis is incompletely understood. Etiology varies from viral infections to heart disease, chromosomal abnormalities, hematological and autoimmune causes. CASE SUMMARY: A 38-year-old pregnant woman has neck lymphoadenomegaly, fever, cough, tonsillar plaques at 14 wk of amenorrhea and a rash with widespread itching. At 27.5 wk a fetal ultrasound shows signs of severe anemia and hydrops. Cordocentesis is performed with confirmation of severe fetal anemia and subsequent fetal transfusion. The karyotype is 46, XX, array-comparative genome hybridization (CGH) negative, and infectious tests are not conclusive. In the following days there is a progressive improvement of the indirect signs of fetal anemia. At 33.6 wk, for relapse of severe fetal anemia, further fetal transfusions are necessary and an urgent cesarean section is performed. On the day 12 of life, for the detection of anemia, the newborn is subjected to transfusion of concentrated red blood cells and begins treatment with erythropoietin. Later there is a normalization of blood chemistry values and the baby does not need new transfusions. A 29-year-old pregnant woman, with Sjogren's syndrome and positive Anti-Ro/SSA antibodies, is subjected to serial fetal ecocardio for branch block. At 26.5 wk there is a finding of fetal ascites. Infectious disease tests on amniotic fluid are negative as well as quantitative fluorescent polymerase chain reaction, Array CGH. At cordocentesis Hb is 1.3 mmol/L, consequently fetal transfusion is performed. Also in this case, due to continuous episodes of relapse of fetal anemia with consequent transfusions, at 29.4 wk a cesarean section is performed. On day 9 of life, a treatment with erythropoietin is started in the newborn, but the baby needs three blood transfusions. The search for autoantibodies in the baby found SS-A Ro60 positive, SSA-Ro52 positive and SS-B negative. The hemoglobin values normalized after the disappearance of maternal autoantibodies. CONCLUSION: An attempt to determine the etiology of hydrops should be made at the time of diagnosis because the goal is to treat underlying cause, whenever possible. Even if the infectious examinations are not conclusive, but the pregnancy history is strongly suggestive of infection as in the first case, the infectious etiology must not be excluded. In the second case, instead, transplacental passage of maternal autoantibodies caused hydrops fetalis and severe anemia. Finally, obstetric management must be aimed at fetal support up to an optimal timing for delivery by evaluating risks and benefits to increase the chances of survival without sequelae.