Non-immune fetal hydrops in late pregnancу: antenatal ultrasound monitoring and pregnancy outcomes in a series of 14 cases
Authors: Safonova I.М. , Sharmazanova O.Р. , Bortniy M.O. , Shapovalova V.V. 
Published: November 2021

Background. Fetal hydrops is the accumulation of extracellular fluid in two or more fetal cavities, often in combination with subcutaneous edema. An isolated accumulation of fluid only in the abdominal, pleural, or pericardial cavities is described as ascites, pleural effusion (hydrothorax), pericardial effusion (hydropericardium). Features of the pathogenesis of non-immune hydrops fetalis (NIHF) are the follow: high hydrophilicity of fetal tissues, obstruction of the lymphatic vessels, impaired lymph return, congestive heart failure, obstruction of venous return, changes in fetal venous pressure. All these factors lead to the release of fluid from cells and tissues into the «third» spaces – the abdominal, thoracic, pericardial cavities, as well as the subcutaneous space. The oncotic pressure of fetal plasma proteins is not of great importance in the formation of the fetal circulating blood volume. Currently, all the links in the pathogenesis of hydrops fetalis syndrome with various etiological factors are not fully known. The prevalence of NIHF is unknown because it is difficult to collect relevant data; many cases of the disease are not diagnosed until intrauterine fetal death or may spontaneously resolve during the prenatal period. Currently, up to 90% of all cases of fetal dropsy are attributed to NIHF. Purpose – acquaintance of the medical community with the diagnosis and treatment of non-immune hydrops as well as the analysis of clinical features, ultrasound monitoring and perinatal outcomes of 14 cases of non-immune fetal hydrops onset in a second half of pregnancy. Materials and methods. The material for the study were publications and results of clinical trials found in the databases Scopus, Web of Science Core Collection and PubMed for the period 2009–2020 and the analytic report of the own series of 14 cases of non-immune hydrops fetalis (NIHF) of various origins. During the period of 2005–2020 under the supervision in the Ultrasound Department of Kharkiv regional hospital with regional perinatal center there were 14 pregnant women with NIHF diagnosed in a second half of pregnancy. Clinical features are described, ultrasound images and Doppler monitoring are given, perinatal / postnatal results are studied. Results and discussion. The analysis of clinical features, ultrasound monitoring and pregnancy outcomes of 14 cases of non-immune fetal hydrops developed in the second half of pregnancy in presented series was carried out. 6/14 fetuses had structural anatomical defects (lung sequestration, СDH, myasthenia gravis, megacystis and hydronephrosis, epidermolysis bullosa, meconium peritonitis, intestinal atresia). Mortality rate (including perinatal and infant losses) was as high as 9/14 cases (64.2%): 3 of antenatal, 4 of neonatal, 2 of infant death). Surgical treatment was performed on 2 newborns. 5 newborns had apparently a favorable clinical postnatal outcome. In 2 cases, spontaneous resolution with complete regression of hydrops was observed (parvovirus-B19 and idiopathic NIHF). Complete recovery of fetus (spontaneous regression of hydrops without any deterioration and pathological consequences) was observed in 1 case. Conclusions. Antenatal ultrasound monitoring of fetus with NIHF is based on the assessment of PSV CMA, ductus venous, umbilical vein, atrioventricular flow. According to the results of the study, it was revealed that the cardiovascular profile of the fetus with NIHF is disturbed earlier, and the placental profile and arterial Doppler-later. Normal umbilical artery Doppler do not exclude the possibility of an adverse outcome, including intrauterine fetal demise. Extended Doppler monitoring is essential at NIHF. All neonates with NIHF in an antenatal anamnesis require postnatal follow-up.