Fetal hydrops can stem from immune or nonimmune causes. Immune causes often involve red cell alloimmunization, whereas nonimmune causes encompass structural malformations, aneuploidy, infections, lymphatic system disorders, genetic syndromes, and more. In a rare and complex case, we encountered a fetal hydrops presentation characterized by blended phenotypes, indicating both a genetic and an underlying immune etiology. The mother, Rhesus negative, presented with a history of adverse obstetric events. At 21 weeks, the current fetus was diagnosed with hydrops. Maternal blood tests unveiled Rhesus alloimmunization, featuring a positive indirect Coombs test at a 1:512 dilution and the presence of anti-D, anti-C, and anti-E antibodies. Fetal blood sampling revealed an O-positive blood group with a hemoglobin level of 10 gm/dL. Despite administering intrauterine transfusion to the fetus, there was no improvement; instead, the fetal hydrops worsened, accompanied by the emergence of nuchal and axillary masses. Exome sequencing of fetal DNA revealed the fetus was homozygous for a pathogenic variant in the SERPINA11 gene and compound heterozygous for a pathogenic variant in the PIEZO1 gene. Furthermore, the combination of pathogenic variants in SERPINA11 and PIEZO1 genes has not been described in cases of fetal hydrops before. This case posed significant challenges in management due to the concurrent presence of both immune and nonimmune hydrops. We describe some of the diagnostic challenges faced in clinical management of this case.

Fetal hydrops can stem from immune or nonimmune causes. Immune causes often involve red cell alloimmunization, whereas nonimmune causes encompass structural malformations, aneuploidy, infections, lymphatic system disorders, genetic syndromes, and more. In a rare and complex case, we encountered a fetal hydrops presentation characterized by blended phenotypes, indicating both a genetic and an underlying immune etiology. The mother, Rhesus negative, presented with a history of adverse obstetric events. At 21 weeks, the current fetus was diagnosed with hydrops. Maternal blood tests unveiled Rhesus alloimmunization, featuring a positive indirect Coombs test at a 1:512 dilution and the presence of anti-D, anti-C, and anti-E antibodies. Fetal blood sampling revealed an O-positive blood group with a hemoglobin level of 10 gm/dL. Despite administering intrauterine transfusion to the fetus, there was no improvement; instead, the fetal hydrops worsened, accompanied by the emergence of nuchal and axillary masses. Exome sequencing of fetal DNA revealed the fetus was homozygous for a pathogenic variant in the SERPINA11 gene and compound heterozygous for a pathogenic variant in the PIEZO1 gene. Furthermore, the combination of pathogenic variants in SERPINA11 and PIEZO1 genes has not been described in cases of fetal hydrops before. This case posed significant challenges in management due to the concurrent presence of both immune and nonimmune hydrops. We describe some of the diagnostic challenges faced in clinical management of this case.

Bartter syndrome is a group of autosomal recessive renal tubular disorders; it has two types of presentation: antenatal and classic. The antenatal type presents as severe unexplained polyhydramnios in the second trimester. This is due to fetal urinary losses of sodium, chloride, and potassium, leading to fetal polyuria. The classic type presents in the late neonatal or infancy stage, with dehydration, dyselectrolytemia, failure to thrive, and nephrocalcinosis. Antenatal scans are normal in such cases. Type I and II Bartter syndrome presents in the antenatal period, whereas type IV has a classic presentation. We describe an unusual case of type IVa Bartter syndrome presenting in the antenatal period, with severe polyhydramnios. The initial diagnosis was made based on amniotic fluid chloride levels and later confirmed by performing a genetic test. Genetic testing is important for confirming diagnosis and prognostication regarding the condition.

Bartter syndrome is a group of autosomal recessive renal tubular disorders; it has two types of presentation: antenatal and classic. The antenatal type presents as severe unexplained polyhydramnios in the second trimester. This is due to fetal urinary losses of sodium, chloride, and potassium, leading to fetal polyuria. The classic type presents in the late neonatal or infancy stage, with dehydration, dyselectrolytemia, failure to thrive, and nephrocalcinosis. Antenatal scans are normal in such cases. Type I and II Bartter syndrome presents in the antenatal period, whereas type IV has a classic presentation. We describe an unusual case of type IVa Bartter syndrome presenting in the antenatal period, with severe polyhydramnios. The initial diagnosis was made based on amniotic fluid chloride levels and later confirmed by performing a genetic test. Genetic testing is important for confirming diagnosis and prognostication regarding the condition.