Hydrops fetalis is a rare disorder associated with significant perinatal complications and a high perinatal mortality of at least 50%. Nonimmune hydrops fetalis (NIHF) is more frequent and results from a wide variety of etiologies. One cause of NIHF is lymphatic malformation 6 (LMPHM6 or generalized lymphatic dysplasia of Fotiou) due to biallelic loss-of-function (LoF) variants in PIEZO1. Most individuals are diagnosed postnatally and only few clinical data are available on fetal presentations. We report six novel biallelic predicted LoF variants in PIEZO1 identified by exome sequencing in six fetuses and one deceased neonate from four unrelated families affected with LMPHM6: three nonsense variants (NM_001142864.4: c.2604T > A, p.(Cys868*); c.7117C > T, p.(Gln2373*) and c.1965C > G, p.(Tyr655*)), two splice-site variants (c.4775 + 1G > A, c.365-1G > A) and one frameshift (c.6468_6469del, p.(Lys2157Glufs*63)). During the pregnancy, most cases are revealed by isolated NIHF at second trimester of gestation. At post-mortem examination ascites, pleural effusions and telengectasies can guide the etiological diagnosis. We aim to further describe the perinatal presentation of this condition which could be underdiagnosed.