The cis-MR analyses revealed the causal protective effect of the BANK1 locus on AF (OR = 0.528, 95% CI = 0.322–0.867; P = 0.012) and HF (OR = 0.441, 95% CI = 0.247–0.785; P = 0.005), as well as the BUD13 locus on HF (OR = 0.541, 95% CI = 0.381–0.768; P = 0.021). This evidence concerns the gene BUD13 and hydrops fetalis.