Nonimmune hydrops fetalis may be associated with an elevated delta OD450 in the amniotic fluid.

Nonimmune hydrops fetalis may be associated with an elevated amniotic fluid delta OD450. Cases of I-cell disease (mucolipidosis II), lethal multiple pterygium syndrome, and alpha-thalassemia are presented, each associated with nonimmune hydrops fetalis and an elevated delta OD450. An elevated delta OD450 does not always indicate isoimmunization, and may be due to increased red blood cell turnover for a variety of reasons associated with nonimmune hydrops fetalis.