Diagnosis
It is commonly expected to simultaneously identify maternal and fetal
findings to diagnose Mirror syndrome. However, described cases in the
literature show that this is not always the case and fetal findings may
predate maternal presentation and vice-versa. This pattern needs to be
kept in mind to allow for diagnostic accuracy and inclusion of Mirror
syndrome in differentials.
Maternal presentation in Mirror syndrome is significantly similar to
that of PE; both include elevated arterial pressure, edema, weight gain
and proteinuria, which makes differentiating between the two one of the
biggest diagnostic challenges in patients with this symptomatology. The
unique features of Mirror syndrome include younger gestational age at
diagnosis (Mirror syndrome has an earlier onset with more than 50% of
cases diagnosed between 26.5 and 27.5 weeks4) and
maternal presence of hemodilution (decrease in hematocrit and
hemoglobin).
Fetal presentation of hydrops fetalis is also a differentiating factor;
it is characterized by excessive fluid accumulation within the fetal
extravascular components and body cavities. It can have different
etiologies and determining the exact cause is important for management
of Mirror syndrome.