This is a pretty gnarly ternary expression that IMO is easier to read as

```ruby
  dei = data_export_identifier

  if dei.starts_with?(PREGNANCY_VISIT_2_2_INTERVIEW_PREFIX) || dei.starts_with?(PREGNANCY_VISIT_2_3_INTERVIEW_PREFIX)
    :due_date_3
  else
    :due_date_2
  end
```

Reason: the value of the expression in the above formulation is not pushed over a hundred-fifty-or-so columns to the side.  This means that you can see what the value of the method is even if the test in the conditional is still quite long.