The START bit of the first character begins with a transition from High to Low (with TRUE levels).

If the pin is not in the High state, the start bit will be missed and the first data sent will be out of sync.
It will be able to sync up after any pause in the data stream greater than 1-byte in length.

To initialize the pin, you should set it to output, in the "Idle State" for at least 1 byte length (8.3 mS for 1200 baud).
So just set the pin high, pause 10 mS and you should be fine.