Maternity notes?

Sasha • First pregnancy! Due on the 4th of December with a baby girl👼🏻
What does ROP and RO2 mean? On my maternity notes it says ROP under the POSN column, and I can't seem to fine what it means. Then my last two appointments it has been RO2 so I'm just wondering what it means!! Thank you if anyone can help☺️