| OCA | oculocutaneous albinism; olivopontocerebellar atrophy; oral contraceptive agent |
|---|---|
| OCH | oral contraceptive hormone |
| OCM | oral contraceptive medication |
| OCP | octacalcium phosphate; ocular cicatricial pemphigoid; oral case presentation; oral contraceptive pil... |
| OCS | occipital condyle syndrome; Ondine's curse syndrome; open canalicular system; oral contraceptive ste... |