ICD-10-CM > O00-O9A > O30-O48 > O41 > O41.0 > O41.00 O41.00 Oligohydramnios, unspecified trimester Non-Billable/Non-Specific Codes O41.00X0..., not applicable or unspecifiedO41.00X1..., fetus 1O41.00X2..., fetus 2O41.00X3..., fetus 3O41.00X4..., fetus 4O41.00X5..., fetus 5O41.00X9..., other fetus