ICD-10-CM > O00-O9A > O30-O48 > O40 > O40.1 O40.1 Polyhydramnios, first trimester Non-Billable/Non-Specific Codes O40.1XX0..., not applicable or unspecifiedO40.1XX1..., fetus 1O40.1XX2..., fetus 2O40.1XX3..., fetus 3O40.1XX4..., fetus 4O40.1XX5..., fetus 5O40.1XX9..., other fetus