ICD-10-CM > O00-O9A > O30-O48 > O31 > O31.8 > O31.8X > O31.8X9 O31.8X9 Other complications specific to multiple gestation, unspecified trimester Non-Billable/Non-Specific Codes O31.8X90..., not applicable or unspecifiedO31.8X91..., fetus 1O31.8X92..., fetus 2O31.8X93..., fetus 3O31.8X94..., fetus 4O31.8X95..., fetus 5O31.8X99..., other fetus