ICD-10-CM > O00-O9A > O30-O48 > O31 > O31.1 > O31.13 O31.13 Continuing pregnancy after spontaneous abortion of one fetus or more, third trimester Non-Billable/Non-Specific Codes O31.13X0..., not applicable or unspecifiedO31.13X1..., fetus 1O31.13X2..., fetus 2O31.13X3..., fetus 3O31.13X4..., fetus 4O31.13X5..., fetus 5O31.13X9..., other fetus