ICD-10-CM > O00-O9A > O30-O48 > O43 > O43.0 > O43.02 O43.02 Fetus-to-fetus placental transfusion syndrome Non-Billable/Non-Specific Codes O43.021Fetus-to-fetus placental transfusion syndrome, first trimesterO43.022Fetus-to-fetus placental transfusion syndrome, second trimesterO43.023Fetus-to-fetus placental transfusion syndrome, third trimesterO43.029Fetus-to-fetus placental transfusion syndrome, unspecified trimester