646.10 — Edema or excessive weight gain in pregnancy, without mention of hypertension, unspecified as to episode of care or not applicable

646.10 is an ICD-9-CM diagnosis code for edema or excessive weight gain in pregnancy, without mention of hypertension, unspecified as to episode of care or not applicable. ICD-9-CM was retired for U.S. claims on October 1, 2015, when ICD-10-CM took over.

The CMS General Equivalence Mappings translate it to 3 ICD-10-CM codes, such as O12.00 (Gestational edema, unspecified trimester), O12.20 (Gestational edema with proteinuria, unspecified trimester) and O26.00 (Excessive weight gain in pregnancy, unspecified trimester). All of these are approximate matches, so review the record to pick the right one.