O66.3
Obstructed labor due to other abnormalities of fetus
O66.3 (also written O663) is a billable ICD-10-CM diagnosis code for obstructed labor due to other abnormalities of fetus. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 10 codes in category O66 (Other obstructed labor). The Alphabetic Index lists it under 14 entries. Its coding notes include a Use additional code instruction, 1 Excludes1 entry and 4 Excludes2 entries.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
The trimester character comes from the provider's documentation for the current encounter. The unspecified trimester code should rarely be used.
Use additional code
Add the listed code as a secondary code, if known.
- code to identify cause of obstruction
Also from chapter/block level (1 note)
- code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Also from chapter/block level (1 note)
- supervision of normal pregnancy (Z34.-)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (4 notes)
Inclusion terms
Conditions classified to this code.
- Dystocia due to fetal ascites
- Dystocia due to fetal hydrops
- Dystocia due to fetal meningomyelocele
- Dystocia due to fetal sacral teratoma
- Dystocia due to fetal tumor
- Dystocia due to hydrocephalic fetus
Notes
Also from chapter/block level (6 notes)
- CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
- Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
- Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
- 1st trimester- less than 14 weeks 0 days
- 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
- 3rd trimester- 28 weeks 0 days until delivery
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 14 entries
- Deformity, fetal, causing obstructed labor
- Delivery (childbirth) (labor), complicated, by, fetal, deformity
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, conjoined twins
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, fetal, abnormality NEC
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, fetal, ascites
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, fetal, hydrops
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, fetal, meningomyelocele
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, fetal, sacral teratoma
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, fetal, tumor
- Delivery (childbirth) (labor), complicated, by, obstructed labor, due to, dystocia (fetal), due to, hydrocephalic fetus
- Dystocia, fetal, abnormality NEC
- Dystocia, fetal, conjoined twins