O66.3 Obstructed labor due to other abnormalities of fetus

Billable ICD-10-CM code, FY2026.

Applicable to

• 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

Use additional code

• code to identify cause of obstruction

MS-DRG index

Defines the logic of DRG(s) 817-819 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 660.81 Other causes of obstructed labor, delivered, with or without mention of antepartum condition (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O66.3

Back-references to O66.3

• Type 1 Excludes: O33.7 Maternal care for disproportion due to other fetal deformities ("obstructed labor due to other fetal deformities (O66.3)")
• Type 1 Excludes: O65.4 Obstructed labor due to fetopelvic disproportion, unspecified ("dystocia due to abnormality of fetus (O66.2-O66.3)")

Back-references to O66

• Type 1 Excludes: O33 Maternal care for disproportion ("disproportion with obstructed labor (O65-O66)")

Diagnosis Index entries for O66.3

• 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
• Hydrocephalus (acquired) (external) (internal) (malignant) (recurrent) › causing disproportion › with obstructed labor
• Hydrops › causing obstructed labor (mother)

Nearby codes

• O66 Other obstructed labor
• O66.0 Obstructed labor due to shoulder dystocia
• O66.1 Obstructed labor due to locked twins
• O66.2 Obstructed labor due to unusually large fetus
• O66.3 Obstructed labor due to other abnormalities of fetus (this code)
• O66.4 Failed trial of labor
• O66.40 Failed trial of labor, unspecified
• O66.41 Failed attempted vaginal birth after previous cesarean delivery
• O66.5 Attempted application of vacuum extractor and forceps
• O66.6 Obstructed labor due to other multiple fetuses