O31.4
Continuing pregnancy after vanishing twin syndrome of one fetus or more
O31.4 is a non-billable ICD-10-CM code header for continuing pregnancy after vanishing twin syndrome of one fetus or more. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are O31.40 Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester; O31.41 Continuing pregnancy after vanishing twin syndrome of one fetus or more, first trimester; O31.42 Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester and O31.43 Continuing pregnancy after vanishing twin syndrome of one fetus or more, third trimester. Its coding notes include a Use additional code instruction, 1 Excludes1 entry and 7 Excludes2 entries.
7th characters
Every code below needs one of these (defined at O31).
One of the following 7th characters is to be assigned to each code under category O31. 7th character 0 is for single gestations and multiple gestations where the fetus is unspecified. 7th characters 1 through 9 are for cases of multiple gestations to identify the fetus for which the code applies. The appropriate code from category O30, Multiple gestation, must also be assigned when assigning a code from category O31 that has a 7th character of 1 through 9.
- 0not applicable or unspecified
- 1fetus 1
- 2fetus 2
- 3fetus 3
- 4fetus 4
- 5fetus 5
- 9other fetus
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.
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)
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. 2 entries
More specific codes under O31.4 4
- O31.40Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester7th char needed
- O31.41Continuing pregnancy after vanishing twin syndrome of one fetus or more, first trimester7th char needed
- O31.42Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester7th char needed
- O31.43Continuing pregnancy after vanishing twin syndrome of one fetus or more, third trimester7th char needed