Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 1
Under O31.40 Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, in Maternal care related to the fetus and amniotic cavity and possible delivery problems (O30-O48), chapter 15: Pregnancy, Childbirth and the Puerperium
- O31.40X1 is an unspecified code: use it only when the record doesn't document anything more specific. If the record has more detail, check the other codes under O31.40 below.
- As a secondary diagnosis it is not a CC or MCC, so it doesn't raise the MS-DRG payment.
- Expected only on maternity records. (Maternity list)
Instructional notes
Also applies, from O31: Complications specific to multiple gestation
These notes sit on O31 and apply to every code under it, including O31.40X1.
Other codes under O31.40
Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester
- O31.40X0Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, not applicable or unspecified
- O31.40X1Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 1(this code)
- O31.40X2Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 2
- O31.40X3Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 3
- O31.40X4Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 4
- O31.40X5Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 5
- O31.40X9Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, other fetus
MS-DRGs
As the principal diagnosis, this code groups to these MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.
- DRG 817 Other Antepartum Diagnoses with O.R. Procedures with MCC
- DRG 818 Other Antepartum Diagnoses with O.R. Procedures with CC
- DRG 819 Other Antepartum Diagnoses with O.R. Procedures without CC/MCC
- DRG 831 Other Antepartum Diagnoses without O.R. Procedures with MCC
- DRG 832 Other Antepartum Diagnoses without O.R. Procedures with CC
- DRG 833 Other Antepartum Diagnoses without O.R. Procedures without CC/MCC
About the condition
Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.
Twins, Triplets, Multiple Births
If you are pregnant with more than one baby, you are far from alone. Multiple births are up in the United States. More women are having babies after age 30 and more are taking fertility drugs. Both boost the chance of carrying more than one baby. A family history of twins also makes multiples more likely.
Read more about twins, triplets, multiple births on MedlinePlusCode history
Added in FY2027 (effective October 1, 2026). Before that, these cases were coded as O31.8X91 (Other complications specific to multiple gestation, unspecified trimester, fetus 1). No changes since.