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ICD-10 Code O99.412: Diseases of the circulatory system complicating pregnancy, second trimester

O99.412 is a billable ICD-10 diagnosis code used to classify Diseases of the circulatory system complicating pregnancy, second trimester in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Pregnancy, childbirth and the puerperium (O00-O9A).

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Pregnancy, childbirth and the puerperium (O00-O9A).

đź“‹Clinical overview

This ICD-10 code is commonly used when documentation describes a maternal circulatory-system disease complicating pregnancy. The most accurate code depends on trimester detail and whether the chart more specifically identifies the underlying cardiac or vascular diagnosis elsewhere in the record.

When is it used?

  • May be used when a clinician documents diseases of the circulatory system complicating pregnancy, second trimester in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

đź©şClinical context

When commonly used
  • Obstetric, cardiology, maternal-fetal medicine, inpatient, and prenatal documentation where maternal circulatory disease materially affects pregnancy monitoring or management.
  • Coding and utilization-review workflows where the record clearly ties maternal circulatory-system disease to pregnancy and trimester timing changes the final complication code.
Common workup
  • Related procedures or service context already linked on this page include Obstetric ultrasound, Fetal nonstress testing.
Common management context
  • Maternal circulatory-system disease follow-up often includes blood-pressure or cardiovascular assessment context, medication review, obstetric monitoring, and coordination with cardiology or maternal-fetal medicine.
  • Documentation usually becomes more specific when the chart identifies trimester timing, the underlying cardiac or vascular diagnosis, severity, and whether additional maternal-fetal surveillance is needed.
  • Specialist context already linked on this page includes Obstetrician, Gynecologist.

🔍Key distinctions

Important notes
  • This ICD-10 family captures maternal circulatory-system disease as a pregnancy-related complication, while separate diagnosis coding may still carry the underlying cardiovascular disorder detail documented elsewhere in the chart.
  • Trimester detail matters, and clearer chart language about the underlying cardiac or vascular condition can add specificity beyond this broad maternal complication family.
  • This title reflects maternal circulatory-system disease complicating pregnancy, which is coded separately from similar maternal circulatory complications during childbirth or the puerperium.
  • Trimester detail is part of the maternal circulatory-system disease code choice, so documentation that clearly states first, second, third, or unspecified trimester affects specificity.
Related codes to consider
O99.411Diseases of the circulatory system complicating pregnancy, first trimester
Related maternal circulatory-system disease ICD-10 code; documentation often becomes more specific when the chart identifies trimester, the underlying cardiovascular diagnosis, or clearer pregnancy context.
O99.413Diseases of the circulatory system complicating pregnancy, third trimester
Related maternal circulatory-system disease ICD-10 code; documentation often becomes more specific when the chart identifies trimester, the underlying cardiovascular diagnosis, or clearer pregnancy context.
O99.419Diseases of the circulatory system complicating pregnancy, unspecified trimester
Related maternal circulatory-system disease ICD-10 code; documentation often becomes more specific when the chart identifies trimester, the underlying cardiovascular diagnosis, or clearer pregnancy context.

Code hierarchy

chapter
15Pregnancy, childbirth and the puerperium (O00-O9A)
block
O94-O9AOther obstetric conditions, not elsewhere classified
category
O99Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
category
O99.4Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium
category
O99.41Diseases of the circulatory system complicating pregnancy
currentO99.41

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

ObstetricianGynecologist

Related procedures

Obstetric ultrasound
May appear in pregnancy follow-up pathways when maternal diseases complicate pregnancy and fetal well-being is monitored.
Fetal nonstress testing
May be used in selected higher-risk pregnancy monitoring pathways.

Coding guidelines

Common synonyms

Diseases of the circulatory system complicating pregnancy, second trimester

Frequently asked questions

Code details

CodeO99.412
SystemICD10
Display nameDiseases of the circulatory system complicating pregnancy, second trimester
ChapterPregnancy, childbirth and the puerperium (O00-O9A)
BlockOther obstetric conditions, not elsewhere classified

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.