ICD10
ICD-10 Code O99.1: Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperium
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Pregnancy, childbirth and the puerperium (O00-O9A).
đź“‹Clinical overview
This ICD-10 overview page groups maternal blood, blood-forming-organ, and immune-mechanism complication codes under a broad parent code. The most accurate billable code usually depends on whether the record specifies pregnancy versus childbirth versus puerperium timing and whether the underlying hematologic or immune disorder is named more specifically.
When is it used?
- May be used when a clinician documents other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperium in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
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.
- This entry may represent a broader category rather than the most specific billable code.
đź©şClinical context
When commonly used
- Parent-code browsing, coding review, and clinical-reference workflows where the goal is to understand the broader maternal blood-and-immune complication family before selecting a timing-specific child code.
- Documentation review where the chart clearly links hematologic or immune disease to maternal care, but the user is navigating the broad umbrella page rather than a more specific pregnancy, childbirth, or puerperium child page.
Common workup
- Related procedures or service context already linked on this page include Obstetric ultrasound, Fetal nonstress testing.
Common management context
- Overview-level review often includes CBC or hematology context, medication and transfusion history review when relevant, obstetric monitoring, and coordination with hematology or maternal-fetal medicine.
- The final billable code usually becomes more specific when the chart identifies maternal timing and the exact hematologic or immune disorder family documented elsewhere in the record.
- Specialist context already linked on this page includes Obstetrician, Gynecologist, Hematologist.
🔍Key distinctions
Important notes
- This parent page is an umbrella overview for multiple maternal blood-and-immune complication codes rather than the most specific billable child code.
- Maternal timing and the underlying hematologic or immune diagnosis are the key distinctions across this family.
- This overview page groups maternal blood-and-immune-disorder codes across pregnancy, childbirth, and the puerperium, so the final billable code usually depends on maternal timing and whether the chart identifies a more specific hematologic or immune subtype.
Important exclusions
- hemorrhage with coagulation defects (O45.-, O46.0-, O67.0, O72.3)
Related codes to consider
O99.12Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating childbirth
Related maternal blood-and-immune disorder ICD-10 code; documentation often becomes more specific when the chart identifies maternal timing or the underlying hematologic or immune subtype.
O99.13Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating the puerperium
Related maternal blood-and-immune disorder ICD-10 code; documentation often becomes more specific when the chart identifies maternal timing or the underlying hematologic or immune subtype.
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
currentO99
Official coding notes
Inclusion terms
- Conditions in D65-D89
Excludes1 (do not code together)
- hemorrhage with coagulation defects (O45.-, O46.0-, O67.0, O72.3)
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
ObstetricianGynecologistHematologist
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.
Related codes
Sibling codes
O99.0Anemia complicating pregnancy, childbirth and the puerperiumO99.2Endocrine, nutritional and metabolic diseases complicating pregnancy, childbirth and the puerperiumO99.3Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperiumO99.4Diseases of the circulatory system complicating pregnancy, childbirth and the puerperiumO99.5Diseases of the respiratory system complicating pregnancy, childbirth and the puerperiumO99.6Diseases of the digestive system complicating pregnancy, childbirth and the puerperiumO99.7Diseases of the skin and subcutaneous tissue complicating pregnancy, childbirth and the puerperiumO99.8Other specified diseases and conditions complicating pregnancy, childbirth and the puerperium
Mapped diagnoses and classifications
SNOMED_CT 371106008high
Autoimmune thrombocytopenia in pregnancy
Source: SNOMED International ICD-10 map
SNOMED_CT 128090002high
Benign gestational thrombocytopenia
Source: SNOMED International ICD-10 map
SNOMED_CT 10749581000119100high
Blood coagulation disorder complicating childbirth
Source: SNOMED International ICD-10 map
SNOMED_CT 10749641000119106high
Blood coagulation disorder complicating pregnancy
Source: SNOMED International ICD-10 map
SNOMED_CT 307517001high
Pregnancy-related factor VIII deficiency
Source: SNOMED International ICD-10 map
SNOMED_CT 441697004high
Thrombophilia associated with pregnancy
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
O99.1
Replacement codes
O99.12 — Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating childbirthO99.13 — Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating the puerperium
Common synonyms
Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperium
Frequently asked questions
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.