ICD10
ICD-10 Code O99.11: Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy
Reviewed by HealthAssure Clinical TeamUpdated 21 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 code is commonly used when documentation describes another blood, blood-forming-organ, or immune-mechanism disorder complicating pregnancy, childbirth, or the puerperium. The most accurate code depends on maternal timing and whether the chart later identifies the underlying hematologic or immune disorder 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 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
- Obstetric, prenatal, inpatient, hematology, and maternal-fetal medicine documentation where a maternal blood or immune disorder materially affects pregnancy monitoring, delivery planning, or postpartum recovery.
- Coding and utilization-review workflows where the record clearly ties hematologic or immune-mechanism disease context to pregnancy, childbirth, or the puerperium and 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 blood-and-immune disorder follow-up often includes CBC or related lab review context, medication and transfusion history review when relevant, obstetric monitoring, and coordination with hematology or subspecialty care.
- Documentation usually becomes more specific when the chart identifies the underlying blood disorder, immune condition, trimester detail, delivery timing, or puerperium context elsewhere in the record.
- Specialist context already linked on this page includes Obstetrician, Gynecologist, Hematologist.
🔍Key distinctions
Important notes
- This ICD-10 family captures maternal blood and immune disorders as pregnancy-related complications, while separate diagnosis coding may still carry the underlying hematologic or immune disease detail documented elsewhere in the chart.
- Pregnancy, childbirth, puerperium, and trimester timing matter, and clearer chart language about the underlying disorder can add specificity beyond this broad maternal complication family.
- This title reflects maternal blood or blood-forming-organ disease complicating pregnancy-related care, which is coded separately from the childbirth or puerperium versions of the same obstetric complication family.
- Maternal immune-mechanism disorder context can change code selection inside this family when the chart makes the hematologic or immune disorder more explicit elsewhere in the record.
Related codes to consider
O99.111Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, first trimester
Related maternal blood-and-immune disorder ICD-10 code; documentation often becomes more specific when the chart identifies trimester, delivery timing, puerperium context, or the underlying hematologic or immune disorder.
O99.112Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, second trimester
Related maternal blood-and-immune disorder ICD-10 code; documentation often becomes more specific when the chart identifies trimester, delivery timing, puerperium context, or the underlying hematologic or immune disorder.
O99.113Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, third trimester
Related maternal blood-and-immune disorder ICD-10 code; documentation often becomes more specific when the chart identifies trimester, delivery timing, puerperium context, or the underlying hematologic or immune disorder.
O99.119Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, unspecified trimester
Related maternal blood-and-immune disorder ICD-10 code; documentation often becomes more specific when the chart identifies trimester, delivery timing, puerperium context, or the underlying hematologic or immune disorder.
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
O99.1Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperium
currentO99.1
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
O99.111Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, first trimestercodeO99.112Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, second trimestercodeO99.113Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, third trimestercodeO99.119Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, unspecified trimestercode
Sibling codes
Coding guidelines
Common synonyms
Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy
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.