ICD10BillableValid for clinical use
ICD-10 Code O23.03: Infections of kidney in pregnancy, third trimester
Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026
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 kidney infection during pregnancy. The most accurate code depends on trimester timing and whether the record clearly supports upper urinary-tract or kidney infection rather than a lower urinary infection alone.
When is it used?
- May be used when a clinician documents infections of kidney in pregnancy, third 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, prenatal, emergency, and inpatient documentation where kidney infection or pyelonephritis affects maternal pregnancy management.
- Coding and utilization-review workflows where the record clearly ties renal or upper-tract infection to pregnancy and documents trimester timing.
Common workup
- Common related testing on this page includes Urinalysis, Urine culture, Complete blood count.
- Related procedures or service context already linked on this page include Obstetric ultrasound, Fetal nonstress testing.
Common management context
- Pregnancy kidney-infection follow-up often includes urinalysis, urine culture, broader infection assessment, and coordination of maternal monitoring alongside pregnancy follow-up.
- Documentation usually becomes more specific when the chart identifies trimester, pyelonephritis or kidney involvement, organism detail, or associated maternal monitoring needs.
- Specialist context already linked on this page includes Obstetrician, Gynecologist, Infectious Disease Specialist, Urologist.
🔍Key distinctions
Important notes
- This ICD-10 family captures kidney infection in pregnancy, and the pregnancy timing is part of what makes these codes distinct from non-obstetric urinary or kidney infection diagnoses.
- Trimester detail matters, while clearer chart language about upper-tract versus lower-tract infection can change code specificity inside the pregnancy context.
- This title reflects kidney infection in pregnancy, which is coded separately from lower urinary-tract infection in pregnancy and often carries more systemic infection risk.
- Trimester detail is part of the maternal kidney-infection code choice, so documentation that clearly states first, second, or third trimester affects specificity.
Related codes to consider
O23.00Infections of kidney in pregnancy, unspecified trimester
Related pregnancy kidney-infection ICD-10 code; documentation often becomes more specific when the chart identifies trimester timing, upper-versus-lower urinary involvement, organism detail, or clearer pregnancy context.
O23.01Infections of kidney in pregnancy, first trimester
Related pregnancy kidney-infection ICD-10 code; documentation often becomes more specific when the chart identifies trimester timing, upper-versus-lower urinary involvement, organism detail, or clearer pregnancy context.
O23.02Infections of kidney in pregnancy, second trimester
Related pregnancy kidney-infection ICD-10 code; documentation often becomes more specific when the chart identifies trimester timing, upper-versus-lower urinary involvement, organism detail, or clearer pregnancy context.
Code hierarchy
chapter
15Pregnancy, childbirth and the puerperium (O00-O9A)
block
O20-O29Other maternal disorders predominantly related to pregnancy
category
O23Infections of genitourinary tract in pregnancy
category
O23.0Infections of kidney in pregnancy
currentO23.0
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
ObstetricianGynecologistInfectious Disease SpecialistUrologist
Related tests
Urinalysis
Commonly reviewed when evaluating urinary tract infection in pregnancy.
Urine culture
Often used to help identify urinary pathogens in pregnancy-related infection workup.
Complete blood count
May be reviewed as part of broader infection assessment in pregnancy.
Related procedures
Obstetric ultrasound
May appear in pregnancy follow-up pathways when infection is being assessed alongside fetal well-being.
Fetal nonstress testing
May be used in selected higher-risk pregnancy monitoring pathways.
Related codes
Sibling codes
Coding guidelines
Common synonyms
Infections of kidney in pregnancy, third trimester
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.