O41.109
Infection of amniotic sac and membranes, unspecified, unspecified trimester
Not billable — category only FY2026 2025-10-01 → 2026-09-30
This is the unspecified option. 3 more
specific codes sit alongside it. Worth
checking whether the documentation supports one of them.
Exclusions 6 never code together
O00-O9Achapter
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
7th character 7
0 not applicable or unspecified
1 fetus 1
2 fetus 2
3 fetus 3
4 fetus 4
5 fetus 5
9 other fetus this code
Instructional notes 7
O00-O9Achapter
Notes
- CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
- Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
- Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
- 1st trimester- less than 14 weeks 0 days
- 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
- 3rd trimester- 28 weeks 0 days until delivery
Use additional code
- code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.Z3A
Index entries leading here 2
Alongside this code 3 same parent — O41.10
Subordinate codes 7
O41.1090 Infct of amniotic sac and membrns, unsp, unsp tri, unsp O41.1091 Infct of amniotic sac and membrns, unsp, unsp tri, fetus 1 O41.1092 Infct of amniotic sac and membrns, unsp, unsp tri, fetus 2 O41.1093 Infct of amniotic sac and membrns, unsp, unsp tri, fetus 3 O41.1094 Infct of amniotic sac and membrns, unsp, unsp tri, fetus 4 O41.1095 Infct of amniotic sac and membrns, unsp, unsp tri, fetus 5 O41.1099 Infct of amniotic sac and membrns, unsp, unsp trimester, oth
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.