O88.21 Thromboembolism in pregnancy

ICD-10-CM Code O88.21: Thromboembolism in pregnancy

ICD-10-CM code O88.21 designates the diagnosis of thromboembolism in pregnancy. It is an active concept within the system, classified under the parent code O88.2 for obstetric thromboembolism. The terminology does not list narrower concepts, though related codes distinguish events occurring during childbirth or the puerperium. 1 3

Plain-language overview

The ICD-10-CM code O88.21 identifies a pathologic function specifically described as thromboembolism occurring during pregnancy, providing a standardized diagnostic label for this health condition. 1

What this code represents

Code O88.21 represents an active diagnosis of thromboembolism in pregnancy that is hierarchically grouped under the parent concept O88.2, which is designated for obstetric thromboembolism. 1

The terminology record for O88.21 establishes that this specific code has no narrower child concepts within the ICD-10-CM hierarchy, meaning it does not branch into more specific subcodes. 1

Coding details

While O88.21 denotes thromboembolism in pregnancy generally, related codes include O88.22 for thromboembolism in childbirth and O88.23 for thromboembolism in the puerperium. 3

The code O88.21 is associated with obstetric pulmonary embolism not otherwise specified, and more specific codes exist for events occurring in specific trimesters, such as O88.211 for the first trimester. 4

Documentation considerations

Clinical literature notes that venous thromboembolism during pregnancy and the postpartum period involves various risk factors, and clinical studies address aspects like diagnosis, thrombophilia, treatment, and outcomes. 2

What the sources add

The National Cancer Institute terminology record provides the official structural metadata for O88.21, including its active status and semantic type, whereas the Smart ICD-10 source adds associated synonyms like obstetric embolism NOS. 1 4

Clinical literature from the Bookshelf source provides context on venous thromboembolism risk tools and factors during pregnancy, while the official terminology sources define the exact code boundaries and relationships. 2 1

Coverage and utilization context

The presence of code O88.21 in terminology records and clinical literature establishes its existence for diagnostic classification, but the supplied sources do not contain payer-specific coverage rules or reimbursement guidelines. 1 2

Sources

1. ICD-10-CM O88.21 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
4. Smart ICD 10 — smarticd10.health.belgium.be; accessed 2026-07-27.