O36.831 Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester

ICD-10-CM O36.831: Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester

ICD-10-CM code O36.831 identifies maternal care for abnormalities of the fetal heart rate or rhythm during the first trimester of pregnancy. The terminology record is active and classifies the concept as a pathologic function. Fetal heart rate monitoring evaluates fetal wellbeing by assessing baseline heart rate, rhythm, and accelerations or decelerations. 1 2

Plain-language overview

Code O36.831 describes maternal care for abnormalities of the fetal heart rate or rhythm during the first trimester of pregnancy, serving as an active terminology record within the ICD-10-CM version 2026 system. 1

What this code represents

The concept O36.831 is assigned the semantic type of Pathologic Function and has no narrower concepts within the ICD-10-CM terminology record, according to its version 2026 active status. 1

The parent concept for O36.831 is O36.83, which is identified in the terminology record as Maternal care for abnormalities of the fetal heart rate or rhythm. 1

Coding details

A related code, O36.8319, specifies maternal care for abnormalities of the fetal heart rate or rhythm in the first trimester for other fetus, distinguishing it from the target code O36.831. 4 5

Clinical context

Fetal heart rate monitoring is a routine obstetrical procedure worldwide that assesses fetal wellbeing by evaluating the baseline heart rate, rhythm, and the presence or absence of accelerations and decelerations. 2

Intrapartum fetal heart rate monitoring aims to identify inadequately oxygenated fetuses to facilitate timely intervention to prevent fetal damage during the intrapartum period. 2

Documentation considerations

The official published abbreviation for O36.831 is Matern care for abnlt of fetal heart rate or rhym, first tri, which is explicitly documented within the active ICD-10-CM terminology record. 1

What the sources add

While the National Cancer Institute terminology record defines the code hierarchy and semantic type, the biomedical literature source provides clinical context on how fetal heart rate monitoring is used to assess fetal wellbeing. 1 2

The EVS Explore portal confirms the preferred name and semantic type for O36.831, while a separate clinical reference source shows O36.8319 as a related but distinct code for other fetus. 3 5

Sources

1. ICD-10-CM O36.831 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Reliability and agreement in intrapartum fetal heart rate monitoring interpretation: A systematic review — pmc.ncbi.nlm.nih.gov; accessed 2026-07-27.
3. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
4. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
5. O36.8319 - Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester [other fetus] | ICD-10-CM — unboundmedicine.com; accessed 2026-07-27.