O22.21

Chapter 15 codes are to be used only on the maternal record, never on the record of the newborn.

The majority of codes in Chapter 15 have a final character indicating the trimester of pregnancy. The timeframes for the trimesters are indicated at the beginning of the chapter. If trimester is not a component of a code, it is because the condition always occurs in a specific trimester, or the concept of trimester of pregnancy is not applicable. Certain codes have characters for only certain trimesters because the condition does not occur in all trimesters, but it may occur in more than just one. Assignment of the final character for trimester should be based on the provider’s documentation of the trimester (or number of weeks) for the current admission/encounter. This applies to the assignment of trimester for pre-existing conditions as well as those that develop during or are due to the pregnancy. The provider’s documentation of the number of weeks may be used to assign the appropriate code identifying the trimester. Whenever delivery occurs during the current admission, and there is an “in childbirth” option for the obstetric complication being coded, the “in childbirth” code should be assigned. When the classification does not provide an obstetric code with an “in childbirth” option, it is appropriate to assign a code describing the current trimester.

more than one trimester In instances when a patient is admitted to a hospital for complications of pregnancy during one trimester and remains in the hospital into a subsequent trimester, the trimester character for the antepartum complication code should be assigned on the basis of the trimester when the complication developed, not the trimester of the discharge. If the condition developed prior to the current admission/encounter or represents a pre-existing condition, the trimester character for the trimester at the time of the admission/encounter should be assigned.

Each category that includes codes for trimester has a code for “unspecified trimester.” The “unspecified trimester” code should rarely be used, such as when the documentation in the record is insufficient to determine the trimester and it is not possible to obtain clarification.

Where applicable, a 7 character is to be assigned for certain categories (O31, O32, O33.3 - O33.6, O35, O36, O40, O41, O60.1, O60.2, O64, and O69) to identify the fetus for which the complication code applies. Assign 7 character “0”: • For single gestations • When the documentation in the record is insufficient to determine the fetus affected and it is not possible to obtain clarification. • When it is not possible to clinically determine which fetus is affected.

In ICD-10-CM, “completed” weeks of gestation refers to full weeks. For example, if the provider documents gestation at 39 weeks and 6 days, the code for 39 weeks of gestation should be assigned, as the patient has not yet reached 40 completed weeks.

For routine outpatient prenatal visits when no complications are present, a code from category Z34, Encounter for supervision of normal pregnancy, should be used as the first-listed diagnosis. These codes should not be used in conjunction with chapter 15 codes.

Codes from category O09, Supervision of high-risk pregnancy, are intended for use only during the prenatal period. For complications during the labor or delivery episode as a result of a high-risk pregnancy, assign the applicable complication codes from Chapter 15. If there are no complications during the labor or delivery episode, assign code O80, Encounter for full-term uncomplicated delivery. For routine prenatal outpatient visits for patients with high-risk pregnancies, a code from category O09, Supervision of high-risk pregnancy, should be used as the first-listed diagnosis. Secondary chapter 15 codes may be used in conjunction with these codes if appropriate.

In episodes when no delivery occurs, the principal diagnosis should correspond to the principal complication of the pregnancy which necessitated the encounter. Should more than one complication exist, all of which are treated or monitored, any of the complication codes may be sequenced first.

When an obstetric patient is admitted and delivers during that admission, the condition that prompted the admission should be sequenced as the principal diagnosis. If multiple conditions prompted the admission, sequence the one most related to the delivery as the principal diagnosis. A code for any complication of the delivery should be assigned as an additional diagnosis. In cases of cesarean delivery, if the patient was admitted with a condition that resulted in the performance of a cesarean procedure, that condition should be selected as the principal diagnosis. If the reason for the admission was unrelated to the condition resulting in the cesarean delivery, the condition related to the reason for the admission should be selected as the principal diagnosis.

A code from category Z37, Outcome of delivery, should be included on every maternal record when a delivery has occurred. These codes are not to be used on subsequent records or on the newborn record.

Certain categories in Chapter 15 distinguish between conditions of the mother that existed prior to pregnancy (pre-existing) and those that are a direct result of pregnancy. When assigning codes from Chapter 15, it is important to assess if a condition was pre-existing prior to pregnancy or developed during or due to the pregnancy in order to assign the correct code. Categories that do not distinguish between pre-existing and pregnancy-related conditions may be used for either. It is acceptable to use codes specifically for the puerperium with codes complicating pregnancy and childbirth if a condition arises postpartum during the delivery encounter.

Category O10, Pre-existing hypertension complicating pregnancy, childbirth and the puerperium, includes codes for hypertensive heart and hypertensive chronic kidney disease. When assigning one of the O10 codes that includes hypertensive heart disease or hypertensive chronic kidney disease, it is necessary to add a secondary code from the appropriate hypertension category to specify the type of heart failure or chronic kidney disease. See Section I.C.9. Hypertension.

Codes from categories O35, Maternal care for known or suspected fetal abnormality and damage, and O36, Maternal care for other fetal problems, are assigned only when the fetal condition is actually responsible for modifying the management of the mother, i.e., by requiring diagnostic studies, additional observation, special care, or termination of pregnancy. The fact that the fetal condition exists does not justify assigning a code from this series to the mother’s record.

In cases when surgery is performed on the fetus, a diagnosis code from category O35, Maternal care for known or suspected fetal abnormality and damage, should be assigned identifying the fetal condition. Assign the appropriate procedure code for the procedure performed. No code from Chapter 16, the perinatal codes, should be used on the mother’s record to identify fetal conditions. Surgery performed in utero on a fetus is still to be coded as an obstetric encounter.

During pregnancy, childbirth or the puerperium, a patient admitted because of an HIV-related illness should receive a principal diagnosis from subcategory O98.7-, Human immunodeficiency [HIV] disease complicating pregnancy, childbirth and the puerperium, followed by the code(s) for the HIV-related illness(es). Patients with asymptomatic HIV infection status admitted during pregnancy, childbirth, or the puerperium should receive codes of O98.7- and Z21, Asymptomatic human immunodeficiency virus [HIV] infection status.

Diabetes mellitus is a significant complicating factor in pregnancy. Pregnant patients who are diabetic should be assigned a code from category O24, Diabetes mellitus in pregnancy, childbirth, and the puerperium, first, followed by the appropriate diabetes code(s) (E08-E13) from Chapter 4.

See section I.C.4.a.3 for information on the long-term use of insulin and oral hypoglycemics.

Gestational (pregnancy induced) diabetes can occur during the second and third trimester of pregnancy in patients who were not diabetic prior to pregnancy. Gestational diabetes can cause complications in the pregnancy similar to those of pre-existing diabetes mellitus. It also puts the patient at greater risk of developing diabetes after the pregnancy. Codes for gestational diabetes are in subcategory O24.4, Gestational diabetes mellitus. No other code from category O24, Diabetes mellitus in pregnancy, childbirth, and the puerperium, should be used with a code from O24.4. The codes under subcategory O24.4 include diet controlled, insulin controlled, and controlled by oral hypoglycemic drugs. If a patient with gestational diabetes is treated with both diet and insulin, only the code for insulin-controlled is required. If a patient with gestational diabetes is treated with both diet and oral hypoglycemic medications, only the code for "controlled by oral hypoglycemic drugs" is required. Codes Z79.4, Long-term (current) use of insulin, Z79.84, Long-term (current) use of oral hypoglycemic drugs, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs, should not be assigned with codes from subcategory O24.4. An abnormal glucose tolerance in pregnancy is assigned a code from subcategory O99.81, Abnormal glucose complicating pregnancy, childbirth, and the puerperium.

When assigning a chapter 15 code for sepsis complicating abortion, pregnancy, childbirth, and the puerperium, a code for the specific type of infection should be assigned as an additional diagnosis. If severe sepsis is present, a code from subcategory R65.2, Severe sepsis, and code(s) for associated organ dysfunction(s) should also be assigned as additional diagnoses.

Code O85, Puerperal sepsis, should be assigned with a secondary code to identify the causal organism (e.g., for a bacterial infection, assign a code from category B95-B96, Bacterial infections in conditions classified elsewhere). A code from category A40, Streptococcal sepsis, or A41, Other sepsis, should not be used for puerperal sepsis. If applicable, use additional codes to identify severe sepsis (R65.2-) and any associated acute organ dysfunction. Code O85 should not be assigned for sepsis following an obstetrical procedure (See Section I.C.1.d.5.b., Sepsis due to a postprocedural infection).

Codes under subcategory O99.31, Alcohol use complicating pregnancy, childbirth, and the puerperium, should be assigned for any pregnancy case when a patient uses alcohol during the pregnancy or postpartum. A secondary code from category F10, Alcohol related disorders, should also be assigned to identify manifestations of the alcohol use.