Coding corner: best practices for documenting pregnancy, childbirth and puerperium

The introduction of ICD-10-CM coding on Oct. 1, 2015, brought many changes to how we code pregnancies and the complications of pregnancies. ICD-10-CM coding captures a greater level of specificity for obstetric conditions, as it does for other conditions. Let’s explore some of these changes.

ICD-10-CM official guidelines for reporting and coding

“Pregnancy, Childbirth, and the Puerperium” is found in Chapter 15 of the ICD-10-CM coding manual. The majority of the codes in this chapter have a final character indicating the pregnancy trimester. Trimesters are counted from the first day of the last menstrual period and are defined as follows:

• First trimester — less than 14 weeks, 0 days
• Second trimester — 14 weeks, 0 days to less than 28 weeks, 0 days
• Third trimester — 28 weeks, 0 days until delivery

For example:

• O09.00 — Supervision of pregnancy with history of infertility, unspecified trimester
• O09.291 — Supervision of pregnancy with other poor reproductive or obstetric history, first trimester

Codes from category Z3A are for use only on the maternal record to indicate the pregnancy gestation weeks. Remember to first code complications of pregnancy, childbirth, puerperium (o00-o9A):

• O09.291 — Supervision of pregnancy with other poor reproductive or obstetric history, first trimester
• Z3A.09 — Nine weeks gestation of pregnancy

This is especially important as some providers are submitting Z3A codes as a reason for performing ultrasounds. These informational codes are not payable because they don’t code to an actual condition. These codes should only be reported as a secondary diagnosis.

If a trimester is not a component of a code, it’s because the condition always occurs in a specific trimester or the pregnancy trimester is not applicable. Certain codes have characters for only certain trimesters because the condition doesn’t occur in all trimesters. For example:

• O21.2 — Late vomiting during pregnancy (excessive vomiting that starts after 20 weeks of gestation)

The provider’s documentation of the number of weeks of pregnancy may be used to assign the appropriate code identifying the trimester.

Note: To avoid claim rejection after a patient receives an ultrasound, consider the following:

Example A: A member who is 16 weeks pregnant with twins (monochorionic monoamniotic) arrives for an ultrasound. Apply the complication code, the appropriate gestation code and the appropriate CPT code:

• O30.012 — Twin pregnancy (monochorionic monoamniotic), second trimester
• Z3A.16 — 16 weeks of gestation of pregnancy
• Appropriate CPT code

Example B: A member who is nine weeks pregnant arrives for a routine fetal ultrasound. Apply normal screening code first (uncomplicated pregnancy), followed by the appropriate CPT code:

• Z36 — Encounter for antenatal screening of mother
• Appropriate CPT code

Maternal record

Chapter 15 codes are to be used only on the maternal record, never on the newborn’s record. Codes from this chapter should be used for conditions related to or aggravated by the pregnancy, childbirth or by the puerperium (maternal causes or obstetric cases). For example:

• O00.1 — Tubal pregnancy

For the category O00, use any additional code from category O08 to identify any associated complications:

• O00.1 — Tubal pregnancy
• O08.1 — Delayed or excessive hemorrhage following ectopic and molar pregnancy

Status codes used only on the maternal record are from category Z37. For example, outcome of delivery category Z37.

Outcome of delivery codes should be included on every maternal record when a delivery has occurred. These codes shouldn’t be used on subsequent records or on the newborn record. Here are a few examples from category Z37:

• Z37.0 — Single live birth
• Z37.50 — Multiple births, unspecified, all live born
• Z37.9 — Outcome of delivery, unspecified

Note:  These codes shouldn’t be reported as a primary diagnosis on professional claims because they are informational in nature and don’t code to a reason for the service. They should only be used on the mother’s claim as a secondary diagnosis.

There are codes exclusively for the newborn record, such as category Z38. For example, Z38 “live born infants according to place of birth and type of delivery.” Here are a few examples from category Z38:

• Z38.0 — Single live born infant, born in hospital
• Z38.63 — Quadruplet live born infant, delivered vaginally
• Z38.8 — Other multiple live born infants, unspecified as to place of birth

HIV infection in pregnancy, childbirth and puerperium

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 disease complicating pregnancy, childbirth and the puerperium,” followed by the code(s) for the HIV-related illness(es). For example:

• A patient presenting for an HIV-related illness should receive a principal diagnosis code O98.7 — followed by category B20 and the code(s) for the HIV illness(es) such as
• Pneumonia
• Herpes zoster
• HIV wasting syndrome, etc.
• Remember, codes from Chapter 15, “Pregnancy, Childbirth and the Puerperium,” always take sequencing priority
• O98.713 — HIV disease complicating pregnancy, third trimester
• B20 — HIV disease
• J15.4 — Pneumonia due to other streptococci
• Z3A.30 — 30 weeks gestation of pregnancy
• Patients with asymptomatic HIV infection status admitted (or presenting for a health care encounter) during pregnancy, childbirth or the puerperium should receive codes O98.7- and Z21.

Diabetes mellitus in pregnancy

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

Codes for gestational diabetes are in subcategory O24.4, gestational diabetes mellitus. Other codes from category O24, diabetes mellitus in pregnancy, childbirth and the puerperium, shouldn’t be assigned. For example:

• O24.011 — Pre-existing diabetes, type 1, in pregnancy, first trimester
• E10.9 — Type 1 diabetes mellitus, without complications
• Z79.4 — Long term use of insulin
• Z3A.09 — Nine weeks gestation of pregnancy

Consider the codes for gestational (pregnancy-induced) diabetes:

• O24.420 — Gestational diabetes mellitus in childbirth, diet controlled
• Z3A.37 — 37 weeks gestation of pregnancy
• Z37.0 — Single live birth
• Remember: Subcategory O24.4 includes diet and insulin-controlled codes. The use of code Z79.4 for long-term use of insulin is not needed

To ensure complete and accurate documentation and correct coding, be sure to code all pregnancy and pregnancy-related complications to the highest level of specificity.

None of the information included in this article is intended to be legal advice and, as such, it remains the provider’s responsibility to ensure that all coding and documentation are done in accordance with applicable state and federal laws and regulations.