July 7 2008
Coding for Prematurity
A normal, full-term pregnancy typically lasts 40 weeks. A premature birth takes place more than three weeks before the 40th week. On the mother’s record, premature birth is classified to ICD-9-CM code 644.21. The coding notes under code 644.2 state, “Onset (spontaneous) of delivery, before 37 completed weeks of gestation” and “Premature labor with onset of delivery, before 37 completed weeks of gestation.” On the newborn’s record, prematurity is classified to code 765.1, and extreme immaturity is assigned to code 765.0.
Both codes require one of the following fifth-digit subclassifications:
0 — unspecified weight;
1 — less than 500 grams;
2 — 500 to 749 grams;
3 — 750 to 999 grams;
4 — 1,000 to 1,249 grams;
5 — 1,250 to 1,499 grams;
6 — 1,500 to 1,749 grams;
7 — 1,750 to 1,999 grams;
8 — 2,000 to 2,499 grams; or
9 — 2,500 grams and over.
The coding note under code 765.1 states that prematurity usually implies a birth weight of 1,000 to 2,499 grams. According to the coding note under code 765.0, extreme immaturity usually implies a birth weight of less than 1,000 grams. However, the use of code 765.0 or 765.1 is not based on birth weight. Code assignment is based on physician documentation of the diagnosis. “Codes from 764-765 categories are not based on weight alone, but on the clinical assessment of the maturity of the infant” (AHA Coding Clinic for ICD-9-CM, 1991, second quarter, page 19).
When the physician documents prematurity or extreme immaturity, a code from subcategory 765.2, Weeks of gestation, should also be assigned. Code 765.2x should not be assigned on all newborn records; it should only be assigned as a secondary diagnosis when the newborn infant is diagnosed with extreme immaturity (765.0x), prematurity (765.1x), or slow fetal growth and malnutrition (category 764) (AHA Coding Clinic for ICD-9-CM, 2002, fourth quarter, pages 63-64). Code 765.2 requires one of the following fifth-digit subclassifications:
765.20 — Unspecified weeks of gestation;
765.21 — Less than 24 completed weeks of gestation;
765.22 — 24 completed weeks of gestation;
765.23 — 25 to 26 completed weeks of gestation;
765.24 — 27 to 28 completed weeks of gestation;
765.25 — 29 to 30 completed weeks of gestation;
765.26 — 31 to 32 completed weeks of gestation;
765.27 — 33 to 34 completed weeks of gestation;
765.28 — 35 to 36 completed weeks of gestation; or
765.29 — 37 or more completed weeks of gestation.
Signs and Symptoms
The difficulties may not appear until later in childhood or even until adulthood. These types of complications would be coded on the child’s record, not the mother’s.
Coding and sequencing for prematurity are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.
— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to nearly 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com or by calling 800-367-2447.