Abnormal findings on antenatal screening of mother

Coding Tips,

The ICD-10 O28 code series are used to describe abnormal findings on antenatal screening of mother as a reason for an encounter. The series includes O28.0 – O28.9. In order to better understand the O28 code series, the corresponding ICD-10 descriptors along with some additional notes and examples are provided:

 • O28.0: Abnormal hematological finding on antenatal screening of mother. Notes: This descriptor notes that an abnormal maternal blood test finding that for instance could potentially result in a known or suspected fetal condition. This code is not necessarily for a blood test that a consultative MFM physician would order, but it might be paired as an indication to perform ultrasound anatomical procedures, doppler velocimetry, fetal echocardiography, or other indicated procedure.

 • O28.1: Abnormal biochemical finding on antenatal screening of mother. Notes: This code would be used to report a finding of abnormal MSAFP or other biochemical marker, which may be an indication to evaluate fetal anatomy or performance of other procedures.

 • O28.2: Abnormal cytological finding on antenatal screening of mother.

 • O28.3: Abnormal ultrasonic finding on antenatal screening of mother. Note: This descriptor covers many possible abnormal ultrasound findings, such as single umbilical artery, EIF, CPC, echogenic bowel.

 • O28.4: Abnormal radiological finding on antenatal screening of mother. Note: If an abnormal maternal finding is present, such as on diagnostic imaging of a maternal structure, this is an applicable diagnosis code. 

 • O28.5: Abnormal chromosomal and genetic finding on antenatal screening of mother. Note: This code would be used to report abnormal genetic screening results, such as abnormal aneuploidy screening. 

 • O28.8: Other abnormal findings on antenatal screening of mother.

 • O28.9: Unspecified abnormal findings on antenatal screening of mother.

 
The above diagnosis codes are not typically enough to establish medical necessity. Instead, it is recommended a code from the O35.0XX0-O35.9XX9 series precede codes from O28.0-O28.9. The O35 series denotes maternal care for known or suspected fetal abnormality and damage.  In addition, the O36.0XX0 - series may also be applicable.

Below is an example that summarizes the use of ICD-10 codes O28.0-O28.9:

 A 33-year-old G2P1001 female at 23 weeks gestation presenting for an initial MFM consultation and ultrasound with an abnormal Quad screen and noted to have a shortened femur length on today's targeted fetal anatomy survey.

The suspected chromosomal abnormality due to abnormal QUAD screen, with current ultrasound finding of short femur would be coded as follows:

-        O35.1XX0  Maternal care for (suspected) chromosomal abnormality in fetus

-        O28.5         Abnormal chromosomal and genetic finding on antenatal screening of mother

-        O36.5920   Maternal care for other known or suspected poor fetal growth, second trimester

-        Z3A.23       23 weeks gestation

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