Diseases of the nervous sys comp pregnancy, unsp trimester

This code signifies a neurological disorder that is present or arises during a pregnancy, impacting the mother's health. It covers conditions affecting the brain, spinal cord, or peripheral nerves that are exacerbated by or directly related to the gravid state. The specific trimester of pregnancy is not documented or is unknown.

Apply this code when a pregnant patient presents with a nervous system disease, such as epilepsy, multiple sclerosis, or Bell's palsy, and the medical record does not specify the trimester. Documentation should clearly link the neurological condition to the pregnancy, even if the exact trimester is not explicitly stated.

• Always sequence the obstetric code (from category O09-O9A) as the primary diagnosis, followed by this code.
• Avoid using this code if the documentation specifies the trimester; instead, use the more specific O99.351, O99.352, or O99.353.
• Ensure the medical record supports the causal link between the neurological condition and the pregnancy, not just a co-occurrence.