Pre-Existing or Gestational?

by  Chris Woolstenhulme, QCC, CMCS, CPC, CMRS
February 1st, 2018

It is important to make a clear distinction between pre-existing conditions and conditions brought on by the pregnancy (gestational) or pregnancy related conditions.

1. Condition Detail: Was the condition pre-existing (i.e., present before pregnancy)?
2. Trimester: When did the pregnancy-related condition develop?
3. Casual Relationship: Establish the relationship between the pregnancy and the complication (e.g., preeclampsia)

Code examples:

• O99.011 Anemia complicating pregnancy, first trimester
• O13.2  Gestational [pregnancy-induced] hypertension without significant proteinuria, second trimester
• O24.012 Pre-existing diabetes mellitus, type 1, in pregnancy, second trimester
• O10.02 Pre-existing essential hypertension complicating childbirth
• O21.2 Late vomiting of pregnancy - Excessive vomiting starting after 20 completed weeks of gestation

Be sure to look for coding notes. "Use additional code," for example, requires you report a code from I15- to identify the type of secondary hypertension. If the patient has pre-existing diabetes mellitus, identify any insulin use (Z79.4). Do not use this code if the patient has gestational diabetes, as this code is for long-term use.

Take a look at another example of a pre-existing condition and the notes associated with this code:

O34.41 Maternal care for other abnormalities of cervix, first trimester

• Includes: the listed conditions as a reason for hospitalization or other obstetric care of the mother, or for cesarean delivery before onset of labor
• Code First: any associated obstructed labor (O65.5)
• Use additional code for specific condition

These instructions are not optional. They must be included in your documentation and coding to ensure proper reimbursement.