ICD-10 essentials for busy physicians who would rather be doing something else -- OB GYN

Last blog I talked about a couple of things you can do to create a manageable ICD-10-based cheat sheet for OB codes if you are so inclined. But I didn’t talk directly about differences between ICD-9 and ICD-10 obstetrics coding and documentation, and I haven’t discussed non-OB female coding and documentation at all. So here goes.

The biggest single difference in the classification of obstetrics encounters is that in ICD-9 they were classified according to whether the patient delivered during the encounter or not.  In ICD-10, antepartum encounters are classified by the trimester of the pregnancy at the time of the encounter. Documenting for trimester is a done deal: You of course document first thing how many weeks’ gestation on a pregnant patient’s history and physical, from which the trimester is easily derived. Trimester does not need to be explicitly documented to use these codes.

Here is a typical example of an antepartum diagnosis specifying trimester of pregnancy:

O13.1 Gestational [pregnancy-induced] hypertension without significant proteinuria, first trimester 
O13.2 Gestational [pregnancy-induced] hypertension without significant proteinuria, second trimester 
O13.3 Gestational [pregnancy-induced] hypertension without significant proteinuria, third trimester


642.33 Transient hypertension of pregnancy, antepartum condition or complication

In cases where a condition arises during labor or occurs in the postpartum period, the relevant codes are classified that way. Below are examples of a condition arising during labor and one occurring after delivery. Keep in mind that the word “complication” as used in both ICD-9 and ICD-10 obstetrics codes casts no aspersions whatsoever on the quality of care. Anything other than a completely uneventful pregnancy in a perfectly healthy woman is by definition a complication of the pregnancy. Gestational hypertension is obviously a complication of the pregnancy, but so is pre-existing hypertension, asthma, obesity, smoking -- in short, anything including a broken wrist is coded as a complication of pregnancy unless you document that the condition is incidental to the pregnancy.

O75.81 Maternal exhaustion complicating labor and delivery


669.81 Other complications of labor and delivery, delivered, with or without mention of antepartum condition
669.82 Other complications of labor and delivery, delivered, with mention of postpartum complication

O86.12 Endometritis following delivery  


670.12 Puerperal endometritis, delivered, with mention of postpartum complication 
670.14 Puerperal endometritis, postpartum condition or complication

ICD-10 has added some useful detail in other areas. For instance, there are unique codes for the different types of Rh incompatibility for anti-D and anti-A antibodies. There are also more specific codes for genitourinary infections occurring in pregnancy that specify the site of the infection, like O23.12 Infections of bladder in pregnancy, second trimester. There is also a specific code for Strep B carrier, to be recorded during the encounter for delivery when prophylactic measures are usually taken for such patients: O99.824 Streptococcus B carrier state complicating childbirth.

As we have seen in other chapters, this version of the ICD got rid of codes that use obsolete terminology. The same is true here. ICD-10 discontinued the codes from way back when that specified whether an abortion was legal, illegal or unspecified, and instead focuses on conditions associated with an abortion, such as O03.38 Urinary tract infection following incomplete spontaneous abortion.

GYN diagnosis codes
Frankly, not a lot to report here. There are 188 ICD-9 diagnosis codes specific to the non-obstetric female reproductive system and 225 ICD-10 codes. The increased detail is easily accounted for in a few places, like anatomic site detail, causative organism, and so forth. There are areas where laterality matters, such as the breast disorder example below.

N60.11 Diffuse cystic mastopathy of right breast 
N60.12 Diffuse cystic mastopathy of left breast 
N60.19 Diffuse cystic mastopathy of unspecified breast


610.1 Diffuse cystic mastopathy

In addition, there are a few areas where specific anatomic sites have been added. Here is an example.

N76.0 Acute vaginitis
N76.1 Subacute and chronic vaginitis 
N76.2 Acute vulvitis 
N76.3 Subacute and chronic vulvitis


616.10 Vaginitis and vulvovaginitis, unspecified

In other cases, the organism responsible for an infection is specified in the code. For example, A56.11 Chlamydial female pelvic inflammatory disease and A56.02 Chlamydial vulvovaginitis are both new codes in the infectious disease chapter.

This is not exactly the stuff of CNN Headline News, but why should it be? It is an upgrade to a system of information cataloging, after all. When our libraries switched from Dewey Decimal to Library of Congress, nobody had to call out the National Guard. It would be lovely if the switch to ICD-10 becomes similarly uneventful once we have a final implementation date and people focus on the work.

Rhonda Butler is a senior clinical research analyst with 3M Health Information Systems. She is responsible for the development and maintenance of the ICD-10 Procedure Coding System since 2003 under contract to CMS, and for the development and maintenance of the ICD-10 General Equivalence Mappings (GEMs) and Reimbursement Mappings under contract to CMS and the CDC.  She leads the 3M test project to convert the MS-DRGs to ICD-10 for CMS, and is on the team to convert 3M APR-DRGs to ICD-10. Rhonda also writes for the 3M Health Information Systems blog.