A: Post-dates pregnancy is any pregnancy that is 40 weeks or more. In the index, post-dates pregnancy has a nonessential modifier for 40-42 weeks. Code O48.0 should be used for a patient who is 40 weeks, 0 days.
Q: O13.1 seems to be for gestational hypertension in the first trimester, but it was stated that there is no code for gestational hypertension in the first trimester, because it would be considered pre-existing hypertension. I feel we are missing something somewhere!
A: There are codes for pre-existing hypertension in the first trimester, however there are not codes for pre-eclampsia (O14.9-) in the first trimester because it is not diagnosed as such until at least the second trimester.
Q: O42 is for premature rupture of membranes, onset of labor. It doesn’t have anything to do with how long the patient was ruptured before delivery, only how long the patient was ruptured before onset of labor. We recently had an outside audit, and they showed this one as an error for us as well. It seems we could use more clarification on how we are seeing that code.
A: The codes in category O42 describe preterm premature rupture of membranes (PPROM), which is ROM before 37 completed weeks as well as premature rupture of membranes (PROM), which is ROM before the onset of labor in a term pregnancy. Codes in subcategory O42.0 are used when onset of labor occurs within 24 hours of rupture. Codes in subcategory O42.1 are used when onset of labor is more than 24 hours after rupture. If the length of time between ROM and onset of delivery is not specified, codes in subcategory O42.9 are used.
Q: We also code Ambulance accounts, and generally put symptoms on for when they are coming to the hospital first. If a patient comes by ambulance with a completely normal pregnancy, is only taking the ambulance because she is in labor, and the baby is NOT born in the ambulance, what code would be used? We really liked the chart on page 23, but it doesn’t quite address that particular scenario.
A: For a patient being taken to the hospital in an ambulance to deliver, assign a code from category Z34, Encounter for supervision of normal pregnancy.
Q: I have a question about outpatient obstetric visits where the patient was sent for a NST from their provider’s office due to an abnormal BPP. For example, the chief complaint is that the patient was sent from their OB visit because she had a score of 6/8 on her BPP with two points off for breathing. Our physician documents that the NST was performed and was reactive. How would you code the admit and first listed diagnosis?
A: Assign code O28.8, Other abnormal findings on antenatal screening of mother. A biophysical profile (BPP) test combines ultrasound and fetal nonstress test and is usually performed when there is an increased risk of pregnancy loss due to conditions, such as multiparity, diabetes, postterm pregnancy, or decreased fetal movements.
Q: Do you code all O codes on every routine visit even if the provider does not address the issue? Example, if a patient has depression in pregnancy, but the provider does not discuss their depression during the visit would you still code the O99.34- code or leave it off the claim since it was not addressed? Or if a patient has obesity complicating pregnancy?
A: The logic used for coding for prenatal visits combines several guidelines.
First, Guideline I.C.15.b.1. states that for routine prenatal visits when no complications are present, a code from category Z34, Encounter for supervision of normal pregnancy, should be coded as first-listed diagnosis. These codes should not be reported in addition to Chapter 15 codes. If complications are present, codes from Chapter 15 should be used rather than code Z34.-.
Second, OCG IV.G. states to list first the ICD-10-CM code for the diagnosis, condition, problem, or other reason for the encounter that is chiefly responsible for the services provided. Any additional codes may be assigned for coexisting conditions. Chronic conditions treated on an ongoing basis may be coded and reported as many times as the patient receives treatment and care for the condition (OCG IV.I.). If a condition is present but was not addressed during the encounter, it would not normally be coded. However, chronic conditions that always impact the pregnancy should be reported. According to Coding Clinic, Fourth Quarter 2018: Page 77, obesity and morbid obesity are always clinically significant and reportable when documented by the provider. Other chronic conditions that would be considered clinically significant during pregnancy, even if not directly addressed, include diabetes and hypertension. When the patient is on medications for other conditions and the clinical significance is not known (e.g., depression), query the provider to determine if the condition should be reported.
Q: If the mother is A- would you only code the Z67.11?
A: Codes for blood type status are available as additional diagnoses to provide more detail about the patient. These codes should not be used as a primary diagnosis. While there are no restrictions on the use of this code, Haugen Consulting Group (HCG) does not recommend assigning this code unless the patient is specifically being seen for blood type incompatibility with the fetus. This code can also be used in addition to an isoimmunization code or to provide additional information about blood incompatibility, if documented.
Q: If a patient has had a previous C-Section scar, would you code O34.219 on every OB visit?
A: During a routine prenatal visit, do not code for a previous c-section scar unless its clinical significance is noted by the provider. A previous c-section can cause feto-maternal complications in subsequent pregnancies, but the concern for such complications should be documented by the provider to justify code assignment.
Q: If the patient develops a condition that is typically considered chronic while pregnant, do we count that as a chronic for the new 2021 E/M changes? Example, a patient develops GDM.
A: CPT defines “chronic” as follows:
Stable, chronic illness: A problem with an expected duration of at least one year or until the death of the patient. For the purpose of defining chronicity, conditions are treated as chronic whether or not stage or severity changes (e.g., uncontrolled diabetes and controlled diabetes are a single chronic condition). “Stable” for the purposes of categorizing MDM is defined by the specific treatment goals for an individual patient. A patient who is not at his or her treatment goal is not stable, even if the condition has not changed and there is no short-term threat to life or function. For example, in a patient with persistently poorly controlled blood pressure for whom better control is a goal is not stable, even if the pressures are not changing and the patient is asymptomatic, the risk of morbidity without treatment is significant. Examples may include well-controlled hypertension, noninsulin- dependent diabetes, cataract, or benign prostatic hyperplasia
Based on this definition, GDM or anything that is restricted to the gestational period would not be considered chronic.
Q: Do you code the condition to the trimester the condition started? For example I have a patient in for their 34 week appointment and they developed anemia in 2nd trimester. Do I still code O99.012 or would I code O99.013 since the patient is currently in their 3rd trimester?
A: Guideline I.C.15.a.4. states, “If the condition developed prior to the current admission/encounter or represents a pre-existing condition, the trimester character for the trimester at the time of the admission/encounter should be assigned.”
Q: Do the SROM codes pertain to spontaneous or induced onset of labor? Our providers do not give us the interval from SROM to onset of labor.
A: The codes for delayed delivery following rupture of membranes differentiate between amniotomy performed for induction of labor (artificial rupture of membranes or AROM) and spontaneous rupture of membranes (SROM).
Delayed delivery following AROM is reported with code O75.5, Delayed delivery after artificial rupture of membranes.
The codes for premature rupture of membranes (PROM) are based on the onset of labor and whether the pregnancy is preterm (before 37 weeks completed gestation). If documentation does not specify the length of time between SROM and onset of labor, assign code O42.9-, Premature rupture of membranes, unspecified as to length of time between rupture and onset of labor.
Q: I'm at a total loss with the whole Mom-Rh negative / NB-Rh positive issue. I haven't been coding on either mom or NB if provider documents adequate coverage. My research has not been very helpful either. Usually all I have to go on is blood type -/+ on both charts. Is that enough or do I need to dig deeper (labs in antepartum perhaps)? And is it automatically coded because it's mentioned? Thanks for any clarification you can provide, or direction to a resource to clear up my confusion!
A: You should not code Rh isoimmunization based on documentation only of Rh-negative status. Just because the patient has an Rh-negative blood type done not mean that the patient has isoimmunization. If you there is documentation that anti-D immune globulin was administered and there is not clear documentation of why it was given (treatment of isoimmunization vs. prophylactic measure), query the physician. Remember, according to Coding Clinic, it is inappropriate to use documentation from previous encounters for coding purposed (CC, 3rd Quarter 2013, page 27).
Q: You mentioned that you cannot code Rh isoimmunization just because RhoGAM is given, but can you code the procedure code for prophylactic administration?
A: Yes, you can code the procedure code for administration of the Rh immune globulin when it is given, whether it is therapeutic or prophylactic.
Q: How do you code for sepsis due to COVID-19 in a pregnant patient? Does that require one or multiple O codes for the infection?
A: Sepsis due to COVID-19 in pregnancy requires 2 O codes. Assign the following codes:
- 81-, Other maternal infectious and parasitic diseases complicating pregnancy, childbirth, and the puerperium
- 89, Other specified sepsis
- 512, Diseases of the respiratory system complicating pregnancy, childbirth, and the puerperium
- 1, COVID-19
Updated 3/21/22
Q: How would you code “Placenta- anterior w/a marginal cord insertion”. Several of us coders are coming up with O43193 and others are saying O6989X0. Would really appreciate your thoughts.
A: Assign code O43.19-, Other malformation of placenta for a marginal cord insertion. This is a condition in which the umbilical cord attaches to the edge, rather than the middle of the placenta and represents a malformation of the placenta rather than a problem with the cord itself. This is similar to a velamentous insertion of the UC, in which the cord attaches to other membranes in the uterus rather than the placenta. Velamentous insertion is also coded category O43.

Kristi Pollard, RHIT, CCS, CPC, CIRCC, AHIMA-Approved ICD-10-CM/PCS Trainer
Senior Consultant
Kristi also performs DRG and APC audits and is known for her vast knowledge on coding vascular interventional radiology procedures. Kristi has an extensive background in coding education and consulting and is a national speakers on topics related to ICD-10 and CPT coding as well as code-based reimbursement.