There are some significant differences between ICD-9 and ICD-10-CM for coding conditions related to pregnancy, childbirth and the puerperium. Coding for multiple gestation, for example, requires documentation related to the number of fetuses, the number of placentae and the number of amniotic sacs. This information is indicated in ICD-9-CM using the multiple gestation codes in category 651 to capture the number of fetuses and supplementary codes in category V91 to capture the multiple gestation placenta status. In ICD-10-CM, the same information is indicated using a combination code from category O30.

Under category code O30, there is also a note to code any complication of multiple gestation. One key difference between ICD-9-CM and ICD-10-CM relates to multiple gestation and the need to assign a seventh character identifying the fetus for certain code categories and subcategories. The following categories/subcategories require identification of the fetus:

  • O31 Complications specific to multiple gestation
  • O32 Maternal care for malpresentation of fetus
  • O33.3 Maternal care for disproportion due to outlet contraction of pelvis
  • O33.4 Maternal care for disproportion of mixed maternal and fetal origin
  • O33.5 Maternal care for disproportion due to unusually large fetus
  • O33.6 Maternal care for disproportion due to hydrocephalic fetus
  • O35 Maternal care for known or suspected fetal abnormality and damage
  • O36 Maternal care for other fetal problems
  • O40 Polyhydramnios
  • O41 Other disorders of amniotic fluid and membranes
  • O60.1 Preterm labor with preterm delivery
  • O60.2 Term delivery with preterm labor
  • O64 Obstructed labor due to malposition and malpresentation of fetus
  • O69 Labor and delivery complicated by umbilical cord complications

All of the above categories require a seventh character to identify the fetus to which the complication code applies. The seventh-character extensions identifying the fetus are as follows:

  • 0 for unspecified Fetus/not applicable
  • 1 for Fetus 1
  • 2 for Fetus 2
  • 3 for Fetus 3
  • 4 for Fetus 4
  • 5 for Fetus 5
  • 9 for other Fetus

For single gestation or when documentation is insufficient to identify the fetus, the seventh character “0” for “not applicable/unspecified” is assigned. For multiple gestations, again, each fetus should be identified with a number (Fetus 1, Fetus 2, Fetus 3, etc.). The fetus or fetuses affected by a condition then should be documented using the number assigned to the fetus. For example, a triplet gestation in the third trimester – with Fetus 1 having no complications, Fetus 2 with a separate placenta/amniotic sac having polyhydramnios, and Fetus 3 also in a separate placenta/amniotic sac having hydrocephalus with maternal pelvic disproportion – would require reporting of the complications as follows:

Fetus 1 – No codes

Fetus 2 – O40.3xx2, Polyhydramnios, third trimester, Fetus 2

Fetus 3 – O33.6xx3, Maternal care for disproportion due to hydrocephalic fetus, Fetus 3.

An additional combination code identifying the triplet pregnancy and placenta status would also be reported.

Consider the following two examples:

Example 1: A 31-year-old G4 P1111 black female is being followed for known anti-U isoimmunization. The patient has an 8-year-old daughter delivered via SVD at 38 weeks. Her obstetric history also includes a spontaneous abortion at 14 weeks and a stillbirth at 32 weeks, at which time the anti-U isoimmunization was identified. Anti-U serum titer has been monitored throughout the pregnancy. She is now at 30 weeks and anti-U serum titer is elevated at 1:1025. She is being seen today to discuss the results of her blood test. The need to monitor amniotic fluid bilirubin using serial amniocentesis so that hemolytic anemia in the fetus can be evaluated and treated, if needed, is also discussed. Her first amniocentesis is scheduled for tomorrow and amniocentesis will be repeated at two-week intervals.

ICD-10-CM Codes:

O36.1930 Maternal care for other isoimmunization, third trimester, fetus not applicable or unspecified

Z3A.30 30 weeks gestation of pregnancy


Category O36 requires a seventh-character extension for identification of the fetus. Identification of the fetus only applies for multiple gestations. Since this is a single gestation, the seventh-character extension is 0, which indicates that identification of the affected fetus is not applicable.

Example 2: The patient is a 33-year-old primipara with a triplet gestation at 27 weeks who presents for NST/BPP with perinatologist. Weight is 138, a four-pound gain in two weeks. HR 88, RR 12. Verified is a triplet gestation, with Fetus 1 and Fetus 2 sharing a single placenta and separate amniotic sacs. Fetus 1 is a 660-gram female with a crown-to-heel length of 31 cm. She is active with good FHR variability. Fetus 2 is a 720-gram female with a crown-to-heel length of 33 cm. She is also active with good FHR variability. Amniotic fluid is adequate. Placenta is high on the right side of the uterus. Fetus 3 is a male, approximately 360 grams and 26.5 cm in length. There is very little amniotic fluid in the sac. Placenta is small in size. FHR is 160 with no variability and very little fetal movement noted. Patient is scheduled for admission to antepartum unit for observation and monitoring. She is cautioned that the findings today are not favorable for Fetus 3 and delivery of all three babies may be necessary in the next day or two. Betamethasone IM is administered to stimulate fetal lung maturity. The patient’s husband is present, and questions are answered. Perinatology fellow will accompany family to floor. Impression: triplet gestation at 27 weeks with poor fetal growth of Fetus 3 due to placental insufficiency. Normal fetal growth for Fetus 1 and Fetus 2.

ICD-10-CM Codes:

O36.5123 Maternal care for known or suspected placental insufficiency, second trimester, Fetus 3

O41.02×3 Oligohydramnios, second trimester, Fetus 3

O30.112 Triplet pregnancy with two or more monochorionic fetuses

Z3A.27 27 weeks gestation of pregnancy


The seventh character identifies the fetus affected by the condition or complication, not the number of fetuses affected. In this case only one fetus is affected by the two identified complications, oligohydramnios and placental insufficiency, so codes for these conditions are assigned with the seventh character “3” because this fetus has been identified on the ultrasound as Fetus 3. If more than one fetus was affected, the codes for each condition would be listed again for each fetus affected by the respective conditions.

About the Author

Lauri Gray, RHIT, CPC, has worked in the health information management field for 30 years. She began her career as a health records supervisor in a multi-specialty clinic. Following that she worked in the managed care industry as a contracting and coding specialist for a major HMO. Most recently she has worked as a clinical technical editor of coding and reimbursement print and electronic products. She has also taught medical coding at the College of Eastern Utah. Areas of expertise include: ICD-10-CM, ICD-10-PCS, ICD-9-CM diagnosis and procedure coding, physician coding and reimbursement, claims adjudication processes, third-party reimbursement, RBRVS and fee schedule development. She is a member of the American Academy of Professional Coders (AAPC) and the American Health Information Management Association (AHIMA).

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