How Is “Threatened Labor” Coded? O47 False Labor, Not O60 Preterm Labor

“Threatened labor” has no code of its own, and it does not need one: category O47, False labor, carries an Includes note listing “Braxton Hicks contractions” and “threatened labor.” An Includes note defines what the category covers, so threatened labor is false labor for classification purposes.

Category O60, Preterm labor, confirms it from the other side with an Excludes1: “false labor (O47.0-)” and “threatened labor NOS (O47.0-).” The two categories cannot both apply — O47 in turn carries an Excludes1 for preterm labor (O60.-) — and the record decides which: O60 includes “onset (spontaneous) of labor before 37 completed weeks of gestation,” so O60.0- requires the provider to document that labor began. If the note says the labor was threatened, or false, and did not begin, the code is O47.0-.

The general rule in Section I.B.11 points the same way. For a condition described as “impending” or “threatened” at discharge: “If it did occur, code as confirmed diagnosis. If it did not occur, reference the Alphabetic Index to determine if the condition has a subentry term for ‘impending’ or ‘threatened’ … If the subterms are listed, assign the given code.” Here the tabular has already done the work — the subentry lands on O47.

O47 splits on 37 completed weeks: O47.0- before 37 weeks, O47.1 at or after 37 weeks, O47.9 unspecified. O47.0- then takes a trimester character — O47.00 unspecified trimester, O47.02 second, O47.03 third. There is no first-trimester code; the chapter guideline explains that “certain codes have characters for only certain trimesters because the condition does not occur in all trimesters.”

The trimester character comes from the record, not from arithmetic the coder does on their own: “Assignment of the final character for trimester should be based on the provider’s documentation of the trimester (or number of weeks) for the current admission/encounter. … The provider’s documentation of the number of weeks may be used to assign the appropriate code identifying the trimester.” The trimester timeframes are stated at the head of Chapter 15.

A Z3A weeks-of-gestation code may be added: category Z3A codes “may be assigned to provide additional information about the pregnancy,” and are not used for abortive outcomes, elective termination or postpartum conditions.

• Preterm labor without delivery, O60.0-. Labor began before 37 weeks and was stopped or resolved without delivery. Requires documented onset of labor; otherwise it is O47.0-.
• Threatened abortion, O20.0. A different event entirely: bleeding in early pregnancy — category O20 covers hemorrhage before completion of 20 weeks — with the inclusion term “Hemorrhage specified as due to threatened abortion.” “Threatened” here modifies abortion, not labor, and the code sits in a different block.

1. Confirm the documentation: “threatened labor” or “false labor” with no onset of labor → O47; documented onset of labor before 37 weeks → O60.
2. Pick the O47 subcategory by weeks: before 37 completed weeks O47.0-, at or after 37 weeks O47.1, unspecified O47.9.
3. Assign the trimester character from the provider’s documented trimester or weeks (O47.00 / .02 / .03).
4. Add a Z3A weeks-of-gestation code if documented.
5. Do not confuse with threatened abortion, O20.0, in early pregnancy.

1. “Threatened preterm labor,” 30 weeks, contractions resolved, no cervical change documented as labor. O47.03 (third trimester) plus the Z3A.30 weeks code if documented.
2. Preterm labor documented as begun at 32 weeks, stopped without delivery. O60.03 — labor began, so O47 does not apply.
3. Bleeding at 10 weeks documented as threatened abortion. O20.0 — a different event and block.

• O60 for threatened labor with no documented onset of labor.
• O47.0- with an invented first-trimester character — none exists.
• Trimester assigned by the coder’s arithmetic rather than the provider’s documentation.
• O20.0 confused with O47.

• Whether labor actually began (O60) or was threatened/false (O47).
• Gestational age in weeks or trimester, from the provider.
• Whether the event is bleeding in early pregnancy (O20.0) rather than labor.