On a US labor floor, the nurse who watches the tracing continuously is trained through AWHONN, and the obstetric clinician who makes many management decisions is guided by ACOG. Both begin with the 2008 NICHD definitions, but emphasis, interpretation, documentation, escalation and recommended response can diverge. The 2025 ACOG guideline frames surveillance as fetal heart rate monitoring: of six uterine parameters that global guidelines (FIGO, NICE, the International CTG Consensus) define, it defines only tachysystole, and it links action to fetal heart rate change rather than to abnormal uterine activity itself. Category II, the indeterminate category, filled 39.1% of tracing time in the last two hours before birth in 48,444 term labors, which is where a shared language matters most. The pattern is not unique to medicine: NASA lost the Mars Climate Orbiter in 1999 when one team reported thruster data in pound-force seconds and another expected newton-seconds, as the shared specification required, while working-level concerns were raised informally and never resolved. In 2004 the Joint Commission found communication issues as a root cause in 72% of 47 reported perinatal deaths and permanent injuries and recommended standardized terminology for all clinicians. The tracing belongs to two patients, the fetus and the pregnant woman. One team needs one language, one set of operational definitions for uterine and fetal signals, and one escalation pathway understood identically by everyone at the bedside.
Scene-by-scene transcript
0 to 6 s. Title: One team. Two languages. Why the US labor floor needs one fetal monitoring language.
6 to 16 s. One team at the bedside, two languages. The nurse at the bedside observes the tracing continuously and is trained by AWHONN. The obstetric clinician makes many of the management decisions and is guided by ACOG. One team, one patient. "It's like having two medical records where one does not read the other."
16 to 26 s. Shared words, then two conversations. Both start with the 2008 NICHD definitions: baseline, variability, accelerations, decelerations, Category I, II and III. Nursing and obstetrics can then diverge in emphasis, interpretation, documentation, escalation and recommended response.
26 to 42 s. It has happened before: one mission, two languages. Lockheed Martin's ground software reported thruster impulse in pound-force seconds; JPL navigation expected newton-seconds, as the interface specification required. With no conversion, every firing read 4.45 times too weak. Planned closest approach 226 km; after-the-fact estimate about 57 km; 80 km was the survivable minimum (schematic). Mars Climate Orbiter was lost on 23 September 1999.
42 to 58 s. Sound familiar? Two teams: Lockheed Martin and JPL; nursing and obstetrics. A shared standard: the newton-second specification; the 2008 NICHD definitions. Where it split: pound-force versus newton-seconds; emphasis, escalation and response. Warning signs: raised informally, by e-mail, and unresolved; communication a root cause in 72% of perinatal sentinel events. The fix: empower everyone to elevate concerns; one language and one escalation pathway. One mission, two languages, nobody translated. A spacecraft can be replaced. A child cannot.
58 to 70 s. The US narrowed two signals to one. Global guidelines use cardiotocography, two signals, with the pregnant and fetal patient as one physiologic system. The 2025 US guideline uses "fetal heart rate monitoring"; its surveillance object is the fetal heart rate, and uterine activity serves mainly as a timing reference and a count.
70 to 84 s. Uterine activity, what each standard defines. Global guidelines define contraction shape and symmetry, duration, resting tone, relaxation interval, and tachysystole; hypertonus or prolonged contraction is defined in some guidelines. The US guideline defines only tachysystole: 1 of 6. It acts on tachysystole when fetal heart rate changes appear, not as an independent trigger.
84 to 94 s. Where the tracings actually live. In 48,444 term labors, Category I was present 77.9% and Category II 22.1% of labor time; in the last 2 hours before birth, 60.9% and 39.1%. Category III was under 0.01%. Category II is indeterminate, and it is exactly where nurse and obstetrician must agree on what they see and what happens next.
94 to 108 s. Preventive versus reactive (schematic). As contractions become more frequent, fetal oxygen saturation falls. Global guidelines act when uterine activity becomes abnormal; the US guideline acts after the fetal heart rate changes. Measured fetal oxygen saturation fell 20% with 5 contractions per 10 minutes and 29% with 6 or more (oxytocin, 56 women). The uterus signals first.
108 to 118 s. This is a patient-safety problem. In 47 perinatal deaths and permanent injuries reported to the Joint Commission, communication issues were a root cause in 72%, the most common; inadequate fetal monitoring in 34%. In 2004 the Joint Commission recommended educating nurses, residents, nurse midwives and physicians to use standardized terminology to communicate abnormal fetal heart rate tracings.
118 to 126 s. A fetal heart rate tracing belongs to neither nursing nor obstetrics. It belongs to two patients, the fetus and the pregnant woman. Professional responsibility runs to the pregnant patient and the fetal patient, not to a discipline.
126 to 140 s. One team. One language. One set of operational definitions, uterine and fetal. Read contractions and fetal heart rate as one system. One escalation pathway, understood identically by everyone at the bedside. Train nurses, midwives, residents and obstetricians together. Teaching clinicians to interpret tracings is important. Teaching the entire team to interpret, communicate and act on them in the same way is the patient-safety objective. Guideline comparison shows differences in structure; it cannot by itself show differences in outcomes.
140 to 144 s. Evidence, Animated. ObGyn Intelligence. Evidence Matters.
Publications used in this film
Grünebaum A, Dudenhausen J, Chervenak FA. Global and US standards for intrapartum surveillance of the pregnant and the fetal patient. Int J Gynecol Obstet. 2026. Epub ahead of print. doi:10.1002/ijgo.71084 Guideline comparisonTables 1 to 3: uterine definitions, surveillance object, preventive versus reactive management.
American College of Obstetricians and Gynecologists. ACOG Clinical Practice Guideline No. 10: Intrapartum fetal heart rate monitoring: interpretation and management. Obstet Gynecol. 2025;146(4):583-599. doi:10.1097/AOG.0000000000006049 GuidelineUS comparator.
National Institute for Health and Care Excellence. Fetal monitoring in labour. NICE guideline NG229. London: NICE; 2022. Available from: https://www.nice.org.uk/guidance/ng229 Guideline
Chandraharan E, Pereira S, Ghi T, Gracia Perez-Bonfils A, Fieni S, Jia YJ, et al. International expert consensus statement on physiological interpretation of cardiotocograph (CTG): first revision (2024). Eur J Obstet Gynecol Reprod Biol. 2024;302:346-355. doi:10.1016/j.ejogrb.2024.09.034 Consensus statement
Macones GA, Hankins GDV, Spong CY, Hauth J, Moore T. The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines. Obstet Gynecol. 2008;112(3):661-666. doi:10.1097/AOG.0b013e3181841395 DefinitionsShared starting vocabulary and the three-tier categories.
Jackson M, Holmgren CM, Esplin MS, Henry E, Varner MW. Frequency of fetal heart rate categories and short-term neonatal outcome. Obstet Gynecol. 2011;118(4):803-808. doi:10.1097/AOG.0b013e31822f1b50 Observational48,444 term labors, 10 hospitals; time spent in each category.
Simpson KR, James DC. Effects of oxytocin-induced uterine hyperstimulation during labor on fetal oxygen status and fetal heart rate patterns. Am J Obstet Gynecol. 2008;199(1):34.e1-34.e5. doi:10.1016/j.ajog.2007.12.015 ObservationalFetal SpO2 fell 20% and 29% with hyperstimulation (56 women).
The Joint Commission. Sentinel Event Alert Issue 30: Preventing infant death and injury during delivery. Oakbrook Terrace (IL): The Joint Commission; 2004 Jul 21. Root cause analyses47 reported cases, 1996 to 2004; root causes self-reported by organizations.
National Aeronautics and Space Administration. Mars Climate Orbiter Mishap Investigation Board Phase I report. Washington (DC): NASA; 1999 Nov 10. Available from: https://llis.nasa.gov/llis_lib/pdf/1009464main1_0641-mr.pdf Mishap investigationRoot cause: pound-force seconds instead of the specified newton-seconds. Contributing cause 5: inadequate communication between project elements; concerns handled by e-mail rather than formal problem resolution.
Chervenak FA, McCullough LB. The professional responsibility model of obstetric ethics and caesarean delivery. Best Pract Res Clin Obstet Gynaecol. 2013;27(2):153-164. doi:10.1016/j.bpobgyn.2012.09.001 EthicsObligations to the pregnant patient and the fetal patient.
Association of Women's Health, Obstetric and Neonatal Nurses. World Heart Day post on the AWHONN Fetal Heart Monitoring Program. LinkedIn. 2026 Sep 29. Commentary
Grünebaum A. Comment on the AWHONN World Heart Day post. LinkedIn. 2026 Sep 29. CommentarySource of the two-records analogy, the divergence points, and the closing objective.
Version 1.0, 29 September 2026. Traces and trajectories in scenes 2, 4, 6 and 9 are schematic, not patient data.