Fetal Growth Restriction (FGR) is the Preferred Term
The term "fetal growth restriction" (FGR) is now preferred over "intrauterine growth restriction" (IUGR), as it more accurately reflects the pathophysiological process affecting the fetus specifically, rather than implying a broader intrauterine environment issue. 1
Rationale for Terminology Preference
The shift from IUGR to FGR represents an evolution in clinical understanding and precision:
Why FGR is More Accurate
Specificity: FGR explicitly identifies the fetus as the affected entity, emphasizing that this is a condition where the fetus fails to achieve its genetic growth potential due to pathological factors, most commonly placental dysfunction 1, 2
Pathophysiological Clarity: The term FGR better distinguishes between:
Clinical Focus: FGR directs attention to the fetus requiring surveillance and intervention, rather than suggesting a generalized intrauterine problem 4
Current Guideline Adoption
The most recent 2024 BJOG Green-Top Guideline No. 31 consistently uses "FGR" throughout its recommendations and definitions 1. Similarly, major international guidelines including:
- ACOG (2019) acknowledges both terms but increasingly uses FGR 5, 6
- FIGO (2021) primarily employs FGR terminology 2
- Recent German/Austrian/Swiss guidelines (2024-2025) use both terms interchangeably but favor FGR 7
Practical Implications
Both terms remain in clinical use, and you will encounter IUGR in older literature and some current practice settings 4, 8, 3. However, adopting FGR terminology:
- Improves communication by emphasizing the fetal-specific pathology
- Aligns with current international consensus definitions (Delphi consensus, Saving Babies Lives Care Bundle v3) 1
- Facilitates distinction from the broader category of small-for-gestational-age (SGA), where not all small fetuses are growth-restricted 1
In clinical documentation and communication, use FGR as the primary term while recognizing that IUGR remains acceptable and widely understood, particularly when communicating with providers trained in earlier eras or reviewing historical literature 6, 9.