Robson Ten-Group Classification (cesarean audit)
Robson Ten-Group Classification System: sorts a delivery into one of ten mutually-exclusive cesarean-audit groups by parity, previous cesarean, onset, presentation, plurality, and gestation.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Parity
- Nulliparous (no previous birth)
- Previous cesarean
- No
- Number of fetuses
- Single
- Presentation
- Cephalic (head-down)
- Gestational age
- Term (≥ 37 weeks)
- Onset of labor
- Induced labor
Result: Robson Group 2a — Nulliparous, single cephalic, term, induced labor.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Groups 1–5
- WHO-endorsed cesarean audit. Groups 1–4 are single cephalic term, no previous cesarean (split by parity then onset; 2a/2b and 4a/4b split induced vs pre-labor cesarean); 5 adds a previous cesarean.
- Groups 6–10
- 6 nulliparous breech, 7 multiparous breech, 8 multiple pregnancy, 9 transverse/oblique lie, 10 preterm single cephalic. An audit classification, not an individual risk.
What you enter
- Parity
- Previous cesarean
- Number of fetuses
- Presentation
- Gestational age
- Onset of labor (needed only for groups 1–4)
How this is calculated
Robson MS. Classification of caesarean sections. Fetal Matern Med Rev. 2001;12(1):23-39. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.