O21.0Mild hyperemesis gravidarum
Code usage status
Primary diagnosis
May be used as the primary diagnosis
Apply only when it matches the confirmed diagnosis and the documented clinical record.
Specificity
Complete code in the classification
Use when the diagnosis matches and no exclusion applies.
- Chapter XV
- Pregnancy, childbirth and the puerperium
- Official Vietnamese name
- Nôn nghén thể trung bình
- Additional WHO coding guidance
- Hyperemesis gravidarum, mild or unspecified, starting before the end of the 22nd week of gestation
Related O21 codes
O21
Excessive vomiting in pregnancy
O21.1
Primary diagnosis candidate
Hyperemesis gravidarum with metabolic disturbance
O21.2
Primary diagnosis candidate
Late vomiting of pregnancy
O21.8
Primary diagnosis candidate
Other vomiting complicating pregnancy
O21.9
Primary diagnosis candidate
Vomiting of pregnancy, unspecified
Clinical record checklist
View coding guide →- Confirm that the code matches the final documented diagnosis.
- Use one primary-diagnosis code and record only relevant additional conditions.
- Review Ministry indicators, inclusions, exclusions and notes.
- Do not infer a diagnosis beyond the clinical record.
2026 regulatory basis
Indicators are taken from columns 24–29 of the classification accompanying Circular 06/2026/TT-BYT, cross-referenced with Decision 1849/QĐ-BYT and Official Dispatch 4059/BYT-BH.
