Singers Alkali denaturation test
→ Fetal blood contains HbF & is resistant to acid & alkali whereas maternal blood contains HbA which is sensitive to acid & alkali.
→Procedure: Blood is collected in a tube & reagent (KOH or NaOH) is added to the tube
→ If the color is same then its Vasa Previa but if the color changes to brown than it is Placenta previa.
- Vasa previa will lead to increased fetal blood loss therefore can lead to fetal mortality.
- Vasa previa means it is fetal blood which is lost.
- Placenta previa means maternal blood is lost.
- Investigation in such cases should be done in antenatal period using doppler Usg.
- Management of such cases is cesarean section.