28 weeks on USG-(TVS) a G2P1 female was detected as having major placenta pre. A confirm atoy scan should be performed:

If the earlier scan showed a placenta completely over the internal os it is most likely to persist in later scans.If the 18-20 weeks scan revealed a lowlying placenta or a marginal placenta prae placental localization is best repeated around 32 weeks(refer pgno:130 sheila textbook of obstetrics 2 nd edition)