Placenta previa should be suspected in 3rd trimester in case of

Ans-A (Painless vaginal bleeding)Ref: William's Obstetrics, 23rd ed. chapter 35Placenta previa is used to describe a placenta that is implanted over or very near the internal cervical os.There are several possibilities: total placenta previa, marginal placenta previa, partial placenta previa.The most characteristic event in placenta previa is painless hemorrhage, which usually does not appear until near the end of the second trimester or after. However, bleeding may begin earlier, and some abortions may result from such an abnormal location of the developing placenta.Digital cervical examination is never permissible unless the woman is in an operating room with all the preparations for immediate cesarean delivery--even the gentlest digital examination can cause torrential haemorrhage.The simplest, safest, and most accurate method of placental localization is provided by transabdominal sonography. Accordingly, the average accuracy is 96 percent, and rates as high as 98 percent have been obtained. False-positive results are often a result of bladder distension. Therefore, scans in apparently positive cases should be repeated after emptying the bladder.Cesarean delivery is necessary in practically all women with placenta previa. Most often, a transverse uterine incision is possible. However, because foetal bleeding may result from a transverse incision into an anterior placenta, a vertical incision is sometimes employed. But, even when the incision extends through the placenta, maternal or fetal outcomes are rarely compromised.