Not sure if anyone else has had this as all the googling only directs towards the early weeks not 2nd trimester in terms of yolk sac. I am 12 weeks now and thought the yolk sac should disappear by now when placenta takes over but I can still see the yolk sac (hard to miss due to size) on the scan. The sonographer wasnt worried and said the baby is measuring on track so I asked about the yolk sac size she said about 7mm. I am now really worried as it should not be more than 6mm? I know I should not be googling but there are lots stories about yolk sac indicating miscarriage when its bigger than 6mm. Has anyone else here had a yolk sac hanging around after 12 weeks and measuring large?