Generally speaking, the yolk sac can appear around 5-6 weeks of pregnancy. If the yolk sac is not seen on the 41st day of pregnancy, the situation is very normal, because the yolk sac has its own development process. For example, if a woman’s menstrual cycle is late, the appearance of the yolk sac will be delayed accordingly, but if the yolk sac is not seen for a long time, it should be taken seriously, because only if the size of the yolk sac is normal, it can only mean that the development of the fetus is normal, which will help to normalize the pregnancy. Yolk sac not found for a long time may also be ectopic pregnancy, need to go to the hospital in time for examination, under the guidance of the doctor to treat. In addition, during pregnancy, women should pay attention to eat more light food, but also to supplement the nutrition, such as eating more ribs and so on, eat more fresh vegetables and fruits to supplement vitamins, pay more attention to rest and do not overwork.