There is no difference between a round and an elongated sac except for the shape, which is normal. Round and elongated sacs are related to the exact location of the sac, the length of the pregnancy, the size of the uterine cavity, and whether the pregnant woman has adequate nutrition, but not to other factors such as the sex of the baby. Long gestational sacs have a significant length-to-width ratio, while round gestational sacs have a smaller difference in length-to-width values, and the shape of the gestational sac can change at any time, and the shape can be different when viewed from different angles. Generally speaking, the shape of the gestational sac does not require much in the process of embryonic development, as long as the appearance is regular, the development of the embryo is normal, there is a normal fetal heart and buds growing, basically can judge the embryo is normal. In the clinical observation of the gestational sac is to know whether the tension of the gestational sac, fetal heart and fetal buds are normal or not, so the patient should not care about the shape of the gestational sac, do regular obstetric examination and keep a good mood.