There is no scientific basis for the claim that the gestational sac can reflect the development of the embryo. The gestational sac is the development of the fertilized egg, the specific form of individual differences, has nothing to do with gender, with the gradual development of the embryo, the gestational sac can gradually increase, so through the size of the gestational sac can determine the development of the embryo, such as the gestational sac is smaller than the same level of gestational weeks, suggesting that the embryo is not well developed or the gestational week is calculated incorrectly; such as the gestational sac is larger than the same level of gestational weeks, the gestational week should be calibrated again. Timely monitoring of the gestational sac can also help to detect abnormal embryonic development as early as possible, such as changes in the morphology of the gestational sac, irregular edges, fluid accumulation around the gestational sac, suggesting that the embryo is underdeveloped and at risk of miscarriage, and can be weighed against the advantages and disadvantages of termination of pregnancy in a timely manner. It is important to note that patients with abnormalities in the sac should seek medical treatment as soon as possible to avoid delaying the condition, leading to adverse consequences.