The accuracy of determining the size of the gestational sac for men and women. In families giving birth to children, wanting to know the gender of the fetus is a matter of great concern to every expectant parent. In addition to special examinations such as B-ultrasound, gestational sac size has also become a popular method for predicting fetal gender. This article will explore the accuracy of gestational sac size in predicting fetal gender from four aspects. Aspect 1: The relationship between the size of the gestational sac and the gender of the fetus The gestational sac is a cavity structure formed in the early stage of the embryo, which is filled with cyst fluid around the embryo. The size of the gestational sac can reflect the growth of the embryo during pregnancy. However, the size of the gestational sac cannot be directly related to the fetal