What is the gestational sac aspect ratio? The gestational sac aspect ratio refers to the vertical and horizontal size ratio of the gestational sac in the uterus of a pregnant woman. Generally, the gestational sac is longer than wide to accommodate the growing fetus. If the length-to-width ratio of the gestational sac is abnormal, it may indicate certain abnormalities, such as intrauterine pregnancy, intrauterine fetal arrest, or fetal malformation. How to determine the gender of the fetus? Based on the length-to-width ratio of the gestational sac, the size of the fetus