What is the normal size of the gestational sac at 38 days of pregnancy? Pregnancy is an important experience in a woman\’s life, and changes in the size of the gestational sac are also one of the important indicators of fetal health. In early pregnancy, the size of the gestational sac is very important to observe and evaluate the embryo. What is the normal range of gestational sac size at 38 days of pregnancy? Below we will conduct a detailed analysis from the following aspects. 1. What are the methods for measuring the size of the gestational sac? The measurement of the size of the gestational sac is done through ultrasound examination. This technology is a common pregnancy examination.