Question: what is iugs in pregnancy?
Answer: Gestational sac. Assoc Prof Frank Gaillard ◉ ◈ et al. The gestational sac (GS) is the first sign of early pregnancy on ultrasound and can be seen with endovaginal ultrasound at approximately 3-5 weeks gestation when the mean sac diameter (MSD) would approximately measure 2-3 mm in diameter.