What are the first visable signs of pregnancy using ultrasound?
Using transvaginal ultrasound, the first sign of pregnancy is the gestational sac within the uterus. We can see this, under optimal conditions, in the 4th week of pregnancy. A yolk sac is seen in the 5th week. A fetal pole cannot be seen until you have entered the 6th week. “The gestational sac is the earliest sonographic finding in pregnancy… The gestational sac first appears at about 4 weeks gestational age…While a gestational sac is sometimes seen as early as during the 4th week of gestation, it may not be seen until the end of the 5th week, when the serum HCG levels have risen to 1000-1500 mIU…
