Good morning doctor,my wife got pregnent.delivery...

 When Does the Gestational Sac Become Visible on an Ultrasound?

• The gestational sac is usually the first sign of pregnancy on ultrasound and may be seen as early as 3 weeks. At this time the average diameter of the sac is 2 to 3 millimeters.

• At around 5.5 weeks the yolk sac often becomes visible inside the gestational sac.
• In viable pregnancies, a transvaginal ultrasound should be able to detect the gestational sac by 5 weeks gestational age.
• When correlated with hCG levels, a gestational sac should be seen on ultrasound when the hCG level when it has reached about 1500 to 2000.

How accurate are pregnancy tests?

• Pregnancy tests are most accurate when you take them after you’ve already missed your period.

• A pregnancy test will be less accurate if it’s expired or if you don’t use it the right way.
• So always check the expiration date on the package, and carefully read the directions that come with your pregnancy test.
• If your periods are very irregular, or you don’t get periods at all for one reason or another, your best bet for accurate results is to take a pregnancy test 3 weeks after sex

What if a gestational sac is not seen?

It could be

• Your dates are off. This is a common reason and may simply mean that you need a repeat ultrasound later on.

• It can be helpful to compare this finding with your hCG levels, which would likely be lower than 1500 if you are not as far along as you thought in your pregnancy.
• You have miscarried.
•     You have an ectopic pregnancy.
• If your hCG levels are between 1500 and 2000 but a gestational sac is not seen, it could mean that you have an ectopic pregnancy.