Can you tell the difference on an ultrasound scan a 6 week pregnancy to 10 pregnancy?

Yes, there are several key differences between an ultrasound scan of a 6-week pregnancy and a 10-week pregnancy. Here are a few of the notable changes:

Gestational sac:

- At 6 weeks, the gestational sac is usually about 2-3 millimeters in size and appears as a small, round, or oval structure.

- At 10 weeks, the gestational sac has grown significantly and may measure around 30-40 millimeters. It becomes more visible and takes on a more defined shape.

Embryonic development:

- At 6 weeks, the embryo is very small and may not be visible on an ultrasound. However, the yolk sac, which provides nourishment to the embryo, can be seen within the gestational sac.

- At 10 weeks, the embryo has developed significantly and is more easily visualized. The head is more prominent, and the beginnings of the arms and legs can be seen. The embryo may also start to exhibit some movement.

Fetal heart rate:

- At 6 weeks, the fetal heart rate may not be detectable or may be very slow, around 100 beats per minute (bpm).

- At 10 weeks, the fetal heart rate is typically stronger and more regular, ranging from 120 to 160 bpm.

Fetal pole length:

- At 6 weeks, the fetal pole length, which is the measurement from the crown of the head to the rump, is usually about 1-2 millimeters.

- At 10 weeks, the fetal pole length increases to approximately 20-30 millimeters. This measurement is used to estimate the gestational age of the pregnancy.

Other structures:

- At 6 weeks, other structures such as the placenta and umbilical cord may not be clearly visible.

- At 10 weeks, the placenta starts to develop and can be seen as a thickened area on the uterine wall. The umbilical cord, which connects the fetus to the placenta, also becomes more apparent.

It's important to remember that these are general observations and may vary depending on individual cases and the quality of the ultrasound scan. A qualified medical professional can provide a more accurate interpretation of an ultrasound and assess the progress of the pregnancy.