Currents move ocean water horizontally at the ocean's surface. Surface currents are driven mainly by the wind. Other forces such as the Coriolis effect and the location of landmasses do affect surface current patterns. The Coriolis Effect explains how the earth's spin causes the wind to curve.
The first blood test is done by taking a small amount of blood from your arm from 10 weeks to 13 weeks 6 days in pregnancy. Nuchal translucency ultrasound: The second step for Sequential Integrated Screening is a special ultrasound done from 11 weeks 2 days to 14 weeks 2 days of the pregnancy. This ultrasound measures the size of the nuchal translucency (NT) of the fetus.
You have the NT scan and blood draw in your first trimester, and then go back for an additional blood draw in your second trimester. They then calculate a unified result and present the results in the second trimester.