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.
There are three parts of first trimester screening: 1  Ultrasound test for fetal nuchal translucency (NT). Nuchal translucency screening uses an ultrasound test to examine the area at the back of the fetal neck for increased fluid or thickening. 2  Two maternal serum (blood) tests.