Sickle cell disease occurs from genetic changes that cause abnormalities in hemoglobin molecules: 1  Hemoglobin A (HbA) . 2  HbA is the hemoglobin molecule found in normal red blood cells during childhood and adulthood. 3  People who do not have sickle cell disease generally have this type of hemoglobin in their blood cells.ickle cell disease is an inherited blood disorder in which the body produces abnormally shaped red blood cells. In sickle cell disease, the hemoglobin in red blood cells clumps together. This causes red blood cells to become stiff and C-shaped.
A few new pregnancy symptoms will be noticed with the rise and fall of hormonal levels when you are 2 months pregnant. Your waistline is increasing even though you have not put on any significant weight. There is a change in the texture of the hair and skin during pregnancy.
A normal pregnancy lasts for 40 weeks. A perfect normal full term pregnancy is 40 weeks. However, it is normal to go into labor at 37-38 weeks. How Many Weeks Is Pregnancy. A full term pregnancy is 40 weeks, but it is safe to delivery a baby between 38-42 without it having any health issue. 40. 40 weeks from the first day of your last period.  as said by brain child is correct. that is how the due date is calculated.