The overall number of cases of STIs is:

Choice A: Decreased production of erythrocytes

This is not the primary cause of iron deficiency anemia during pregnancy. While erythrocyte production may be affected in certain conditions, it is not directly linked to iron deficiency anemia in pregnancy¹.

Choice B: Inadequate intake of iron

This is the correct answer. During pregnancy, the body needs more iron to make hemoglobin for the increased volume of blood. If the intake of iron is not sufficient, it could lead to iron deficiency anemia¹.

Choice C: Dilution of hemoglobin concentration

While it's true that the blood volume increases during pregnancy, leading to a relative dilution of hemoglobin, this is not the primary cause of iron deficiency anemia. The main issue is the lack of sufficient iron intake¹.

Choice D: The fetus establishing iron stores

While the fetus does require iron, which it gets from the mother, this is not the primary cause of iron deficiency anemia during pregnancy. The main issue is still the mother's inadequate intake of iron¹.

Choice A reason: CD4 counts are not used to detect HIV, but to monitor the progression of the infection and the immune system status. CD4 cells are a type of white blood cell that HIV targets and destroys. A normal CD4 count ranges from 500 to 1,500 cells per microliter of blood. A low CD4 count indicates a high risk of opportunistic infections and AIDS.

Choice B reason: Virus is a vague term that does not specify what kind of virus is being detected. HIV is a type of virus that belongs to the retrovirus family. It is difficult to detect the virus itself, as it hides inside the host cells and has a low concentration in the blood. Therefore, most laboratory tests focus on the antibodies that the body produces in response to the virus.

Choice C reason: HIV antibodies are the most common way to detect HIV, as they are produced by the immune system to fight the virus. Antibodies are proteins that bind to specific antigens (foreign substances) and mark them for destruction. HIV antibodies can be detected by a blood test, a saliva test, or a rapid test. However, antibodies may take several weeks to develop after exposure, so a negative test does not rule out the possibility of infection.

Choice D reason: CD8 counts are not used to detect HIV, but to monitor the immune system response and the viral load. CD8 cells are a type of white blood cell that kill infected cells and secrete antiviral substances. A high CD8 count indicates a strong immune response and a low viral load. A low CD8 count indicates a weak immune response and a high viral load.