Anaemia

1) Iron deficiency is more common in multiparous women
2) Serum B12 levels fall in pregnancy and are lower in smokers while B12 binding capacity is increased in pregnancy. 

Deficiency is associated with megaloblastic anaemia as is folate deficiency
3) Hypersegmentation of neutrophil polymorphs is characteristic of folate deficiency but is also observed in pure iron deficiency anaemia
4) MCV is reduced in haemoglobinopathies such as thalassaemia and sickle cell disease