Does Pregnancy actually affect serum calcium and inorganic phosphate levels?

The serum level of calcium and inorganic phosphate in pregnancy is less well defined among Black – Nigerians, than among Caucasians. This case – control study assessed the relation of serum calcium and inorganic phosphate concentrations to pregnancy in Nigerian women. Blood samples were collected by venepuncture technique from 128 pregnant women during their first, second and third trimesters. A total of 72 non – pregnant women were recruited as controls. Serum calcium and inorganic phosphate levels were determined.Pregnant women had significantly lower serum levels of calcium and inorganic phosphate compared to controls (P<0.000 and P<0.001) respectively. There was a statistically significant progressive decrease in serum calcium and inorganic phosphate concentration from first trimester to third trimester (P<0.000 and P<0.001) respectively. Serum calcium and inorganic phosphate may be reduced during pregnancy due to inadequate dietary intake. The decrease in serum calcium and inorganic phosphate levels parallels increase in gestational age. This may result from mineral transfer from mother to developing fetus.