Circulating divalent cations in asymptomatic ovarian hyperstimulation and in vitro fertilization patients

It is known that ovarian hyperstimulation and in vitro fertilization are accompanied by a steady increase in circulating estrogen and progesterone far beyond what is normal for young women. We have recently demonstrated that the biologically active fractions of calcium and magnesium in blood are altered depending on when in the menstrual phase a blood sample is drawn in normal cycling women. The serum ionized Ca/Mg ratio is also altered in accordance with the menstrual cycles. This suggests that the sex steroid hormones may modulate serum levels of ionized Mg and the ionized Ca/Mg ratio. We therefore studied the relationships between sex steroid hormones and the concentrations of ionized magnesium and calcium in the blood of hyperstimulated patients. We were able to demonstrate that with each increment in estrogen, a decrease in ionized Mg occurred, and as the progesterone rose in the blood, the ionized Ca/Mg ratio increased. Our results support the idea that serum estrogen and progesterone levels in women modulate the blood levels of circulating ionized Mg and the serum ionized Ca/Mg ratio.