| 5Objective: Normal pregnancy leads a combination of adaptive metabolic responses, the end result of which is to assure adequate delivery of mineral to fetus while affording protection to the maternal skeleton. Calcium homeostasis must adapt to the demands of pregnancy to supply the growing fetus with adequate calcium and phosphorous. Bone turnover increased during pregnancy to adapt the demands of fetus skeleton developing. If the bone chemical elements were deficiency might lead the loss of maternal bone mass and effect the development of the fetus skeleton. The purpose of this clinical investigation was to explore the changes of calcium and magnesium and biochemical markers of bone metabolism osteocalcin(BGP) and urinarycalcium (expressed as a ratio of urinary creatinine)in normal pregnancy, and to find out whether deficiency of theses bioelements correlates with bone-turnover.Methods: Sixty-three healthy women in the first pregnancy were selected randomly completed the study. All women had normal term deliveries and experienced no complication during pregnancy. None had a history ofthyroid disease, fracture or any disease known to affect bone metabolism. All of them had a normal dietary without special calcium and vitamin D supplement. They were divided into three groups, the early (16±l)w, the middle (26±l)w, the term (36±l)w according to the time of pregnancy. There were fourteen non-pregnancy health women as contrast. Biochemical study were performed to analyze a bone turnover during pregnancy. For the determinations of serum calcium(Ca), magnesium(Mg), phosphorous (P), osteocalcin(BGP), urine calcium, magnesium, phosphorous, deoxypyridnoline(DPD) and creatinine, venous blood and urine were taken from the subjects. Serum was immediately separated after blood collection and Ca P Mg were measured at once ,the rest serum was promptly frozen at -20 until the measurements of BGP were taken. Urinary Ca^ Mg -> P and Cr were also measured at once .The rest urine was frozen and kept at -20 until DPD was measured. All samples were assayed at one library . Statistical analyses of the above parameters were carried out using SPSS for Windows software packge. Result is presented as means±SEM.Results: Serum concentration of calcium decreased from 2.375±0.42mmol/L (non-pregnancy) to 1.710±0.31mmol/L (at term). There were significant different between pregnancy and non-pregnant groups(p<0.05), there were no significant difference in the pregnant groups respectively (p>0.05). Serum concentration of magnesium had a tendency to decrease, there were significant difference at early and term pregnant compared with control group (p<0.05,p<0.01). Serum phosphorous had a tendency to increase, but had no significant difference. Serum concentration of BGP decreased gradually from 7.24±4.04ng/ml to a nadir 3.93±2.56ng/ml in the term pregnancy (p<0.01) and there were significant difference among 3 pregnant groups. Urinary DPD/cr rose through pregnancy from 12.95±2.44 to 24.4±14.4(p<0.01) and had significant difference among 4 groups (p<0.01). Fasting urinary Ca/cr increased during pregnancy and significant difference between pregnancy and non-pregnancy (p<0.01),but there were no difference among three pregnancy groups. Fasting urinary Mg/cr ratio tended to rise through pregnancy to term. Urinary DPD/cr had a positive correlation with urinary Mg/cr and Ca/cr ,on the other hand , had a negative correlation with serum Ca.Conculsion: Changes in serum and urine makers of bone resorption and bone formation suggest that bone resorption increased greater than bone formation in pregnancy and the normal dietary could not supply adequate calcium, vitamin D even magnesium to maternal to meet the requirement of fetus developing. Deficiency of calcium and vitamin D is a commonly factor in bone massloss, deficiency of magnesium may be a cofactor. It may be essential that supply vitamin D and calcium as well as magnesium in normal pregnancy. Above biochemical markers should be determined regularly during pr...
|
PDF Full Text Request