Comparative Analysis of Serum Calcium and Phosphorus Levels: Cord Blood vs. Maternal Blood

Background: The fetal demand for calcium and phosphorus is nearly inexhaustible, with the placenta transporting these minerals from the mother to meet the growing needs of the fetus.
Objective: To compare the status of calcium and phosphorus in cord blood versus maternal blood and assess the impact on maternal metabolism in coping with increased demands.
Methodology: After obtaining verbal consent, blood samples (n=104) were collected from mothers and the umbilical cord at the time of delivery in the maternity ward of JPMC. Serum calcium was analyzed using the Boehringer kit method, and phosphorus was estimated via atomic absorption spectrophotometry (Hitachi Z-8000). Statistical analysis was performed using SPSS version 20.
Results: The mean age of pregnant mothers was 25.3 ± 6.182 years, while the mean age of controls (n=24) was 25 ± 2.1 years. Among neonates, 42.9% (n=21) were female, and 57.1% (n=28) were male, with a mean weight of 2.99 ± 0.63 kg. The mean cord serum calcium was 8.69 ± 0.28 mg/dl, while maternal serum calcium was significantly lower at 8.13 ± 0.40 mg/dl (p<0.01) compared to controls (10.52 ± 0.6 mg /dl). Cord serum phosphorus levels were significantly higher than maternal levels (p<0.0001). A statistically significant negative relationship was found between the weight of the baby and maternal calcium level (r = -0.352, p = 0.024), but not with cord calcium or maternal/cord phosphate levels.
Conclusion: Mothers with low serum calcium concentration had correspondingly lower cord blood calcium levels compared to controls, despite compensatory mechanisms. However, the mean concentration of phosphorus in cord blood was significantly higher compared to maternal blood and controls.

Calcium, phosphorus, maternal, newborn, cord