Calcitonin gene- and parathyroid hormone-related peptides in normotensive and preeclamptic pregnancies: a nested case–control study

Purpose To identify whether CGRP and PTHrP serve as screening biomarkers for early detection of preeclampsia or even before the development of preeclampsia in early pregnancy. Methods It was a nested case–control study. The subjects were divided into normotensive (controls) and preeclamptic (cases) groups. Serum samples of 132 cases and 132 controls were collected during pregnancy at three different gestational periods and one sample post delivery, from within the cohort of pregnant women reporting to antenatal clinic. Circulating levels of CGRP and PTHrP were analyzed by enzyme-linked immunosorbent assay. Results Maternal serum concentrations of CGRP and PTHrP increased with the advancement of gestation age in both normotensive and preeclamptic pregnancies but the significantly less increased levels were observed in preeclamptic pregnancies as compared with normotensive pregnancies. In postpartum period level of CGRP significantly falls in both groups although level of PTHrP continues to increase even after delivery. Maternal serum CGRP and PTHrP concentrations were positively correlated with the infant’s birth weights. Conclusion Maternal circulating CGRP and PTHrP concentrations were significantly lower in women with preeclampsia, which may contribute to the development of preeclampsia.