Cross-sectional study of serum parathyroid hormone level in high-risk pregnancies as compared to nonpregnant control

OBJECTIVES: To note the value of serum parathyroid hormone (PTH) levels in normal and high-risk pregnancies (HRP) in patients attending antenatal visits at All India Institute of Medical Sciences (AIIMS). MATERIALS AND METHODS: This is a cross-sectional study where a total of 282 patients attending Gynecology Outpatient Department at AIIMS, New Delhi were recruited. Among the 282 subjects, 251 were pregnant, and 31 were controls. The serum was tested for serum PTH levels using Beckman coulter access 2 immunoassay. RESULTS: The median value of PTH level in pregnant women was 31.6 pg/ml with range being 0.8–505.5 pg/ml in contrast to 45.9 pg/ml with range being 19–102.7 pg/ml in nonpregnant female. This difference was statistically significant (P = 0.0012). There was no significant difference in median level of PTH in different age group. Although the median PTH levels were lower in second trimester (25.25 pg/ml) than in first trimester (35.5 pg/ml) and in third trimester (32.4 pg/ml), the difference was not statistically significant. There was no significant difference in PTH level in HRP (median value – 31.6 pg/ml) as compared to low-risk pregnancies (31.5 pg/ml). CONCLUSION: Serum PTH levels are significantly lower during pregnancy as compared to nonpregnant state. However, age, parity, and HRP did not alter PTH level during pregnancy.