Table 2. Comparison of serum calcium, phosphorus and PTH in the normal pregnant group, the PL group, the non-gravid group 1 and the non-gravid group 2.

Variables	Normal pregnancy	PL	Non-gravid 1	Non-gravid 2
Calcium (mmol/l) (mean±s.d.)	1.69±0.17a	1.56±0.17b	1.65±0.16	1.59±0.20
Phosphorus (mmol /l) (mean±s.d.)	1.04±0.22	1.02±0.15	1.01±0.12	0.99±0.10
PTH (pg/ml) (mean±s.d.)	290.54±157.60c	227.36±86.78c	164.69±66.13	480.96±252.88d

Abbreviations: PL, pregnancy loss; PTH, parathyroid hormone.

^aSignificantly higher compared with the PL group and the non-gravid group 2 (P=0.005 and 0.043, respectively).

^bSignificantly lower compared with the non-gravid group 1 (P=0.034).

^cSignificantly higher compared with the non-gravid group 1 (P=0.001 and 0.016, respectively).

^dSignificantly higher compared with the normal pregnant group, the PL group and the non-gravid group 1 (P=0.006, 0.000 and 0.000, respectively).