[Thyroid hormone changes in women with pre-eclampsia and its relationship with the presence of pre-eclampsia].

OBJECTIVE:To study thyroid hormone changes in women with pre-eclampsia patients, the characteristics of thyroid disease and its relationship with pre-eclampsia. METHODS:From May 2011 to December 2012 171 patients with pre-eclampsia who delivered in Shengjing Hospital of China Medical University were recruited as pre-eclampsia(PE) group, among which 114 cases were defined as early onset pre-eclampsia (EP) group and 57 cases were defined as late onset pre-eclampsia (LP) group. And 171 healthy women with same age and same stage of pregnancy were selected as the control group. Their blood pressures were normal and they had no obstetrical complications. Serum thyrotropin (TSH), free triiodothyronine (FT3) and free thyroxine(FT4) levels were determined by solid-phase chemiluminescent enzyme immunoassay method (CMIA). Thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) were measured by electro-chemiluminescent assay (ECLIA). The positive rate was calculated (TPOAb > 5.6 U/L, TGAb > 4.1 U/L were defined as positive result). The relationship between TSH, FT3, FT4 level and blood pressure was analyzed in women with pre-eclampsia. RESULTS:(1) The median values of TSH, FT4 and FT3 in PE group were 3.4 mU/L, (12.0 ± 3.0) pmol/L and (3.9 ± 0.9) pmol/L. In the control group, they were 1.9 mU/L, (13.4 ± 2.4) and (5.0 ± 1.3) pmol/L. There were statistically significant differences between the two groups(P < 0.01). In EP group, the median values of TSH, FT4 and FT3 were 3.3 mU/L, (12.1 ± 3.4) pmol/L and (3.8 ± 0.9) pmol/L. The differences between EP group and the control group were statistically significant (P < 0.01). In LP group, the median values of TSH, FT4 and FT3 were 3.4 mU/L, (11.9 ± 3.1) pmol/L and (3.9 ± 1.0)pmol/L. There were statistically significant differences compared to the control group(P < 0.01). While there was no difference between EP group and LP group (P > 0.05). (2) The positive rate of TPOAb and TGAb in PE group were 15.2% (26/171) and 21.6% (37/171), and were 12.3% (21/171) and 14.6% (25/171) in the control group. There was statistically significant difference in the TGAb positive rate (P < 0.01), but the difference in TPOAb positive rate was not statistically different (P > 0.05). The TPOAb positive rates in EP group and LP group were 12.3% (14/114) and 21.1% (12/57), respectively, with no statistically significant difference (P > 0.05). And the positive rates of TGAb in EP group and LP group were 21.9% (25/114) and 21.1% (12/57) , respectively, with no statistically significant difference (P > 0.05). The positive rate of TPOAb in LP group and in the control group had statistically significant difference (P < 0.01). (3) The morbidity of thyroid disease in PE group and in the control group were 47.4% (81/171) and 16.4% (28/171) , with statistically significant difference (P < 0.01). (4) The morbidity of subclinical hypothyroidism or hypothyroidism in PE group and in the control group were 45.0% (77/171) and 16.4% (28/171) , with statistically significant difference(P < 0.01). (5) The morbidity of subclinical hyperthyroidism in PE group and in the control group were 2.3% (4/171) and 1.8% (3/171) , with no statistically significant difference (P > 0.05). (6) In PE group, women with TSH level of 0.3-3.3 mU/L had systolic pressure of (170 ± 21) mmHg (1mmHg = 0.133 kPa) and diastolic pressure of (112 ± 15) mmHg; women with TSH > 3.3 mU/L had systolic pressure of (166 ± 21) mmHg and diastolic pressure of (109 ± 13) mmHg. There was no statistically significant difference (P > 0.05). But the diastolic pressure in EP group and LP group had statistically significant difference (P < 0.01). In PE group, no correlation was found among TSH, FT4 levels and systolic pressure, diastolic pressure (P > 0.05). FT3 level was negatively correlated to diastolic pressure (r = -0.172, P = 0.023) . CONCLUSIONS:It is common that pre-eclampsia is complicated with thyroid dysfunction, mainly subclinical hypothyroidism. Thus it is nessesary to test thyroid hormone and thyroid antibodies in women with pre-eclampsia. The decrease of FT3 and FT4, the increase of TSH and the presence of TPOAb and TGAb are related with the presence of pre-eclampsia.