Table 1.
Baseline characteristics and ovarian reserve parameters of participants with different thyroid conditions.
| Variables | Normal thyroid function |
SCH/OH | Subclinical/overt hyperthyroidism |
P |
|---|---|---|---|---|
| N | 2540 | 290 | 37 | |
| Age (years) | 32.00 [29.00, 35.00] | 32.00 [29.00, 35.00] | 31.00 [29.00, 34.00] | 0.139 |
| BMI (kg/m2) | 20.81 [19.31, 22.66] | 21.36 [20.03, 24.03] | 21.08 [19.47, 23.24] | <0.001a |
| Duration of infertility (years) | 3.00 [2.00, 5.00] | 3.00 [2.00, 5.00] | 3.00 [2.00, 5.00] | 0.657 |
| Infertility type, n (%) | ||||
| Primary infertility | 1178 (46.4) | 156 (53.8) | 24 (64.9) | 0.006a |
| Secondary infertility | 1362 (53.6) | 134 (46.2) | 13 (35.1) | |
| TSH (µIU/mL) | 1.95 [1.42, 2.68] | 5.08 [4.54, 6.34] | 0.02 [0.00, 0.03] | <0.001a,b,c |
| FT4 (ng/dL) | 1.25 [1.14, 1.35] | 1.20 [1.10, 1.30] | 1.77 [1.44, 2.11] | <0.001a,b,c |
| FT3 (pg/mL) | 2.94 [2.73, 3.17] | 2.99 [2.75, 3.20] | 4.14 [3.21, 5.06] | <0.001b, c |
| TPOAb (IU/mL) | 6.35 [1.68, 12.27] | 9.33 [3.42, 42.90] | 32.90 [14.13, 143.10] | <0.001a,b,c |
| TgAb (IU/mL) | 12.55 [5.23, 23.27] | 14.69 [7.93, 187.00] | 108.30 [15.30, 696.80] | <0.001a,b,c |
| Positive TPOAb, n(%) | 261 (10.3) | 79 (27.2) | 18 (48.6) | <0.001a, b,c |
| Positive TgAb, n(%) | 327 (12.9) | 82 (28.3) | 18 (48.6) | <0.001a,b,c |
| Positive TAI, n(%) | 396 (15.6) | 95 (32.8) | 19 (51.4) | <0.001a,b,c |
| LH (IU/L) | 4.91 [3.76, 6.41] | 4.80 [3.59, 6.45] | 4.86 [3.90, 6.07] | 0.948 |
| E2 (pg/mL) | 34.90 [26.00, 47.50] | 32.60 [24.15, 45.65] | 41.10 [33.60, 58.80] | 0.004b,c |
| AMH (ng/mL) | 3.41 [1.94, 5.47] | 2.79 [1.46, 4.82] | 3.64 [1.54, 4.91] | 0.002a |
| AFC (n) | 10.00 [6.00, 14.00] | 9.00 [6.25, 14.00] | 9.00 [6.00, 14.00] | 0.849 |
| FSH (mIU/mL) | 6.78 [5.85, 8.01] | 7.03 [6.06, 8.09] | 6.72 [5.75, 7.69] | 0.237 |
| Prevalence of AMH< 1.2 ng/mL, n(%) | 308 (12.1) | 50 (17.2) | 5 (13.5) | 0.045a |
| Prevalence of AFC<5, n(%) | 329 (13.0) | 43 (14.8) | 3 (8.1) | 0.445 |
| Prevalence of DOR, n(%) | 166 (6.5) | 29 (10.0) | 1 (2.7) | 0.052 |
All data is presented as median [25th percentile, 75th percentile] or n (%).
Superscripts indicate significant differences between aNormal thyroid function and SCH/OH, b SCH/OH and subclinical/overt hyperthyroidism, and cNormal thyroid function and subclinical/overt hyperthyroidism.
Kruskal-Wallis rank-sum test is applied for comparisons among three groups of continuous variables, with pairwise comparisons via Dunn’s with Bonferroni correction. Categorical variables are compared using chi-squared test, with pairwise comparisons among multiple groups are conducted using the chi-square partitioning method.
SCH/OH, Subclinical/overt hypothyroidism; BMI, body–mass index; TSH, thyroid stimulating hormone; FT4, free thyroxine; FT3, free triiodothyronine; TPOAb, thyroid peroxidase antibody; TgAb, thyroglobulin antibody; TAI, thyroid autoimmunity; LH, luteinizing hormone; E2, estradiol; AMH, anti-müllerian hormone; AFC, antral follicle count; FSH, follicle stimulating hormone; DOR, diminished ovarian reserve.