Table 2.
Thyroid hormone concentrations in maternal plasma over the 3 trimesters of pregnancy (Timepoints 1 to 3) and three months postpartum (Timepoint 4).
| Timepoint 1 (n=167) | Timepoint 2 (n=487) | Timepoint 3 (n=465) | Timepoint 4 (n=479) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| GM (GSD) | Median (range) | GM (GSD) | Median (range) | GM (GSD) | Median (range) | GM (GSD) | Median (range) | ||
| TSH | All | 1.04 (2.65) | 1.18 (0.15, 3.21) | 1.36 (1.96) | 1.38 (0.57, 3.15) | 1.20 (1.76) | 1.28 (0.52, 2.45) | 0.90 (3.20) | 1.14 (0.07, 2.28) |
| (mIU/L) | High TPOAb | *2.03 (3.48) | *2.07 (0.48, 8.01) | *1.60 (2.92) | *2.01 (0.59, 4.58) | 1.13 (2.53) | 1.42 (0.20, 2.57) | 0.36 (8.42) | 0.53 (0.07, 2.28) |
| Normal TPOAb | 0.94 (2.41) | 1.10 (0.15, 2.52) | 1.32 (1.79) | 1.33 (0.57, 2.76) | 1.22 (1.63) | 1.27 (0.54, 2.38) | 1.11 (1.74) | 1.17 (0.50, 2.28) | |
| FT4 | All | 15.1 (1.18) | 14.9 (11.8, 19.6) | 14.1 (1.16) | 14.0 (11.6. 17.5) | 12.9 (1.24) | 12.6 (10.0, 16.6) | 14.3 (1.18) | 14.03 (11.6, 19.4) |
| (pmol/L) | High TPOAb | 14.6 (1.24) | 14.2 (8.9, 19.6) | 14.8 (1.18) | 14.4 (11.3, 19.6) | 13.7 (1.30) | 13.4 (10.6, 18.2) | *16.5 (1.51) | *15.8 (11.6, 28.2) |
| Normal TPOAb | 15.2 (1.17) | 15.1 (12.1, 18.7) | 14.0 (1.15) | 14.0 (11.6, 17.0) | 12.7 (1.23) | 12.5 (10.0, 15.9) | 14.0 (1.18) | 13.9 (11.7, 17.0) | |
| FT3 | All | 4.64 (1.16) | 4.62 (3.72, 5.58) | 4.54 (1.14) | 4.53 (3.69, 5.51) | 4.43 (1.23) | 4.36 (3.62, 5.41) | 4.16 (1.18) | 4.13 (3.30, 5.30) |
| (pmol/L) | High TPOAb | 4.38 (1.13) | 4.38 (3.46, 4.99) | 4.53 (1.18) | 4.55 (3.61, 5.47) | 4.41 (1.13) | 4.47 (3.79, 5.11) | 4.55 (3.26) | 4.49 (3.16, 7.77) |
| Normal TPOAb | 4.68 (1.16) | 4.69 (3.81, 5.58) | 4.54 (1.14) | 4.53 (3.70, 5.51) | 4.43 (1.25) | 4.35 (3.61, 5.42) | 4.10 (1.14) | 4.10 (3.30, 5.05) | |
| TPOAb a | n (%) | 8 (5 %) | 73 (15 %) | 70 (15 %) | 67 (14 %) | ||||
Note: Sample collection: Timepoint 1 (< 13 weeks), Timepoint 2 (14 – 26 weeks), Timepoint 3 (27 – 40 weeks), Timepoint 4 (3 months postpartum) GM, geometric mean; GSD, geometric standard deviation
Range defined as the 5th percentile (lower) and 95th percentile (upper) of the sample population.
*
p < 0.05, level of significance (high vs. normal TPOAb)
a
Threshold indicating participants with high TPOAb, n (%) > 9 IU/mL