| First author | Year of publica-tion | Nation | Number of cases/n | Age/year | Intervention | Primary outcome index |
|---|
| Exp | Con | Exp | Con | Exp | Con |
|---|
| GAO[8] | 2021 | China | 46 | 34 | 25.3±3.4 | 24.8±3.1 | Guidance on routine maternal care was given. The initial dose of L-T4 was 50 μg/d. TSH level was re-examined 2 weeks later and the dose was adjusted | Guidance on routine maternal care was given. The iodized salt was increased and the fat was reduced in the diet | GH, PH, GDM, PD | | YE[9] | 2016 | China | 28 | 28 | 22-34 | 22-34 | The fat was reduced, and the iodized salt and the protein were increased in the diet. Routine medication and nursing interventions were given. TSH was checked every 4‒6 weeks and the L-T4 dose was adjusted | The fat was reduced, and the iodized salt and the protein were increased in the diet. Routine medication and nursing interventions were given | GDM, GH, DM, LBW, FD, NA | | MA[10] | 2020 | China | 42 | 42 | 28.74±4.08 | 28.25±4.15 | The fat was reduced, and the iodized salt and the protein were increased in the diet. TSH level was checked once a month and the L-T4 dose was adjusted | The fat was reduced, and the iodized salt and the protein were increased in the diet. The dose of L-T4 was 50 μg/d | GH, GDM, FD, PD, NA, LBW, DM, abortion | | LIU[11] | 2021 | China | 49 | 49 | 26.9±4.6 | 26.8±4.7 | The fat was reduced, and the iodized salt and the protein were increased in the diet. TSH level was checked termly and the L-T4 dose was adjusted | The fat was reduced, and the iodized salt and the protein were increased in the diet. The dose of L-T4 was 25 μg/d | DM, FD, abortion, PD, NA, LBW | | CASEY[12] | 2017 | America | 339 | 338 | 27.7±5.7 | 27.3±5.7 | The initial dose of L-T4 was 100 μg/d. TSH level was checked once a month and the L-T4 dose was adjusted. TSH level was controlled in the range of 0.1‒2.5 mIU/L | A placebo of 100 μg was given daily with a dummy adjustment | GDM, GH, LBW, PD, FD | | BLUMENTHAL[13] | 2017 | Australia | 92 | 933 | 33.47±1.41 | 35.00±5.20 | The iodized salt was increased in the diet. The dose of L-T4 was 50 μg/d when TSH>2.5 mIU/L. TSH was checked every 4 weeks and the L-T4 dose was adjusted | The iodine was increased in diet and L-T4 was not given | DM, GH, GDM, PD, FD | | WANG[14] | 2012 | China | 28 | 168 | Not mentioned | 28.14±0.27 | The initial dose of L-T4 depended on the pregnant woman′s TSH level. TSH 2.5‒5 mIU/L: L-T4 50 μg/d; TSH >5‒8 mIU/L: L-T4 75 μg/d; TSH>8 mIU/L: L-T4 100 μg/d. TSH level was checked every 4 weeks and the L-T4 dose was adjusted | L-T4 was not given | GH, PD, LBW, PH, abortion, NA | | JU[15] | 2016 | China | 184 | 273 | 29.31±3.36 | 28.88±3.53 | The initial LT-4 dose was determined based on TSH level. Dose of LT-4 was adjusted according to the treatment objective of TSH | L-T4 was not given | GDM, GH, PH, PD, LBW |
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