Table 1.
Comparison of demographic Indexes between SCH and unexposed controls in different groups.
| Characteristics# | Total | Preconception | T1 | T2 | T3 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SCH (n = 165) | CON (n = 2,923) | P | SCH (n = 56) | CON (n = 1,035) | P | SCH (n = 27) | CON (n = 663) | P | SCH (n = 51) | CON (n = 748) | P | SCH (n = 31) | CON (n = 477) | P | |
| Age(y), mean (SD) | 30.26 (3.56) | 30.36 (3.82) | 0.74 | 30.52 (3.89) | 30.23 (3.89) | 0.59 | 29.22 (3.31) | 30.18 (3.89) | 0.20 | 30.22 (3.30) | 30.60 (3.78) | 0.48 | 30.77 (3.56) | 30.50 (3.64) | 0.68 |
| Gestational age (d), mean (SD) | 274.78 (9.75) | 275.09 (9.66) | 0.68 | 273.68 (9.84) | 274.67 (9.90) | 0.46 | 275.52 (9.06) | 274.19 (10.61) | 0.52 | 274.33 (11.04) | 275.84 (8.82) | 0.25 | 276.84 (7.78) | 276.08 (8.83) | 0.64 |
| Race | |||||||||||||||
| Han | 159 | 2,880 | 0.03 | 52 | 1,014 | 0.04 | 27 | 654 | – | 50 | 741 | 0.48 | 30 | 471 | 0.36 |
| Other | 6 | 43 | 4 | 21 | 0 | 9 | 1 | 7 | 1 | 6 | |||||
| Gravidity | |||||||||||||||
| First | 92 | 1,556 | 0.13 | 38 | 576 | 0.14 | 12 | 354 | 0.001 | 26 | 396 | 0.93 | 16 | 230 | 0.29 |
| Second | 36 | 831 | 13 | 281 | 4 | 209 | 14 | 207 | 5 | 134 | |||||
| Third/higher | 37 | 536 | 5 | 178 | 11 | 100 | 11 | 145 | 10 | 113 | |||||
| Parity | |||||||||||||||
| First | 127 | 2,302 | 0.64 | 48 | 823 | 0.03 | 19 | 528 | – | 36 | 590 | – | 24 | 361 | – |
| Second | 36 | 602 | 6 | 204 | 8 | 130 | 15 | 156 | 7 | 112 | |||||
| Third/higher | 2 | 19 | 2 | 8 | 0 | 5 | 0 | 2 | 0 | 4 | |||||
| Delivery model* | |||||||||||||||
| Natural | 105 | 1,878 | 0.62 | 31 | 672 | 0.34 | 15 | 442 | 0.39 | 36 | 464 | 0.56 | 23 | 300 | 0.20 |
| C-section | 56 | 1,001 | 24 | 346 | 11 | 211 | 14 | 273 | 7 | 171 | |||||
| Forceps | 4 | 43 | 1 | 17 | 1 | 10 | 1 | 11 | 1 | 5 | |||||
*
One of the women who tested thyroid function in the third trimester of pregnancy used the method of buttock-assisted delivery. #T1, first trimester; T2, second trimester; T3, third trimester.