Table 2.
Mean birth weight, adjusted birth weight difference and OR with 95% CIs for preterm birth, SGA and LGA in singletons born to mothers with a first-time diagnosis of hyper–or hypothyroidism before, during or after pregnancy
| Nonea | Maternal diagnosis of hyperthyroidismb |
Maternal diagnosis of hypothyroidismb |
|||||
|---|---|---|---|---|---|---|---|
| before | during | after | before | during | after | ||
| Singletons, n | 1,605,529 | 4,381 | 1,262 | 15,980 | 1,887 | 1,241 | 8,058 |
| Birth weight (mean ± SD), g | 3,488 ± 559 | 3,448 ±588 | 3,426 ±600 | 3,425 ± 567 | 3,558 ± 607 | 3,529± 574 | 3,492 ±584 |
| Linear regression modelc | |||||||
| Birth weight difference, not including gestational age, g | |||||||
| Adjusted difference (95% CI) | ref. | –88 (–105 to–72) | –91 (–121 to–61) | –37 (–46 to–29) | 7 (–18 to 32) | 11 (–19 to 42) | 24 (12 to 36) |
| Birth weight difference, including gestational aged, g | |||||||
| Adjusted difference (95% CI) | ref. | –67 (–82 to–53) | –65 (–92 to–39) | –29 (–36 to–21) | 26 (4 to 48) | 30 (3 to 57) | 29 (19 to 40) |
| Logistic regression modelc | |||||||
| Preterm birth | |||||||
| Adjusted OR (95% CI) | ref. | 1.36 (1.20–1.54) | 1.43 (1.14–1.79) | 1.17 (1.09–1.25) | 1.26 (1.04–1.53) | 1.27 (1.01–1.60) | 1.13 (1.02–1.25) |
| Small-for-gestational-age | |||||||
| Adjusted OR (95% CI) | ref. | 1.27 (1.15–1.40) | 1.43 (1.20–1.69) | 1.11 (1.05–1.16) | 1.05 (0.88–1.24) | 1.02 (0.83–1.25) | 0.93 (0.86–1.00) |
| Large-for-gestational-age | |||||||
| Adjusted OR (95% CI) | ref. | 0.92 (0.83–1.01) | 0.94 (0.79–1.13) | 0.96 (0.91–1.02) | 1.15 (1.02–1.31) | 1.22 (1.04–1.43) | 1.27 (1.19–1.36) |
No maternal diagnosis of hyper-or hypothyroidism registered in the DNHR before January 1, 2007.
Maternal first time diagnosis of hyper-or hy-pothyroidism before, during or after pregnancy and registered in DNHR before January 1, 2007.
Model included the following variables obtained at the time of the child's birth: maternal age (<20, 20–24, 25–29, 30–34, 35–39, >40 years), calendar year (<1980, 1980–1982, 1983–1985, 1986–1988, 1989–1991, 1992–1994, 1995–1997, 1998–2000, 2001–2003, 2004–2006), parity including index pregnancy (1, 2, 3, ≥4), maternal cohabitation (married/not married), maternal income (1st, 2nd, 3rd, 4th quartile), maternal origin (born in Denmark/not born in Denmark), maternal residence (East/West Denmark) and maternal diagnosis of diabetes registered in DNHR before January 1, 2007 (yes/ no).
Gestational age at delivery (20–27, 28–32, 33–36, 37–41, 42–45 weeks).