Table 4.
Comparison of pregnancy outcomes among euthyroid, transient IMH, and persistent IMH groups using trend Chi-square test and multivariate logistic regression
| Outcome | Incidence (%) | P-value for trend a | Transient vs. Euthyroid | Persistent vs. Transient | Persistent vs. Euthyroid | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Euthyroid (N = 31,349) |
Transient IMH (N = 1,347) |
Persistent IMH (N = 510) |
OR (95% CI) | p-value b | OR (95% CI) | p-value c | OR (95% CI) | p-valueb | ||
| GDM | 9.9 | 18.3 | 16.3 | < 0.001 * | 1.41 (1.20–1.66) | < 0.001 * | 0.86 (0.64–1.16) | 0.325 | 1.24 (0.96–1.60) | 0.093 |
| Preeclampsia | 1.8 | 2.4 | 5.7 | < 0.001 * | 1.11 (0.75–1.65) | 0.603 | 2.33 (1.34–4.05) | 0.003 * | 2.52 (1.67–3.80) | < 0.001 * |
| Preterm birth | 4.0 | 4.8 | 6.7 | 0.001 * | 1.09 (0.82–1.45) | 0.541 | 1.46 (0.93–2.30) | 0.102 | 1.54 (1.07–2.23) | 0.021 * |
| Macrosomia | 5.9 | 9.9 | 11.6 | < 0.001 * | 1.52 (1.24–1.87) | < 0.001 * | 1.15 (0.82–1.62) | 0.418 | 1.77 (1.33–2.37) | < 0.001 * |
| Emergency CS | 6.1 | 7.4 | 10.2 | < 0.001 * | 1.02 (0.82–1.28) | 0.865 | 1.26 (0.87–1.82) | 0.227 | 1.29 (0.95–1.75) | 0.103 |
| Fetal distress | 4.3 | 7.9 | 10.4 | < 0.001 * | 1.42 (1.15–1.76) | 0.001 * | 1.20 (0.84–1.71) | 0.320 | 1.72 (1.28–2.32) | < 0.001 * |
| LBW | 1.9 | 1.8 | 3.1 | 0.167 | 0.91 (0.58–1.44) | 0.686 | 1.91 (0.96–3.39) | 0.064 | 1.63 (0.96–2.76) | 0.071 |
Abbreviations GDM Gestational Diabetes Mellitus, IMH isolated maternal hypothyroxinemia, CS cesarean section, LBW low birth weight, OR Odds Ratio, CI Confidence Interval
a P-value for trend across categories of different groups
b P values from multivariable logistic regression (reference: euthyroid group), adjusted for maternal age, pre-pregnancy BMI, gravidity, parity, and educational level
c The p-values taken from multivariable logistic regression comparing the persistent IMH group with the transient IMH group
* P < 0.05 was considered statistically significant