Table 2.
Associations between covariates and depressive symptoms and 25(OH)D levels during pregnancy.
| Depressive symptoms | 25(OH)D levels | |||||
|---|---|---|---|---|---|---|
| Estimate in SD units | 95% CI | p | Estimate in SD units | 95% CI | p | |
| Age <40 vs. ≥40 years | −0.34 | −0.68, −0.01 | 0.05 | 0.11 | −0.72, 0.40 | 0.43 |
| Upper vs. lower secondary or lower | 0.07 | −0.13, 0.26 | 0.51 | 0.15 | −0.02, 0.32 | 0.08 |
| Smoking during pregnancy | ||||||
| No | Ref | — | — | Ref | — | — |
| Quit during the 1st trimester | 0.10 | −0.42, 0.62 | 0.70 | −0.31 | −0.75, 0.15 | 0.18 |
| Smoked throughout | 0.45 | −0.40, 1.31 | 0.30 | −0.62 | −1.30, 0.06 | 0.07 |
| Alcohol use during pregnancy vs. no | 0.32 | 0.04, 0.60 | 0.03 | 0.17 | −0.08, 0.41 | 0.18 |
| Body mass index in early pregnancy | ||||||
| <25 kg/m2 | Ref | — | — | Ref | — | — |
| 25–29.99 kg/m2 | 0.02 | −0.23, 0.28 | 0.86 | −0.37 | −0.57, −0.18 | 0.001 |
| ⩾30 kg/m2 | 0.25 | 0.02, 0.47 | 0.03 | −0.44 | −0.66, −0.22 | 0.001 |
| Any hypertensive disorder vs. no disorder | −0.10 | −0.31, 0.11 | 0.34 | −0.08 | −0.26, 0.10 | 0.38 |
| Any diabetes disorder vs. no disorder | −0.11 | −0.35, 0.13 | 0.35 | −0.09 | −0.30, 0.11 | 0.37 |
Associations measured with linear mixed-model regression analysis with depressive symptoms and 25(OH)D levels treated as time-varying within-person outcome and covariates treated as a time-varying within-person predictor. Gestational week at blood sampling was included as a time-varying within-person predictor. Estimates and 95% CIs reflect differences between categorical covariate variable groups in SD units. SD, standard deviation; CI, confidence interval, and 25(OH)D, 25-hydroxyvitamin D.