Table 2.
Association between maternal plasma total homocysteine (tHcy) and offspring birthweight and gestational age at birth
| Quintiles of tHcy (µmol/l) (median, range) | Birthweight (g) (mean, SD) | Gestation (weeks) (mean, SD) | |
|---|---|---|---|
| PMNS (N=526) | |||
| 1. 5.44 (1.78–6.34) | 2713 (348) | 39.4 (1.6) | |
| 2. 7.14 (6.38–7.78) | 2605 (402) | 38.9 (1.7) | |
| 3. 8.59 (7.79–9.37) | 2638 (392) | 39.1 (1.8) | |
| 4. 10.38 (9.38–11.38) | 2655 (389) | 39.1 (1.6) | |
| 5. 13.33 (11.41–27.59) | 2601 (357) | 39.1 (1.7) | |
| P1 | 0.02 | 0.15 | |
| β1 (95% CI) | –39 (–71, –7) | –0.10 (–0.25, 0.04) | |
| P2 | 0.11 | 0.16 | |
| β2 (95% CI) | –22 (–50, 5) | –0.10 (–0.25, 0.04) | |
| Parthenon (N=515) | |||
| 1. 4.49 (2.26–4.85) | 2921 (431) | 39.3 (1.6) | |
| 2. 5.31 (4.87–5.68) | 2928 (365) | 39.4 (1.3) | |
| 3. 6.03 (5.70–6.41) | 2909 (405) | 39.0 (1.6) | |
| 4. 6.82 (6.42–7.47) | 2821 (445) | 38.8 (1.7) | |
| 5. 8.51 (7.48–40.73) | 2772 (536) | 38.8 (2.2) | |
| P1 | <0.001 | 0.03 | |
| β1 (95% CI) | –74 (–112, –36) | –0.17 (–0.32, –0.02) | |
| P2 | 0.002 | 0.02 | |
| β2 (95% CI) | –57 (–92, –21) | –0.17 (–0.32, –0.02) | |
| Meta-analysis | |||
| P1 | <0.001 | 0.01 | |
| β1 (95% CI) | –56 (–81, –32) | –0.14 (–0.24, –0.03) | |
| P for heterogeneity | 0.16 | 0.5 | |
| I2 | 48.4% | 0.0% | |
| P2 | <0.001 | 0.009 | |
| β2 (95% CI) | –40 (–62, –17) | –0.14 (–0.24, –0.04) | |
| P for heterogeneity | 0.15 | 0.6 | |
| I2 | 51.0% | 0.0% | |
tHcy concentrations are shown as quintiles for ease of interpretation. However, in regression analysis tHcy is used as a continuous variable in SD units.
P1: unadjusted; P2: adjusted for gender and gestational age as appropriate.
β1, β2 represent corresponding effect sizes.