Table 4 The subgroup analyses of studies regarding the association between maternal FA supplementation and the risk of ASD in offspring
Subgroup | No. of studies | OR (95%CI) | P-value | I2(%) |
|---|---|---|---|---|
Summary pooled estimate | 15 | 0.828 (0.716, 0.957) |  < 0.001 | 86.5 |
Design | ||||
 Case–control | 10 | 0.768 (0.646, 0.914) |  < 0.001 | 87.7 |
 Cohort or RCT | 5 | 1.010 (0.789, 1.291) | 0.004 | 74 |
Geographic region | ||||
 Europe or Australia | 7 | 0.892 (0.748, 1.065) |  < 0.001 | 83.4 |
 China | 4 | 0.564 (0.362, 0.879) |  < 0.001 | 90.8 |
 America | 4 | 1.008 (0.766, 1.327) | 0.002 | 79.5 |
Publication period | ||||
 Before 2010 | 1 | 1.200 (0.800, 1.800) |  |  |
 2010 or after | 14 | 0.811 (0.698, 0.941) |  < 0.001 | 87.1 |
Quality assessment | ||||
 High quality studies (scores ≥ 7) | 10 | 0.789 (0.652, 0.954) |  < 0.001 | 90.0 |
 Low quality studies (scores < 7) | 5 | 0.908 (0.730, 1.130) | 0.009 | 70.2 |
Confounding Factors | ||||
 Age | 13 | 0.795 (0.687, 0.919) |  < 0.001 | 86.8 |
 Maternal smoking | 4 | 0.748 (0.512, 1.094) |  < 0.001 | 91.8 |
 Maternal alcohol | 1 | 0.620 (0.469, 0.819) |  |  |
 Maternal BMI | 5 | 0.704 (0.508, 0.975) |  < 0.001 | 87 |
 Fetal sex | 1 | 0.780 (0.617, 0.986) |  |  |
 Family history | 2 | 0.664 (0.245, 1.801) |  < 0.001 | 94.6 |