Summary of findings for the main comparison. Birth/infant outcomes.
| Omega‐3 LCPUFA compared with no omega‐3 during pregnancy: birth/infant outcomes | ||||||
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Population: pregnant women and their babies Settings: Angola (1 RCT), Australia (1 RCT), Belgium (1 RCT), Canada (1 RCT), Chile (1 RCT), Croatia (1 RCT), Chile (1 RCT), Denmark (3 RCTs), Egypt (1 RCT), Germany (2 RCTs), India (1 RCT), Iran (3 RCTs), Italy (1 RCT), Mexico (1 RCT), Netherlands (3 RCTs), Norway (1 RCT), Russia (1 RCT), Sweden (1 RCT), Turkey (1 RCT), UK (4 RCTs), USA (8 RCTs) Intervention: omega 3 Comparison: no omega‐3 | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Risk with no omega‐3 | Risk with omega‐3 | |||||
| Preterm birth < 37 weeks | 134/1000 | 119 per 1000 (109 to 130) |
RR 0.89 (0.81 to 0.97) | 10,304 (26 RCTs) | ⊕⊕⊕⊕ HIGH1 |
|
| Early preterm birth < 34 weeks | 46/1000 | 27 per 1000 (20 to 35) |
RR 0.58 (0.44 to 0.77) | 5204 (9 RCTs) | ⊕⊕⊕⊕ HIGH2 |
|
| Perinatal death | 20/1000 | 15 per 1000 (11 to 21) |
RR 0.75 (0.54 to 1.03) | 7416 (10 RCTs) | ⊕⊕⊕⊝ MODERATE3 |
|
| SGA/IUGR | 129/1000 | 130 per 1000 (116 to 146) |
RR 1.01 (0.90 to 1.13) | 6907 (8 RCTs) | ⊕⊕⊕⊝ MODERATE3 |
|
| LBW | 156/1000 | 140 (128 to 154) |
RR 0.90 (0.82 to 0.99) | 8449 (15 RCTs) | ⊕⊕⊕⊕ HIGH |
|
| LGA | 117/1000 | 134 per 1000 (113 to 159) |
RR 1.15 (0.97 to 1.36) | 3722 (6 RCTs) | ⊕⊕⊕⊝ MODERATE4 |
|
| Serious adverse events for neonate/infant | 63/1000 | 45 per 1000 (37 to 62) | RR 0.72 (0.53 to 0.99) | 2690 (2 RCTs) | ⊕⊕⊝⊝ low:5 |
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| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; LBW: low birth weight LGA: large‐for‐gestational age;RCT: randomised controlled trial; RR: risk ratio; SGA/IUGR: small‐for‐gestational age/intrauterine growth restriction | ||||||
| GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: we are very uncertain about the estimate. | ||||||
1 Design limitations: larger studies of high quality, but some smaller studies with unclear risk of selective reporting and some smaller studies with unclear or high attrition bias at the time of birth (not downgraded for study limitations)
2 Design limitations: larger studies of higher quality, but several studies with unclear or high attrition bias at the time of birth, or baseline imbalances (not downgraded for study limitations)
3 Imprecision (‐1): downgraded one level due to crossing line of no effect and/or wide confidence intervals
4 Imprecision (‐1): downgraded one level due to wide confidence intervals
5 Design limitations (‐2): downgraded two levels; one study with unclear allocation concealment and attrition bias; specific adverse events not detailed in this study