Comparison 5. DHA/mixed subgroups.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Preterm birth (< 37 weeks)	26	10304	Risk Ratio (M‐H, Fixed, 95% CI)	0.89 [0.81, 0.97]
1.1 DHA/largely DHA	12	4744	Risk Ratio (M‐H, Fixed, 95% CI)	0.84 [0.69, 1.02]
1.2 Mixed DHA/EPA	9	4172	Risk Ratio (M‐H, Fixed, 95% CI)	0.92 [0.83, 1.03]
1.3 Mixed DHA/EPA/other	5	1388	Risk Ratio (M‐H, Fixed, 95% CI)	0.71 [0.45, 1.11]
2 Early preterm birth (< 34 weeks)	9	5204	Risk Ratio (M‐H, Fixed, 95% CI)	0.58 [0.44, 0.77]
2.1 DHA/largely DHA	5	3260	Risk Ratio (M‐H, Fixed, 95% CI)	0.46 [0.28, 0.76]
2.2 Mixed DHA/EPA	2	860	Risk Ratio (M‐H, Fixed, 95% CI)	0.69 [0.49, 0.99]
2.3 Mixed DHA/EPA/other	2	1084	Risk Ratio (M‐H, Fixed, 95% CI)	0.41 [0.14, 1.25]
3 Prolonged gestation (> 42 weeks)	6	5141	Risk Ratio (M‐H, Fixed, 95% CI)	1.61 [1.11, 2.33]
3.1 DHA/largely DHA	3	2847	Risk Ratio (M‐H, Fixed, 95% CI)	2.12 [0.60, 7.49]
3.2 Mixed DHA/EPA	2	2106	Risk Ratio (M‐H, Fixed, 95% CI)	1.54 [1.04, 2.28]
3.3 Mixed DHA/EPA/other	1	188	Risk Ratio (M‐H, Fixed, 95% CI)	3.13 [0.13, 75.84]
4 Pre‐eclampsia (hypertension with proteinuria)	20	8306	Risk Ratio (M‐H, Fixed, 95% CI)	0.84 [0.69, 1.01]
4.1 DHA/largely DHA	6	3454	Risk Ratio (M‐H, Fixed, 95% CI)	0.98 [0.71, 1.33]
4.2 Mixed DHA/EPA	9	3506	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.69, 1.18]
4.3 Mixed DHA/EPA/other	5	1346	Risk Ratio (M‐H, Fixed, 95% CI)	0.40 [0.23, 0.71]
5 Caesarean section	28	8481	Risk Ratio (M‐H, Fixed, 95% CI)	0.97 [0.91, 1.03]
5.1 DHA/largely DHA	9	4327	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.87, 1.03]
5.2 Mixed DHA/EPA	10	2433	Risk Ratio (M‐H, Fixed, 95% CI)	1.10 [0.95, 1.27]
5.3 Mixed DHA/EPA/other	9	1721	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.75, 1.02]
6 Gestational length (days)	43	12517	Mean Difference (IV, Random, 95% CI)	1.67 [0.95, 2.39]
6.1 DHA/largely DHA	14	4791	Mean Difference (IV, Random, 95% CI)	2.44 [0.91, 3.98]
6.2 Mixed DHA/EPA	17	5760	Mean Difference (IV, Random, 95% CI)	1.23 [0.21, 2.24]
6.3 Mixed DHA/EPA/other	12	1966	Mean Difference (IV, Random, 95% CI)	1.42 [0.33, 2.50]
7 Perinatal death	10	7416	Risk Ratio (M‐H, Fixed, 95% CI)	0.75 [0.54, 1.03]
7.1 DHA/largely DHA	3	3475	Risk Ratio (M‐H, Fixed, 95% CI)	0.44 [0.21, 0.91]
7.2 Mixed DHA/EPA	6	3873	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.60, 1.27]
7.3 Mixed DHA/EPA/other	1	68	Risk Ratio (M‐H, Fixed, 95% CI)	0.67 [0.12, 3.74]
8 Stillbirth	16	7880	Risk Ratio (M‐H, Fixed, 95% CI)	0.94 [0.62, 1.42]
8.1 DHA/largely DHA	5	3639	Risk Ratio (M‐H, Fixed, 95% CI)	0.69 [0.28, 1.70]
8.2 Mixed DHA/EPA	8	3987	Risk Ratio (M‐H, Fixed, 95% CI)	1.06 [0.65, 1.73]
8.3 Mixed DHA/EPA/other	3	254	Risk Ratio (M‐H, Fixed, 95% CI)	0.70 [0.14, 3.51]
9 Neonatal death	9	7448	Risk Ratio (M‐H, Fixed, 95% CI)	0.61 [0.34, 1.11]
9.1 DHA/largely DHA	3	3673	Risk Ratio (M‐H, Fixed, 95% CI)	0.50 [0.20, 1.23]
9.2 Mixed DHA/EPA	6	3775	Risk Ratio (M‐H, Fixed, 95% CI)	0.73 [0.33, 1.62]
10 Low birthweight (< 2500 g)	15	8449	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.82, 0.99]
10.1 DHA/largely DHA	6	4118	Risk Ratio (M‐H, Fixed, 95% CI)	0.72 [0.56, 0.93]
10.2 Mixed DHA/EPA	6	3147	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.87, 1.07]
10.3 Mixed DHA/EPA/other	3	1184	Risk Ratio (M‐H, Fixed, 95% CI)	0.78 [0.51, 1.18]
11 Small‐for‐gestational age/IUGR	8	6907	Risk Ratio (M‐H, Fixed, 95% CI)	1.01 [0.90, 1.13]
11.1 DHA/largely DHA	2	3372	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.75, 1.20]
11.2 Mixed DHA/EPA	4	2506	Risk Ratio (M‐H, Fixed, 95% CI)	1.07 [0.93, 1.23]
11.3 Mixed EPA/DHA/other	2	1029	Risk Ratio (M‐H, Fixed, 95% CI)	0.78 [0.50, 1.22]
12 Birthweight (g)	43	11584	Mean Difference (IV, Random, 95% CI)	75.69 [37.84, 113.55]
12.1 DHA/largely DHA	17	6121	Mean Difference (IV, Random, 95% CI)	52.60 [26.96, 78.23]
12.2 Mixed DHA/EPA	15	4429	Mean Difference (IV, Random, 95% CI)	72.72 [6.67, 138.78]
12.3 Mixed DHA/EPA/other	11	1034	Mean Difference (IV, Random, 95% CI)	113.65 [12.54, 214.75]