Table 5 Associations between seafood intake and marine long chain n-3 polyunsaturated fatty acids (LCn-3PUFA) from supplements and the subcategories spontaneous and iatrogenic preterm delivery. N = 66,919^a women in the Norwegian Mother and Child Cohort Study (MoBa) 2002–2008

2051 (3.1)

1491 (2.2)

  ≤ 5 g/d (never/rarely)

2961

129 (4.4)

1

86 (2.9)

1

  > 5–20 g/d (<1 serving/week)

12,275

405 (3.3)

0.79 (0.64, 0.96)

284 (2.3)

0.81 (0.63, 1.03)

  > 20–40 g/d (1–2 servings/week)

27,010

802 (3.0)

0.73 (0.61, 0.89)

603 (2.2)

0.79 (0.63, 0.99)

  > 40–60 g/d (2–3 servings/week)

16,416

469 (2.9)

0.71 (0.58, 0.86)

339 (2.1)

0.74 (0.58, 0.94)

  > 60 g/d (≥3 servings/week)

8257

246 (3.0)

0.73 (0.58, 0.90)

179 (2.2)

0.71 (0.55, 0.92)

  P for trend^d

0.009

0.013

  ≤ 5 g/d (never/rarely)

7437

278 (3.7)

1

198 (2.7)

1

  > 5–20 g/d (<1 serving/week)

29,118

884 (3.0)

0.88 (0.77, 1.02)

653 (2.2)

0.89 (0.76, 1.05)

  > 20–40 g/d (1–2 servings/week)

24,806

723 (2.9)

0.88 (0.76, 1.02)

526 (2.1)

0.84 (0.71, 0.99)

  > 40–60 g/d (2–3 servings/week)

4797

139 (2.9)

0.85 (0.69, 1.04)

95 (2.0)

0.74 (0.57, 0.95)

  > 60 g/d (≥3 servings/week)

761

27 (3.5)

0.99 (0.67, 1.47)

19 (2.5)

0.81 (0.50, 1.31)

  P for trend^c

0.219

0.012

  ≤ 5 g/d (never/rarely)

22,003

746 (3.4)

1

527 (2.4)

1

  > 5–20 g/d (<1 serving/week)

33,257

949 (2.9)

0.89 (0.81, 0.99)

704 (2.1)

0.94 (0.84, 1.06)

  > 20–40 g/d (1–2 servings/week)

8640

256 (3.0)

0.91 (0.79, 1.06)

178 (2.1)

0.89 (0.75, 1.06)

  > 40–60 g/d (2–3 servings/week)

1897

59 (3.1)

0.94 (0.71, 1.23)

56 (3.0)

1.26 (0.95, 1.66)

  > 60 g/d (≥3 servings/week)

1122

41 (3.7)

1.10 (0.80, 1.51)

26 (2.3)

0.94 (0.63, 1.39)

  P for trend^c

0.411

0.804

 No supplement

21,999

671 (3.1)

1

503 (2.3)

1

  < 0.30 g/d (median 0.16 g/d)

22,456

671 (3.0)

0.97 (0.87, 1.09)

499 (2.2)

1.03 (0.90, 1.17)

  ≥ 0.30 g/d (median 0.80 g/d)

22,464

709 (3.2)

1.03 (0.92, 1.15)

489 (2.2)

1.01 (0.89, 1.15)

  P for trend^d

0.626

0.872