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. 2017 Jan 19;17:41. doi: 10.1186/s12884-017-1225-8

Table 6.

Associations between total seafood intake and the subcategories late preterm delivery (35 to <37 w), moderately preterm delivery (32 to <34 w) and early preterm delivery (22 to <32 w). N = 67,007 mothers in the Norwegian Mother and Child Cohort Study (MoBa) 2002–2008

All PTD Unadjusted Adjusted
n (%) HRa (95% CI) HRb (95% CI)
Late PTD (35 to <37 w) 2659 (4.0)
Total seafood intake
  ≤ 5 g/d (never/rarely) 2903 157 (5.4) 1 1
  > 5–20 g/d (<1 serving/week) 12,111 525 (4.3) 0.80 (0.67, 0.95) 0.82 (0.68, 0.98)
  > 20–40 g/d (1–2 servings/week) 26,684 1079 (4.0) 0.74 (0.63, 0.88) 0.78 (0.66, 0.92)
  > 40–60 g/d (2–3 servings/week) 16,194 586 (3.6) 0.66 (0.55, 0.79) 0.69 (0.58, 0.83)
  > 60 g/d (≥3 servings/week) 8144 312 (3.8) 0.70 (0.58, 0.85) 0.71 (0.58, 0.86)
P for trendc <0.001 <0.001
LCn-3PUFA from supplements
 No supplement 21,676 851 (3.9) 1 1
  < 0.30 g/d (median 0.16 g/d) 22,203 917 (4.1) 1.05 (0.96, 1.16) 1.07 (0.97, 1.18)
  ≥ 0.30 g/d (median 0.80 g/d) 22,157 891 (4.0) 1.03 (0.93, 1.13) 1.04 (0.94, 1.15)
P for trendc 0.609 0.450
Moderately PTD (32 to <34w) 491 (0.7)
Total seafood intake
  ≤ 5 g/d (never/rarely) 2778 32 (1.2) 1 1
  > 5–20 g/d (<1 serving/week) 11,680 94 (0.8) 0.70 (0.47, 1.04) 0.75 (0.50, 1.12)
  > 20–40 g/d (1–2 servings/week) 25,784 179 (0.7) 0.60 (0.41, 0.88) 0.68 (0.47, 0.99)
  > 40–60 g/d (2–3 servings/week) 15,730 122 (0.8) 0.67 (0.46, 0.99) 0.77 (0.52, 1.15)
  > 60 g/d (≥3 servings/week) 7896 64 (0.8) 0.70 (0.46, 1.07) 0.78 (0.51, 1.20)
P for trendc 0.432 0.792
LCn-3PUFA from supplements
 No supplement 20,987 169 (0.8) 1 1
  < 0.30 g/d (median 0.16 g/d) 21,424 138 (0.6) 0.83 (0.66, 1.05) 0.84 (0.66, 1.06)
  ≥ 0.30 g/d (median 0.80 g/d) 21,457 191 (0.9) 1.15 (0.94, 1.42) 1.19 (0.95, 1.48)
P for trendc 0.158 0.093
Early PTD (22 to <32 w) 480 (0.7)
Total seafood intake
  ≤ 5 g/d (never/rarely) 2777 31 (1.1) 1 1
  > 5–20 g/d (<1 serving/week) 11,680 94 (0.8) 0.72 (0.48, 1.08) 0.77 (0.51, 1.16)
  > 20–40 g/d (1–2 servings/week) 25,787 182 (0.7) 0.63 (0.43, 0.92) 0.71 (0.48, 1.04)
  > 40–60 g/d (2–3 servings/week) 15,724 116 (0.7) 0.66 (0.44, 0.98) 0.75 (0.50, 1.12)
  > 60 g/d (≥3 servings/week) 7899 57 (0.7) 0.65 (0.42, 0.99) 0.68 (0.43, 1.06)
P for trendc 0.116 0.196
LCn-3PUFA from supplements
 No supplement 21,005 180 (0.9) 1 1
  < 0.30 g/d (median 0.16 g/d) 21,438 152 (0.7) 0.83 (0.67, 1.03) 0.84 (0.67, 1.05)
  ≥ 0.30 g/d (median 0.80 g/d) 21,414 148 (0.7) 0.81 (0.65, 1.00) 0.81 (0.65, 1.01)
P for trendc 0.049 0.072

aHR: Hazard Ratio (Cox regression)

bAdjusted for maternal age, pre-pregnancy BMI, height, parity, energy intake, maternal education, smoking, marital status, household income, previous preterm delivery and LCn-3PUFA from supplements

c P for linear trend obtained by incorporating variable as linear term