Polyunsaturated fatty acid levels at birth and child-to-adult growth: Results from the MEFAB cohort.

BACKGROUND: Prenatal exposure to polyunsaturated fatty acids (PUFAs) may influence childhood growth. However, available evidence mostly derived from short-term studies is inconsistent. OBJECTIVE: To assess whether fetal PUFA exposure is associated with height and body mass index (BMI), a common measure of adiposity, from 6 months to 23 years of age. METHODS: In the MEFAB cohort, we assessed cord blood phospholipid n-3 and n-6 PUFA levels, reflecting fetal exposure in late pregnancy. For 250 (45.2% females) participants, we collected a total of 1770 (n= 802 for females) repeated growth measurements from infancy to young adulthood. We examined sex-specific associations of PUFAs with height and BMI at different developmental ages (infant: 6 months; toddler: 2 years; pre-schooler: 4 years; school-aged child: 7 years; adolescent: 12 years; and young adult: 23 years) using fractional polynomial mixed models adjusted for important covariates. RESULTS: Higher n-3 PUFA levels were associated with higher infant length in males (ß= 0.44cm [95% CI: 0.07, 0.82] per SD increase), whereas, for females, higher n-6 PUFA concentrations were associated with lower length in infancy (ß= -0.69cm [95% CI: -1.08, -0.30] per SD increase). A higher ratio of n-3 to n-6 PUFAs was associated with higher infant length in both sexes (ß= 0.40cm [95% CI: 0.01, 0.78] and 0.42cm [95% CI: 0.05, 0.79] per unit increase for males and females, respectively). These associations were not detectable later in childhood and young adulthood. No associations with BMI were found at any time point examined. CONCLUSIONS: Our findings suggest a small sex-specific influence of PUFA status at birth on length in infancy, but this does not persist in later life up to young adulthood. PUFA status at birth does not seem to affect BMI from infancy till young adulthood.

Effect of maternal n-3 long-chain polyunsaturated fatty acid supplementation during pregnancy and/or lactation on adiposity in childhood: a systematic review and meta-analysis of randomized controlled trials.

It is hypothesized that prenatal and early postnatal exposure to n-3 long-chain polyunsaturated fatty acids (LCPUFAs) is negatively associated with adiposity later in life. We conducted a systematic review and meta-analysis to evaluate whether maternal n-3 LCPUFA supplementation in pregnancy and/or lactation exerts a beneficial effect on adiposity status in childhood. We searched six electronic databases till 20 May 2014 for randomized controlled trials (RCTs) of n-3 LCPUFA supplementation to pregnant and/or lactating women that reported data on body mass index (BMI), waist circumference, sum of skinfold thicknesses or body fat mass in children. Adiposity measures were grouped into three age categories: preschool children (<5 years), school-aged children (6-12 years), and adolescents (>13 years). Trial quality was assessed. We conducted fixed-effect and random-effects meta-analyses to combine study-specific estimates of differences between the supplemented and control groups. A total of 6 RCTs (9 publications) involving 2847 participants were included. Summary estimates showed no effect of maternal supplementation on BMI in preschool (standardized mean difference (SMD)=0.07, 95% confidence interval (CI)=-0.22, 0.36, P=0.65) and school-aged children (SMD=0.12, 95% CI=-0.06, 0.30, P=0.20). Because of sparse data, it was not possible to pool study results relating to other adiposity measures. There is currently no evidence to support that n-3 LCPUFA supplementation during pregnancy and/or lactation favourably affects child adiposity. Further high-quality trials are needed.