Maternal first-trimester dietary intake and childhood blood pressure: the Generation R Study.

Suboptimal maternal dietary intake during pregnancy might lead to fetal cardiovascular adaptations and higher blood pressure in the offspring. The aim of the present study was to investigate the associations of maternal first-trimester dietary intake with blood pressure in children at the age of 6 years. We assessed first-trimester maternal daily dietary intake by a FFQ and measured folate, homocysteine and vitamin B12 concentrations in the blood, in a population-based prospective cohort study among 2863 mothers and children. Childhood systolic and diastolic blood pressure was measured using a validated automatic sphygmomanometer. First-trimester maternal daily intake of energy, fat, protein and carbohydrate was not associated with childhood blood pressure. Furthermore, maternal intake of micronutrients was not associated with childhood blood pressure. Also, higher maternal vitamin B12 concentrations were associated with a higher diastolic blood pressure (0·31 mmHg per standard deviation increase in vitamin B12 (95% CI 0·06, 0·56)). After taking into account multiple testing, none of the associations was statistically significant. Maternal first-trimester folate and homocysteine concentrations were not associated with childhood blood pressure. The results from the present study suggest that maternal Fe intake and vitamin B12 concentrations during the first trimester of pregnancy might affect childhood blood pressure, although the effect estimates were small and were not significant after correction for multiple testing. Further studies are needed to replicate these findings, to elucidate the underlying mechanisms and to assess whether these differences in blood pressure persist in later life.

Polymorphisms in genes within the IGF-axis influence antenatal and postnatal growth.

Two pregnancy cohorts were used to investigate the association between single-nucleotide polymorphisms (SNPs) in genes within the insulin-like growth factor (IGF)-axis and antenatal and postnatal growth from birth to adolescence. Longitudinal analyses were conducted in the Raine pregnancy cohort (n = 1162) using repeated measures of fetal head circumference (HC), abdominal circumference (AC) and femur length (FL) from 18 to 38 weeks gestation and eight measures of postnatal height and weight (1-17 years). Replications of significant associations up to birth were undertaken in the Generation R Study (n = 2642). Of the SNPs within the IGF-axis genes, 40% (n = 58) were associated with measures of antenatal growth (P ⩽ 0.05). The majority of these SNPs were in receptors; IGF-1R (23%; n = 34) and IGF-2R (13%; n = 9). Fifteen SNPs were associated with antenatal growth (either AC or HC or FL) in Raine (P ⩽ 0.005): five of which remained significant after adjusting for multiple testing. Four of these replicated in Generation R. Associations were identified between 38% (n = 55) of the IGF-axis SNPs and postnatal height and weight; 21% in IGF-1R (n = 31) and 9% in IGF-2R (n = 13). Twenty-six SNPs were significantly associated with both antenatal and postnatal growth; 17 with discordant effects and nine with concordant effects. Genetic variants in the IGF-axis appear to play a significant role in antenatal and postnatal growth. Further replication and new analytic methods are required in order to better understand this key metabolic pathway integrating biologic knowledge about the interaction between IGF-axis components.