Aisling A. Geraghty

Nutrition During Pregnancy Impacts Offspring's Epigenetic Status-Evidence from Human and Animal Studies.

Pregnancy is a vital time of growth and development during which maternal nutrition significantly influences the future health of both mother and baby. During pregnancy, the fetus experiences a critical period of plasticity. Epigenetics, specifically DNA methylation, plays an important role here. As nutrition is influential for DNA methylation, this review aims to determine if maternal nutrition during pregnancy can modify the offsprings epigenome at birth. Research focuses on micronutrients and methyl donors such as folate and B vitamins. Evidence suggests that maternal nutrition does not largely influence global methylation patterns, particularly in nutrient-replete populations; however, an important impact on gene-specific methylation is observed. A link is shown between maternal nutrition and the methylome of the offspring; however, there remains a paucity of research. With the potential to use DNA methylation patterns at birth to predict health of the child in later life, it is vital that further research be carried out.

Maternal Blood Lipid Profile during Pregnancy and Associations with Child Adiposity: Findings from the ROLO Study

Background The in-utero environment affects fetal development; it is vital to understand how maternal diet during pregnancy influences childhood body composition. While research indicates that triglycerides in hyperglycaemic women may increase birth weight, little is known about this relationship in euglycemic women. This study examines the relationship between maternal blood lipid status and infant adiposity up to 2 years of age. Methods Data from 331 mother-child pairs from the ROLO longitudinal birth cohort study was analysed. Maternal dietary intakes were recorded and fasting blood lipids, leptin and HOMA were measured in early and late pregnancy and cord blood. Infant anthropometric measurements and skin-fold thicknesses were recorded at birth, 6 months and 2 years. Correlation and regression analyses were used to explore associations between maternal blood lipid status and infant adiposity. Results All maternal blood lipids increased significantly during pregnancy. Maternal dietary fat intake was positively associated with total cholesterol levels in early pregnancy. Late pregnancy triglycerides were positively associated with birth weight (P = 0.03) while cord blood triglycerides were negatively associated with birth weight (P = 0.01). Cord HDL-C was negatively associated with infant weight at 6 months (P = 0.005). No other maternal blood lipids were associated with infant weight or adiposity up to 2 years of age. Conclusion Maternal and fetal triglycerides were associated with birth weight and cord HDL-C with weight at 6 months. Thus, maternal lipid concentrations may exert in-utero influences on infant body composition. There may be potential to modulate infant body composition through alteration of maternal diet during pregnancy.

A Low Glycaemic Index Diet in Pregnancy Induces DNA Methylation Variation in Blood of Newborns: Results from the ROLO Randomised Controlled Trial

The epigenetic profile of the developing fetus is sensitive to environmental influence. Maternal diet has been shown to influence DNA methylation patterns in offspring, but research in humans is limited. We investigated the impact of a low glycaemic index dietary intervention during pregnancy on offspring DNA methylation patterns using a genome-wide methylation approach. Sixty neonates were selected from the ROLO (Randomised cOntrol trial of LOw glycaemic index diet to prevent macrosomia) study: 30 neonates from the low glycaemic index intervention arm and 30 from the control, whose mothers received no specific dietary advice. DNA methylation was investigated in 771,484 CpG sites in free DNA from cord blood serum. Principal component analysis and linear regression were carried out comparing the intervention and control groups. Gene clustering and pathway analysis were also explored. Widespread variation was identified in the newborns exposed to the dietary intervention, accounting for 11% of the total level of DNA methylation variation within the dataset. No association was found with maternal early-pregnancy body mass index (BMI), infant sex, or birthweight. Pathway analysis identified common influences of the intervention on gene clusters plausibly linked to pathways targeted by the intervention, including cardiac and immune functioning. Analysis in 60 additional samples from the ROLO study failed to replicate the original findings. Using a modest-sized discovery sample, we identified preliminary evidence of differential methylation in progeny of mothers exposed to a dietary intervention during pregnancy.

Five Year Follow-Up of a Low GI Dietary Randomised Controlled Trial in Pregnancy - No Long-Term Maternal Effects of a Dietary Intervention

To determine whether a dietary intervention in pregnancy had a lasting effect on maternal outcomes of diet, HbA1c and weight retention 5 years post‐intervention; and to establish whether modifiable maternal behaviours were associated with these outcomes.

Lower education predicts poor response to dietary intervention in pregnancy, regardless of neighbourhood affluence: secondary analysis from the ROLO randomised control trial

OBJECTIVE To determine if response to a low glycaemic index (GI) dietary intervention, measured by changes in dietary intake and gestational weight gain, differed across women of varying socio-economic status (SES). DESIGN Secondary data analysis of the ROLO randomised control trial. The intervention consisted of a two-hour low-GI dietary education session in early pregnancy. Change in GI was measured using 3 d food diaries pre- and post-intervention. Gestational weight gain was categorised as per the 2009 Institute of Medicine guidelines. SES was measured using education and neighbourhood deprivation. SETTING The National Maternity Hospital, Dublin, Ireland. SUBJECTS Women (n 625) recruited to the ROLO randomised control trial. RESULTS The intervention significantly reduced GI and excess gestational weight gain (EGWG) among women with third level education residing in both disadvantaged (GI, mean (sd), intervention v. control: -3·30 (5·15) v. -0·32 (4·22), P=0·024; EGWG, n (%), intervention v. control: 7 (33·6) v. 22 (67·9); P=0·022) and advantaged areas (GI: -1·13 (3·88) v. 0·06 (3·75), P=0·020; EGWG: 41 (34·1) v. 58 (52·6); P=0·006). Neither GI nor gestational weight gain differed between the intervention and control group among women with less than third level education, regardless of neighbourhood deprivation. CONCLUSIONS A single dietary education session was not effective in reducing GI or gestational weight gain among less educated women. Multifaceted, appropriate and practical approaches are required in pregnancy interventions to improve pregnancy outcomes for less educated women.

Low education predicts poor response to dietary intervention in pregnancy, regardless of neighbourhood affluence – secondary analysis from the ROLO randomised control trial

This abstract was awarded the student prize for best poster original communication. Low socioeconomic status (SES) is associated with reduced diet quality, gestational weight gain (GWG) outside of Institute of Medicine (IOM) guidelines and poorer pregnancy outcomes. A paucity of data exists regarding the response of women of low SES to interventions in pregnancy. We aimed to determine if response to a low glycaemic index (GI) dietary intervention, measured by changes in diet and excess GWG, differed across women of high/low educational attainment and neighbourhood deprivation. This was secondary data analysis of 754 women recruited to the ROLO study (Randomised cOntrol trial of a LOw glycaemic index diet in pregnancy to prevent macrosomia) between 2007 and 2011. The intervention consisted of a 2-hour low GI education session with a dietitian. Change in GI and nutrient intakes were measured using 3-day food diaries preand post-intervention. Weight, height and BMI (kg/m) were measured at the first antenatal visit. GWG was recorded throughout pregnancy. Excess GWG was categorised as per the 2009 IOM guidelines. Neighbourhood deprivation indices were assigned using an Irish census data index, and categorised as advantaged or disadvantaged. Self-reported education was categorised as achieved or did not achieve 3 level education. The mean changes in nutrient intakes from pre-intervention to post-intervention are shown in the table below. The intervention significantly reduced GI in both the “advantaged & ⩾3 level” and “disadvantaged & ⩾3 level” groups. The intervention did not significantly change any of the nutrient intakes from pre-intervention to post-intervention in the “disadvantaged and <3 level” group. The intervention significantly reduced excess GWG, compared to the control, only among those in the “disadvantaged and ⩾3 level” (31·8 % vs. 69·7 %, respectively; P= 0·006) and “advantaged and ⩾3 level” (34·5 % vs. 55·5 %, respectively; P= 0·001). There were no significant differences in excess GWG between the intervention and control in the “disadvantaged and <3 level” and “advantaged and <3 level”.