Is Mediterranean Diet during pregnancy protective for fetal growth restriction? Results from two prospective cohort studies in Spain and Greece Leda Chatzi, Michelle Mendez, Raquel Garcia, Theano Roumeliotaki, Jesús Ibarluzea, Adonina Tardón, Pilar Amiano, Aitana Lertxundi, Carmen Iñiguez, Jesus Vioque, Manolis Kogevinas, Jordi Sunyer On behalf of the INMA and the RHEA birth cohorts study groups British Journal of Nutrition, 2011

Diet in pregnancy “It is certain that the significance of correct nutrition in child-bearing does not begin in pregnancy itself or even in the adult female before pregnancy. It looms large as soon as a female child is born and indeed in its intrauterine life.”. Edward Mellanby, 1933

Mediterranean Diet Trichopoulou, 2003

Research Hypotheses/Aims of the study: To determine prospectively the association between adherence to the Mediterranean Diet in pregnancy and fetal growth in the two large population based mother- child cohorts in the Mediterranean area (INMA and RHEA mother-child cohorts)

Diet assessment The “Rhea” FFQ: FFQ on 250 items, 17 food groups, completed by personal interview in mid pregnancy (14th-18th week of gestation) Frequency of consumption: per day, week, and/or per month. Photographs were used to visualize small, medium and large portion sizes for each food item Mixed dishes: standard recipes were used when available, otherwise new recipes that matched the description of the food were made and the intake of foods from different items was aggregated. Nutrient analysis: Based on the UK Nutrient Databank (McCance and Widdowson's, 6th edition 2002). The Greek Mother & Child Cohort Study

INMA STUDY INMA Atlantic INMA Mediterranean

The Greek Mother & Child Cohort Study INMA STUDY Diet assessment The “INMA” FFQ: FFQ on 100 items, to assess usual food and nutrient intakes during the first trimester of pregnancy Frequency of consumption: 9 possible intake frequency categories, ranging from “never or less than once per month” to “6 or more times per day.” Standard units or reference serving sizes were specified for each food item. Nutrient analysis: Primarily obtained from the US Department of Agriculture food-composition tables and other published sources.

Maternal adherence to the Mediterranean Diet during pregnancy Med Diet Score (adapted from Trichopoulou et al) Protective compounds: +1 if equal or above median intake Fruits and nuts, vegetables, legumes, fish, cereals, dairy products, Detrimental compounds: 0 if equal or above median Meat Fat intake: Ratio of daily consumption of monounsaturated lipids to saturated lipids Not included in the index: Alcohol consumption The INMA and Rhea Mother & Child Cohort Studies

Fetal Growth Assessment Anthropometric measures at birth: Birth weight (BW), birth length (BL), head circumference (HC), Fetal growth restriction: customized definition of impaired growth taking into account constitutional characteristics (gest age; parental anthropometry; primiparous mother; infant sex) The INMA and Rhea Mother & Child Cohort Studies

Potential Confounders  Maternal, Paternal age,  Maternal, Paternal social class and education,  Maternal pre-pregnancy BMI (kg/m2),  Maternal smoking during pregnancy,  Parity  Supplement use during pregnancy,  Alcohol intake during pregnancy,  Total Energy Intake during pregnancy The INMA and Rhea Mother & Child Cohort Studies

Statistical analysis The exposure variable of interest: Mediterranean Diet Score The outcome variable of interest: Birth weight (BW), birth length (BL), head circumference (HC), and foetal growth restriction. All variables related with the outcome in the bivariate models (p<0.2) were included in the multivariable models Multivariable log-binomial and linear regression models performed after adjusting for confounders Evaluation of effect modification (likelihood ratio test (a=0.1) The INMA and Rhea Mother & Child Cohort Studies

Food groups intake during pregnancy The INMA and Rhea Mother & Child Cohort Studies Median intake (g/day) Cereals Vegetables Legumes Fruits and nuts Fish and seafood Monounsaturated fatty acids Saturated fatty acids Dairy products Meat INMA AtlanticINMA MediterraneanRHEA

Mediterranean Diet Score during pregnancy The INMA and Rhea Mother & Child Cohort Studies Mean (95% C.I.) Frequency % Diet Score of 0-3 Diet Score of 4-5 Diet Score of 6-8 INMA Atlantic INMA Mediterranean RHEA INMA AtlanticINMA MediterraneanRHEA

All models were adjusted for gender, gestational age, maternal smoking during pregnancy, maternal age and total energy intake using linear regression models. a P values for values for each component from the regression model b Also adjusted for: INMA Atlantic: parity, maternal BMI, paternal education and parental social class; INMA Mediterranean: parity, parental BMI, and maternal social class; RHEA: maternal BMI and education. c Also adjusted for: INMA Atlantic: parity, maternal BMI, paternal age and maternal social class; INMA Mediterranean: parity, maternal BMI, and maternal social class; RHEA: maternal height and education. d Also adjusted for: INMA Atlantic: parity, maternal BMI and education; INMA Mediterranean: parity, maternal BMI, maternal education and alcohol intake; RHEA: maternal BMI and education. * Mediteranean Diet score, Low: 0-3; Medium: 4-5; High: 6-8 Associations between Mediterranean Diet Score in pregnancy with anthropometric measurements at birth The INMA and Rhea Mother & Child Cohort Studies INMA AtlanticINMA MediterraneanRHEA βSEPaPa β PaPa β PaPa Weight b MD score, LowRef. MD score, Medium-26·4626·030·31055·2023·520·019-33·6731·780·290 MD score, High-82·8547·670·08287·7833·400·009-20·4242·330·630 Length c MD score, LowRef. MD score, Medium-0·160·120·1850·130·100·203-0·430·180·077 MD score, High-0·250·220·2450·300·150·040-0·060·240·794 Head circumference d MD score, LowRef. MD score, Medium0·030·090·7700·030·070·647-0·230·120·049 MD score, High-0·060·160·7110·160·100·121-0·200·160·214

Associations between Mediterranean Diet Score* in pregnancy with Foetal Growth Restriction (FGR) The INMA and Rhea Mother & Child Cohort Studies INMA AtlanticINMA MediterraneanRHEA RR95% CIPaPa RR95% CIPaPa RR95% CIPaPa FGR in Weight b MD score, Low Ref MD score, Medium 1·240·81, 1·890·3290·760·54, 1·060·1091·820·95, 3·490·071 MD score, High 0·970·42, 2·260·9430·500·28, 0·900·0211·960·90, 4·250·089 FGR in Length c MD score, Low Ref MD score, Medium 1·330·87, 2·040·1891·010·70, 1·470·9521·390·72, 2·680·330 MD score, High 0·630·23, 1·760·3760·950·55, 1·620·8380·900·35, 2·300·821 FGR in Head circumference d MD score, Low Ref MD score, Medium 0·880·57, 1·340·5431·150·80, 1·650·4591·630·89, 2·960·112 MD score, High 1·110·53, 2·330·7791·070·63, 1·830·8001·640·76, 3·560·211 All models were adjusted for maternal smoking during pregnancy, maternal age and total energy intake a P values for each component from the log-binomial model. b Also adjusted for: INMA Atlantic: maternal social class; INMA Mediterranean: maternal BMI and maternal social class; RHEA: paternal age and maternal education. c Also adjusted for: INMA Atlantic and INMA Mediterranean: maternal education; RHEA: paternal education. d Also adjusted for: INMA Atlantic: paternal age, maternal BMI and education; INMA Mediterranean: maternal BMI, alcohol intake, education and social class; RHEA: maternal alcohol intake and education. * Mediteranean Diet score, Low: 0-3; Medium: 4-5; High: 6-8

Adjusted means of birth weight by Mediterranean Diet Score and maternal smoking during pregnancy The INMA and Rhea Mother & Child Cohort Studies MedDiet 0-3MedDiet 4-6MedDiet 6-8 Weight (gr) INMA-Atlantic: Non Smokers (○), Smokers (●); INMA-Mediterannean: Non Smokers (□), Smokers (■); RHEA: Non Smokers (  ), Smokers (  ). All models were adjusted for maternal age and total energy intake, gender and gestational age. Models for weight were also adjusted for: INMA-Atlantic: parity, maternal BMI, paternal education and parental social class; INMA-Mediterannean: parity, parental BMI, and maternal social class; RHEA: maternal BMI and education.

Adjusted means of head circumference by Mediterranean Diet Score and maternal smoking during pregnancy The INMA and Rhea Mother & Child Cohort Studies MedDiet 0-3MedDiet 4-6MedDiet 6-8 Head circumference (cm) INMA-Atlantic: Non Smokers (○), Smokers (●); INMA-Mediterannean: Non Smokers (□), Smokers (■); RHEA: Non Smokers (  ), Smokers (  ). All models were adjusted for maternal age and total energy intake, gender and gestational age. Models for head circumference were also adjusted: INMA-Atlantic: parity, maternal BMI and education; INMA-Mediterranean: parity, maternal BMI, maternal education and alcohol intake; RHEA: maternal BMI and education.

Population based cohort design. Customised definition of “foetal growth restriction” Detailed data for dietary intake during pregnancy; Total energy intake Multivariate analysis; exclusion criteria Self-reported diet during pregnancy Unknown confounding factors linked both with fetal growth and diet during pregnancy that could explain this association StrengthsLimitations Strengths and limitations of the present study

Conclusions.. MD during pregnancy is not homogeneous within the Mediterranean area. A high adherence to MD may modify the detrimental effect of smoking on birth size. Complex underlying processes explain findings The INMA and Rhea Mother & Child Cohort Studies

The Greek Mother & Child Cohort Study to be continued …………… To be continued…