Growth Trajectories in Children of Mothers with Eating Disorders Institute of Psychiatry, Kings College London Abigail Easter

Eating Disorders Anorexia Nervosa (AN) – BMI<17.5 & intense fear of fatness Bulimia Nervosa (BN) – Recurrent binge eating & compensatory behaviours Eating Disorder not Otherwise Specified (EDNOS) Prevalence rates: AN - 0.3% BN - 1% EDNOS - 5-7%

Feeding & Diet Breastfeeding has been found to be more problematic in women with ED Higher rates of feeding difficulties identified: Small quantity feeding/not satisfied after feeding Refusal to take solids (Micali, 2009) Mothers with ED display: more restrictive feeding styles higher levels of conflict at mealtime tend to hold more distorted perceptions of their childs weight and shape (Stein, 1994;1999)

Growth Problems Intrauterine growth restriction at birth (Treasure & Russell 1988) 140 mothers with AN 28% had feeding and weight difficulties 17% reported failure to thrive within their first year of life (Brinch Isager & Tolstrup, 1988) lower weight gain at 1 yr in infants of ED women but, no differences at 10 yrs of age (Stein et al.,1994; 2006) Children of women with BN more likely to be overweight at 9 months (Micali, 2009)

Aims 1. to determine whether the growth trajectories, from birth-10 yrs, differ between infants of women with and without ED 2. to establish if childhood growth trajectories vary across maternal ED classification 3. to establish if growth trajectories in children of women with ED differ from women with other psychiatric disorders (OPD)

Sample: Avon Longitudinal Study of Parents & Children (ALSPAC) 14,472 women enrolled at 8 weeks gestation At 12 weeks gestation asked: have you ever had: anorexia nervosa or bulimia nervosa? women divided according to lifetime Eating Disorders: AN: n=247 BN: n=194 AN+BN: n= 82 2 Control Groups control groups: Remaining sample: n=10,461 other psychiatric disorders (OPD): n=1,148

Sample Characteristics No EDANBNAN+BNOPD N (%) 9, Male offspring, (%) Maternal parity, Multiparous (%) 55%52.4%51.5%53.2%59.1% * Maternal BMI (kg/m 2 ), mean * *23.1 Maternal age (years) **: p< 0.01, *: p<0.05

Height and Weight Measures in ALSPAC 1. Obstetric records & ALSPAC staff 2. Routine child health records 3. Research clinics - CiF and Focus 4. Questionnaires - mother-reports Height: birth-10 years (cm) Pondral Index (PI): birth - 2 years (kg/m 3 ) Body Mass Index (BMI): 2-10 years (kg/m 2 )

Data Available No EDANBNAN+BNOPD Height Boys Girls N= N= N= N= N= PI Boys Girls BMI Boys girls

Statistical Methods 1. Fractional Polynomial were used to estimate overall shape of curves for height, PI and BMI (Royston et al. 1999) 1. Random effects models (MLwiN) to predict growth across groups 2. Boys and girls modelled separately 3. Z-tests to assess group differences Confounders: Gestational age, maternal age, maternal education, family income and parity Mediators: maternal pre-pregnancy BMI and smoking during pregnancy (Howe et al, 2010 )

Boys Height: Mean difference from controls **: p< 0.01, *: p<0.05 Adjusted for confounders Height (cm) No EDANBNAN+BNOPD Birth * 1 year * 2 years * 5 years * 10 years *

Girls Height Mean difference from controls **: p< 0.01, *: p<0.05 Adjusted for confounders Height (cm) No EDANBNAN+BNOPD Birth * year years years years

Boys PI/BMI: Mean difference from controls **: p< 0.01, *: p<0.05 Adjusted for confounders No EDANBNAN+BNOPD PI (kg/m 3 ) N=4537N=73N=84N=38N=496 Birth year * BMI (kg/m 2 ) N=4271N=68N=78N=35N=452 2 years years * * years

BMI Trajectories Boys

Girls PI/BMI: Mean difference from controls ***: p<0.001, **: p< 0.01, *: p<0.05 Adjusted for confounders No EDANBNAN+BNOPD PI (kg/m 3 )N=4363N=64N=81N=30N=424 Birth * year BMI (kg/m 2 ) N=4117N=61N=78N=29N=398 2 years years * 10 years *

BMI Trajectories: Girls

Summary of Findings Boys of women with ED: taller than children in unexposed group higher BMI trajectories from 2-5 in contrast, children of women with other psychiatric disorders shorter throughout childhood similar BMI trajectories throughout childhood

Summary of Findings Girls of women with ED: AN shorter throughout childhood Lower BMI in in early childhood but catch up BN higher PI at birth with other psychiatric disorders shorter, but higher BMI from 5 years onwards

Conclusions Children of mothers with ED have different BMI trajectories, particularly in early – middle childhood Male children of women with ED tend to be taller/have higher Female children of women with ED tend to be shorter with lower BMI Modelling of growth in children of women with ED later in childhood will be important

Strengths & Limitations Strengths longitudinal large cohort large number of measurements Limitations self reported ED status small numbers in ED groups – lacking power

Acknowledgements Nadia Micali Laura Howe Janet Treasure Ulrike Schmidt Kate Tilling Kate Northstone