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

child’s 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 ED AN BN AN+BN OPD

N (%) 9,847 165 184 75 1085

Male offspring,

(%)51.2 51.4 49.7 51.2 53

Maternal parity,

Multiparous (%)55% 52.4% 51.5% 53.2% 59.1% *

Maternal BMI

(kg/m2), mean

22.9 21.4 * 23.1 21.4 * 23.1

Maternal age (years) 28.2 28.9 28.2 29.2 28

**: 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/m2)

Data Available

No ED AN BN AN+BN OPD

Height

Boys

Girls

N=

4588

4416

N=

74

65

N=

85

82

N=

38

30

N=

501

432

PI

Boys

Girls

4537

4363

73

64

84

81

38

30

496

424

BMI

Boys

girls

4271

4117

68

61

78

78

35

29

452

398

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 ED AN BN AN+BN OPD

Birth 50.26 +0.137 +0.174 -0.102 -0.198 *

1 year 76.10 +0.327 +0.051 -0.094 -0.284 *

2 years 87.32 +0.400 +0.011 -0.095 -0.323 *

5 years 110.22 +0.391 +0.151 -0.173 -0.416 *

10 years 140.68 -0.716 +1.883 * -0.814 -0.643

Girls’ Height Mean difference from controls

**: p< 0.01, *: p<0.05 Adjusted for confounders

Height (cm) No ED AN BN AN+BN OPD

Birth 49.73 -0.471* -0.078 +0.231 -0.161

1 year 74.25 -0.265 +0.048 -0.732 -0.184

2 years 85.63 -0.240 +0.020 -0.931 -0.184

5 years 109.61 -0.309 -0.184 -0.937 -0.168

10 years 138.86 -0.572 -0.648 -0.324 -0.121

Boys’ PI/BMI:Mean difference from controls

**: p< 0.01, *: p<0.05 Adjusted for confounders

No ED AN BN AN+BN OPD

PI (kg/m3) N=4537 N=73 N=84 N=38 N=496

Birth 26.19 -0.428 -0.277 +0.069 +0.127

1 year 23.33 -0.119 +0.406 +0.270 +0.216 *

BMI

(kg/m2)N=4271 N=68 N=78 N=35 N=452

2 years 16.80 +0.099 +0.260 +0.316 +0.155

5 years 15.93 +0.339 * +0.122 +0.491 * -0.024

10 years 17.65 +0.090 +0.119 +0.084 +0.093

BMI TrajectoriesBoys

1616

.517

17.5

18B

MI (

kg/m

2)

24 48 72 96 120age (months)

Controls AnnorexiaBulimia Annorexia and bulimiaOther psychiatric

Boys' BMI

Girls’ PI/BMI:Mean difference from controls

***: p<0.001, **: p< 0.01, *: p<0.05 Adjusted for confounders

No ED AN BN AN+BN OPD

PI (kg/m3) N=4363 N=64 N=81 N=30 N=424

Birth 26.24 -0.070 +0.480 * -0.162 -0.090

1 year 23.24 +0.397 +0.061 +0.386 -0.220

BMI

(kg/m2)N=4117 N=61 N=78 N=29 N=398

2 years 16.61 -0.346 +0.297 +0.249 -0.075

5 years 15.98 -0.011 +0.258 +0.324 +0.157 *

10 years 18.07 +0.025 -0.285 -0.516 +0.561 *

BMI Trajectories:Girls

1617

1819

BM

I (kg

/m2)

24 48 72 96 120age (months)

Controls AnnorexiaBulimia Annorexia and bulimiaOther psychiatric

Girls' BMI

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