1. Breastfeeding for six months is an independent association of language and cognitive intelligence in infants at 18 months.
Sonia Kua1, Julie Qunilivan1,2,3
1. Joondalup Health Campus, Joondalup, Australia
2. Women’s and Children’s Health Research Institute, University of Adelaide, Australia
3. University of Notre Dame Australia Institute Health Research, Fremantle, Australia

2. Background WHO recommends exclusive breastfeeding for ≥6 months
High rates of initiation (92.3%) in Australia, however only 50% are still breastfeeding at 6 months
Multiple benefits to both mother and baby
Research suggests positive association between breastfeeding and IQ
Long chain polyunsaturated fatty acids (DHA, AA)
Demographic, social and maternal factors
Quality of available studies
Small and lacking power
Those demonstrating largest benefit do not confound for maternal education and IQ
Hora, Victora WHO 2013
ABS
Capsi et al. PNAS 2007, 104(47)
Der et al. BMJ 2006,333:945

3. Methods
Prospective multicentre Australian study using subset of patients from the DOMINO trial
Antenatal questionnaire
EPDS, Maternal Social Support Index, pregnancy and delivery data
Breastfeeding status at 6 weeks and 6 months
Bayley Scales for Infant Development at 18 months ‪

4. Results 637 infants underwent BSID-II assessment at 18 months
201 (31.5%) exclusively breastfed for 6 months
76 (12%) partially breastfed
360 (56.5%) formula fed
No significant antenatal, delivery or postnatal differences between women who breastfed exclusively compared to partially.
Exclusive vs formula feeding
Older
More educated
Non smokers
Higher birthweight babies
High social support scores
Lower EPDS scores ‪

5. Results – Univariate Exclusive vs Partial Breastfeeding
Exclusive Breastfeeding
Partial Breastfeeding
P-value
OR (95% CI)
Age mean (SD)
30.01 (5.50)
29.82 (5.29)
0.79
Completed secondary school (%)
159 (79%)
55 (72%)
0.30
0.69 ( )
Further study (%)
155 (77%)
54 (71%)
0.37
0.73 ( )
Smoker (%)
33 (16%)
19 (25%)
0.14
1.70 ( )
Low social support score (%)
51 (25%)
24 (32%)
0.38
1.36 ( )
Postnatal depression(%)
37 (18%)
19 (25%)
0.29
1.48 ( )

6. Results –Univariate Exclusive Breastfeeding vs Formula
P-value
OR (95% CI)
Age mean (SD)
30.01 (5.50)
28.16 (5.85)
0.0002
Completion secondary school (%)
159 (79%)
182 (51%)
<0.0001
0.27 ( )
Further study (%)
155 (77%)
224 (62%)
0.0004
0.49 ( )
Smoker (%)
33 (16%)
147 (41%)
3.51 ( )
Low social support score (%)
51 (25%)
121 (34%)
0.05
1.49 ( )
Postnatal depression (%)
37 (18%)
109 (30%)
0.003
1.92 ( )

7. Results - Bayley Neurodevelopmental Scores: Exclusive BF vs Formula
‪learn-your-iq.com
Breastfeeding
Formula Feeding
P value
Cognitive mean (SD)
104.6 (13)
100.9 (11)
0.0007
Language mean (SD)
(14)
96.5 (14)
0.0004
Motor mean (SD)
(11)
102.4 (11)
0.22

8. Results – Multivariate analysis of Cognitive Bayley scores
Significant associations and predictors
P>z
Difference (95% CI)
COGNITIVE
Exclusive breastfeeding 6 months
0.005
+0.56 (+0.34 to +0.78)
Completed 20 education
<0.0001
(+1.41 to +2.39)
Further education
+3.0 (+2.11 to +3.89)
Birth weight
0.0007
+1.65 (+1.35 to +1.95)
Postnatal depression
0.009
-0.89 (-1.46 to -0.32)
Infant gender male
0.006
-0.64 (-0.95 to -0.33)
Preterm
-2.11 (-2.69 to -1.53)

9. Results – Multivariate analyses of Language Bayley Scores
Significant associations and predictors
P>z
Difference (95% CI)
LANGUAGE
Exclusive breastfeeding 6 months
0.0001
+0.60 (+0.31 to +0.89)
Completed 20 education
0.0005
+1.85 (+1.31 to +2.39)
Further education
<0.0001
+3.42 (+3.01 to +3.83)
Birth weight
0.0008
+1.94 (+1.54 to +2.34)
Postnatal depression
0.0007
-1.51 (-1.94 to – 1.08)
Infant gender male
-2.27 (-2.69 to -1.85)
Preterm
-2.10 (-1.88 to -2.32)

10. Results – Multivariate analyses of Motor Bayley Scores
Significant associations and predictors
P>z
Difference (95% CI)
MOTOR
Birth weight
0.003
+0.39 (+0.19 to +0.59)
Infant gender male
0.04
+0.21 (+0.06 to 0.36)
Preterm
0.001
+0.43 (+0.24 to +0.63)

11. Discussion
Results similar to those in other studies in which confounding variables have been considered.
Most important influence on infant IQ is maternal education.
Other significant variables are maternal variables of further education and depression and infant variables of gender, birthweight and prematurity.
No significant difference between exclusive and partial breastfeeding.
Dose response relationship?
Guxens et al. Pediatrics 2011,128:880
Whitehouse et al. Paediatr Perinat Epidemiol. 2010,25:44.
‪www3.gehealthcare.com

12. Discussion Infant verbal IQ and breastfeeding
Nutritive constituents
Positive parenting behaviours
Increased contact between mother and infant
Persistence of positive effects from breastfeeding into later years
Kramer et al Arch Gen Psychiatry. 2008,65(5):578
Gibson-Davis. Pediatrics. 2006,118(5):1444
Eriksen et al. PLOS ONE. 2013,8(11):79200
‪blog.kidville.com

13. Conclusion
Increasing evidence that breastfeeding is associated with improved neurodevelopmental outcomes for offspring.
Subsequent studies could also assess for specific maternal IQ scores
Need for encouraging persistence of breastfeeding to six months ‪