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

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 2011-12 Capsi et al. PNAS 2007, 104(47) Der et al. BMJ 2006,333:945

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 ‪www.virginiamidwife.com

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 ‪www.mumsgone2aus.com

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 (0.38-1.23) Further study (%) 155 (77%) 54 (71%) 0.37 0.73 (0.40-1.32) Smoker (%) 33 (16%) 19 (25%) 0.14 1.70 (0.90-3.22) Low social support score (%) 51 (25%) 24 (32%) 0.38 1.36 (0.76-2.42) Postnatal depression(%) 37 (18%) 19 (25%) 0.29 1.48 (0.79-2.77)

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 (0.18-0.40) Further study (%) 155 (77%) 224 (62%) 0.0004 0.49 (0.33-0.72) Smoker (%) 33 (16%) 147 (41%) 3.51 (2.29-5.39) Low social support score (%) 51 (25%) 121 (34%) 0.05 1.49 (1.01-2.19) Postnatal depression (%) 37 (18%) 109 (30%) 0.003 1.92 (1.26-2.93)

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) 101.0 (14) 96.5 (14) 0.0004 Motor mean (SD) 103.7 (11) 102.4 (11) 0.22

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 +1.90 (+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)

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)

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)

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

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

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 ‪www.telegraph.co.uk