A negative association was found for gestational age ( -2.33 ; 95 % CI -3.81 to -0.85 ; p = 0.002 ) , birth weight ( -0.01 ; 95 % CI -0.02 to -0.01 ; p < 0.001 ) and milk volume at study enrollment ( -0.02 ; 95 % CI -0.05 to -0.01 ; p = 0.01 ) .