Infants born to women following lifestyle advice were significantly less likely to have birth weight above 4.5 kg ( 2.15 % versus 3.69 % ; adjusted risk ratio ( aRR ) = 0.59 ; 95 % confidence interval ( CI ) 0.36 to 0.98 ; P = 0.04 ) , or respiratory distress syndrome ( 1.22 % versus 2.57 % ; aRR = 0.47 ; 95 % CI 0.24 to 0.90 ; P = 0.02 ) , particularly moderate or severe disease , and had a shorter length of postnatal hospital stay ( 3.947.26 days versus 4.419.87 days ; adjusted ratio of means 0.89 ; 95 % CI 0.82 to 0.97 ; P = 0.006 ) compared with infants born to women who received Standard Care .