The influence of maternal passive and light active smoking on intrauterine growth and body composition of the newborn.

OBJECTIVE: To assess the influence of passive and light active smoking on the reduction of intrauterine growth of the foetus and on modifications in the body composition of the newborn.
DESIGN: Random.
SETTING: Full term newborn infants at the Department of the Pediatric and Gynaecological Divisions of the City Major Hospital, Chair of Paediatrics, Verona University.
SUBJECTS: One hundred and twelve mothers selected after having completed a questionnaire on smoking habits during pregnancy. One hundred and twelve newborn infants were divided into three groups: Group 1: non-smoking and non-exposed mothers; Group 2: non-smoking but exposed mothers; Group 3: light smoking mothers (under 10 cigarettes/d, whether or not also exposed to passive smoking). Examination within 24 h of birth established the anthropometric measurements and estimates of body composition through indices or equations.
RESULTS: Newborns of groups 2 and 3 had a statistically significant reduction of fat mass and most anthropometric measurements: fat mass according to Dauncey (P < 0.001), birth-weight (P < 0.013), crownheel length (P < 0.000), upper- and lower-arm length (P < 0.000) and circumference (P < 0.002), triceps skinfold and sum of all skinfolds (P < 0.004). Student t-test, between groups 2 and 3, did not evidence intergroup differences.
CONCLUSIONS: Exposure of the foetus to passive and/or light active smoking involves a reduction of most auxiological parameters and not only weight. As regards body composition, smoking appears to reduce fat mass. The prevention of smoking during pregnancy is therefore extremely important, as intrauterine growth seems to be negatively influenced not only by active smoking, but also by passive and light active smoking.