Determinants of low birth weight: methodological assessment and meta-analysis.

Many investigators increased the number of sources of data on each who studied the causes of prematurity or IUGR have factor, and the number of reports examined for all the included conditions such as toxaemia, pregnancy- factors was therefore much greater than the number related hypertension, abruptio placentae, placenta of individual studies. [...] The sex of the fetus is probably the Other vitamins and trace elements 12 easiest of the factors to evaluate. [...] Thus the The best data comparing birth weights of babies risk of IUGR appears to be elevated in Indians and born to mothers of Indian or Pakistani origin and Pakistanis and reduced in North-African Sephardic those of native Caucasians come from studies carried Jews and North American Indians, but residual out in the United Kingdom. [...] Since pre-pregnancy weight appears to affect Only one of the 14 SM and none of 13 PM studies gestational age, or at least the risk of prematurity, included well-controlled data on the effect of pre- gestational age should be controlled in assessing pregnancy weight on gestational age (31): pre- any effect on birth weight. [...] This study reported that the smaller than those of maternal size, which is exactly sisters of mothers who had IUGR infants tend also to what we would expect, considering the important have babies of lower gestational-age-specific birth contribution of the mother's size and nutritional weight percentile than the sisters of mothers of stores to the intrauterine environment.