Fetal undernutrition affects large numbers of infants in developing countries, with adverse consequences for their immediate survival and lifelong health. It manifests as intrauterine growth retardation (IUGR), defined as birth weight <10th percentile, which probably underestimates the number failing to achieve full growth potential. Birth weight is a crude measure of the dynamic process of fetal growth and does not capture effects of fetal undernutrition on body composition and the development of specific tissues. The link between maternal nutrition and fetal nutrition is indirect. The fetus is nourished by a complex supply line that includes the mother's diet and absorption, endocrine status and metabolism, cardiovascular adaptations to pregnancy and placental function. Micronutrients are essential for growth, and maternal micronutrient deficiency, frequently multiple in developing countries, may be an important cause of IUGR. Supplementation of undernourished mothers with micronutrients has several benefits but there is little hard evidence of improved fetal growth. However, this has been inadequately tested. Most trials have only used single micronutrients and many were inconclusive because of methodological problems. Several food-based studies (some uncontrolled) suggest benefits from improving maternal dietary quality with micronutrient-dense foods. One trial of a multivitamin supplement (HIV-positive mothers, Tanzania) showed increased birth weight and fewer fetal deaths. Well-conducted randomized controlled trials of adequate sample size and including measures of effectiveness are needed in populations at high risk of micronutrient deficiency and IUGR and should include food-based interventions and better measurements of fetal growth, maternal metabolism, and long-term outcomes in the offspring.

Abstract-Data on the early life origins of adult hypertension have been widely reported: however, recent research shows that the strength of association between small size at birth and higher blood pressure weakens as study size increases.In this article, we retest the association between birth weight and systolic blood pressure in a large cohort, examine whether age interacts with birth weight to predict blood pressure, and explore reasons why birth weight-blood pressure associations tend to weaken with increasing study size. Key Words: blood pressure Ⅲ epidemiology Ⅲ infant nutrition Ⅲ blood pressure determination T he "fetal origins" hypothesis suggests that "insults" at critical periods during fetal development can lead to permanent metabolic and structural changes in the fetus increasing the risk of many diseases in adulthood. 1 One key finding in support of this hypothesis is the observation, now replicated in many populations, that lower birth weight is associated with higher adult systolic blood pressure (SBP) 1,2 : an association observed independently of socioeconomic position. 3 Surprisingly, despite the wealth of literature in this field, the precise nature of the association between birth weight and blood pressure remains contentious.One important area of recent debate has focused on the strength of association between birth weight and blood pressure. In the most recent systematic review, Huxley et al 4 concluded that birth weight had little relevance in determining blood pressure levels in later life. This finding was at odds with previous systematic reviews, which have suggested that SBP decreases by between 2 and 4 mm Hg for each 1-kg increase in birth weight. 5,6 Central to the argument put forward by Huxley et al 4 was that after ordering studies by statistical size (derived from the inverse of the variance of the regression coefficient), a clear trend (PϽ0.0001) was observed toward weaker associations between birth weight and blood pressure in the larger studies. In small studies (typically with Ͻ1000 participants), a 1-kg increase in birth weight was associated with a 1.9 mm Hg decrease in SBP, whereas in large studies (typically with Ͼ3000 participants), SBP was reduced by only 0.6 mm Hg/kg. Huxley et al 4 suggested that this was evidence of publication bias, with smaller studies being more likely to be published if they found strong inverse birth weight-blood pressure associations. 7 The authors argued that because larger studies are known to be less prone to publication bias, a decrease of 0.6 mm Hg/kg was nearer to the true association. An additional contentious area in the literature has been the actual nature of the association between birth weight and blood pressure. Even within the large studies reviewed by Huxley et al, 4 the association was inconsistent, with some large studies reporting a perfectly linear association across the birth weight continuum 8 and others reporting a reverse J-shape pattern, whereby those individuals with the highest birth weight also tended toward slightly...

Background-The majority of studies investigating the association between birth weight and adult total cholesterol (TC) concentration have been small and underpowered: not surprisingly, the findings have been inconsistent. We aimed to determine whether birth weight predicted adult TC in a large sample population. Methods and Results-Between 1994 and 1996, 132 000 British Telecom employees undertook voluntary occupational health screening. Birth weight and lifestyle factors were self-reported; TC concentration and body size were measured by occupational health nurses. Complete measurements were available for 18 286 men and 7557 women (age range, 17 to 64 years). We found that sex and birth weight significantly interacted to predict adult TC (birth weight/sex interaction term, Pϭ0.002). In men, lower birth weight was associated with higher adult TC levels (a Ϫ0.07 reduction in TC for each 1-kg increase in birth weight; 95% CI, Ϫ0.09 to Ϫ0.04 mmol/L; PϽ0.001), whereas no association was observed in women. Adjustment for potential confounding factors, including current body size and menopausal status, did not alter the findings. Analysis by SD score showed that in men, a 1-SD decrease in body mass index lowered TC concentration Ϸ5-fold more than a 1-SD increase in birth weight. Conclusions-This is the largest study to investigate the association between birth weight and TC and suggests that the association may be dependent on sex. The absence of an association in women was not explained by menopausal status. The influence of fetal environment on adult TC is small compared with the influence of adult adiposity. (Circulation.