Weight gain in pregnancy, triceps skinfold thickness, and blood pressure in offspring

Maternal pregnancy weight or gestational weight gain and offspring's blood pressure: A systematic review

AIMS

An increasing number of studies suggest that maternal weight parameters in pregnancy are associated with offspring's blood pressure (BP). The aim of this systematic review - following the updated Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) Statement - was to assess and judge the evidence for an association between maternal pregnancy weight/body mass index (BMI) or gestational weight gain (GWG) with offspring's BP in later life.

DATA SYNTHESIS

MEDLINE, EMBASE, Cochrane Library, CINAHL and Web of Science were searched without limits. Risk of bias was assessed using the "US National Heart, Lung and Blood Institute"-tool, and an evidence grade was allocated following the "World Cancer Research Fund" criteria. Of 7,124 publications retrieved, 16 studies (all cohort studies) were included in the systematic review. Overall data from 52,606 participants (0 years [newborns] to 32 years) were enclosed. Association between maternal pregnancy BMI and offspring's BP were analyzed in 2 (both "good-quality" rated) studies, without consistent results. GWG and offspring's BP was analyzed in 14 studies (2 "good-quality", 9 "fair-quality", 3 "poor-quality" rated). Of these, 3 "fair-quality" studies described significant positive results for systolic BP and significant results, but partly with varying directions of effect estimates for diastolic BP. Mean arterial pressure (MAP) was analyzed in 1 "poor-quality" congress paper. Overall, based on the small number of "good-quality"-rated studies and the inconsistency of effect direction, no firm conclusion can be drawn.

CONCLUSION

Evidence for an association of maternal pregnancy weight determinants with offspring's BP was overall graded as "limited - no conclusion".

Maternal overnutrition elevates offspring's blood pressure-A systematic review and meta-analysis

BACKGROUND

Maternal overnutrition during pregnancy predisposes the offspring to cardiometabolic diseases.

OBJECTIVES

This systematic review and meta-analysis aimed to investigate the association between maternal overnutrition and offspring's blood pressure (BP) and the effect of offspring's obesity on this association.

DATA SOURCES

PubMed, EMBASE, Clinicaltrials.gov, CENTRAL.

STUDY SELECTION AND DATA EXTRACTION

Human studies published in English before October 2021 were identified that presented quantitative estimates of association between maternal overnutrition just before or during pregnancy and the offspring's BP.

SYNTHESIS

Random-effect model with the DerSimonian and Laird weighting method was used to analyse regression coefficients or mean differences.

RESULTS

After selection, 17 observational studies (140,517 mother-offspring pairs) were included. Prepregnancy body mass index (ppBMI) showed positive correlation with BP in offspring (regression coefficient for systolic: 0.38 mmHg per kg/m² , 95% confidence interval (CI) 0.17, 0.58; diastolic: 0.10 mmHg per kg/m² , 95% CI 0.05, 0.14). These indicate 1.9 mmHg increase in systolic and 0.5 mmHg increase in diastolic BP of offspring with every 5 kg/m² gain in maternal ppBMI. Results on coefficients adjusted for offspring's BMI also showed association (systolic: 0.08 mmHg per kg/m² , 95% CI 0.04, 0.11; diastolic: 0.03 mmHg per kg/m² , 95% CI 0.01, 0.04). Independent from ppBMI, gestational weight gain (GWG) showed positive correlation with systolic BP (systolic BP: 0.05 mmHg per kg, 95% CI 0.01, 0.09), but not after adjustment for offspring's BMI. Mean systolic BP was higher in children of mothers with excessive GWG than in those of mothers with optimal GWG (difference: 0.65 mmHg, 95% CI 0.25, 1.05).

CONCLUSIONS

Independent from offspring's BMI, higher prepregnancy BMI may increase the risk for hypertension in offspring. The positive association between GWG and offspring's systolic BP is indirect via offspring's obesity. Reduction in maternal obesity and treatment of obesity in children of obese mothers are needed to prevent hypertension.

Nutrition for Multiples

In 2012 there were 135,943 infants of multiple pregnancies born in the United States, nearly a 2-fold increase since 1980, with twins accounting for 96% of all multiple births. To date, most perinatal morbidities associated with multiple births have proven resistant to technological or pharmaceutical interventions. Maternal nutrition can have a profound effect on the course and outcome of multiple pregnancy, with the goal of achieving optimal intrauterine growth and birthweights, and minimizing prenatal and perinatal complications for the mother and her children.

Ethnic Differences in Effects of Maternal Pre-Pregnancy and Pregnancy Adiposity on Offspring Size and Adiposity

CONTEXT

Maternal adiposity and overnutrition, both before and during pregnancy, plays a key role in the subsequent development of obesity and metabolic outcomes in offspring.

OBJECTIVE

We explored the hypothesis that maternal adiposity (pre-pregnancy and at 26-28 weeks' gestation) and mid-pregnancy gestational weight gain (GWG) are independently associated with offspring size and adiposity in early childhood, and determined whether these effects are ethnicity dependent.

DESIGN

In a prospective mother-offspring cohort study (N = 976, 56% Chinese, 26% Malay, and 18% Indian), we assessed the associations of offspring size (weight, length) and adiposity (subscapular and triceps skinfolds), measured at birth and age 6, 12, 18, and 24 mo, with maternal pre-pregnancy body mass index (ppBMI), mid-pregnancy GWG, and mid-pregnancy four-site skinfold thicknesses (triceps, biceps, subscapular, suprailiac).

RESULTS

ppBMI and mid-pregnancy GWG were independently associated with postnatal weight up to 2 y and skinfold thickness at birth. Weight and subscapular and triceps skinfolds at birth increased by 2.56% (95% confidence interval, 1.68-3.45%), 3.85% (2.16-5.57%), and 2.14% (0.54-3.75%), respectively for every SD increase in ppBMI. Similarly, a one-SD increase in GWG increased weight and subscapular and triceps skinfolds at birth by 2.44% (1.66-3.23%), 3.28% (1.75-4.84%), and 3.23% (1.65-4.84%), respectively. ppBMI and mid-pregnancy suprailiac skinfold independently predicted postnatal skinfold adiposity up to 2 years of age, whereas only GWG predicted postnatal length. The associations of GWG with postnatal weight and length were present only among Chinese and Indians, but not Malays (P < .05 for interaction).

CONCLUSIONS

ppBMI and GWG are independent modifiable factors for child size and adiposity up to 2 years of age. The associations are ethnic-dependent, and underscore the importance of ethnic specific studies before generalizing the applicability of risk factors reported in other populations.

No association of maternal gestational weight gain with offspring blood pressure and hypertension at age 18 years in male sibling-pairs: a prospective register-based cohort study

BACKGROUND

Maternal gestational weight gain (GWG) is associated with birth weight, obesity, and possibly blood pressure (BP) and hypertension in the offspring. These associations may however be confounded by genetic and/or shared environmental factors. In contrast to previous studies based on non-siblings and self-reported data, we investigated whether GWG is associated with offspring BP and hypertension, in a register-based cohort of full brothers while controlling for fixed shared effects.

METHODS

By using Swedish nation-wide record-linkage data, we identified women with at least two male children (full brothers) born 1982-1989. Their BP was obtained from the mandatory military conscription induction tests. We adopted linear and Poisson regression models with robust variance, using generalized estimating equations to analyze associations between GWG and BP, as well as with hypertension, within and between offspring sibling-pairs.

RESULTS

Complete data on the mothers' GWG and offspring BP was obtained for 9,816 brothers (4,908 brother-pairs). Adjusted regression models showed no significant associations between GWG and SBP (β = 0.03 mmHg per 1-kg GWG difference, [95% CI -0.08, 0.14], or DBP (β = -0.03 mmHg per 1-kg GWG difference [95% CI -0.11, 0.05]), or between GWG and offspring's risk of hypertension (relative risk = 1.0 [95% CI 0.99, 1.02], neither within nor between siblings.

CONCLUSIONS

In this large sibling-pair study, we did not find any significant association between GWG and offspring BP or the risk of hypertension at 18y, when taking genetic and environmental factors shared within sibling pairs into account. Further large sibling studies are required to confirm a null association between GWG and other cardiovascular risk factors.

Programming of fetal insulin resistance in pregnancies with maternal obesity by ER stress and inflammation

The global epidemics of obesity during pregnancy and excessive gestational weight gain (GWG) are major public health problems worldwide. Obesity and excessive GWG are related to several maternal and fetal complications, including diabetes (pregestational and gestational diabetes) and intrauterine programming of insulin resistance (IR). Maternal obesity (MO) and neonatal IR are associated with long-term development of obesity, diabetes mellitus, and increased global cardiovascular risk in the offspring. Multiple mechanisms of insulin signaling pathway impairment have been described in obese individuals, involving complex interactions of chronically elevated inflammatory mediators, adipokines, and the critical role of the endoplasmic reticulum (ER) stress-dependent unfolded protein response (UPR). However, the underlying cellular processes linking MO and IR in the offspring have not been fully elucidated. Here, we summarize the state-of-the-art evidence supporting the possibility that adverse metabolic postnatal outcomes such as IR in the offspring of pregnancies with MO and/or excessive GWG may be related to intrauterine activation of ER stress response.

Ethnic and socioeconomic influences on childhood blood pressure: the Child Heart and Health Study in England

OBJECTIVES

Compared to UK white European adults, UK black African-Caribbean adults have higher mean SBP and DBP; UK South Asian adults have higher mean DBP but lower SBP. Information on blood pressure (BP) in UK children from different ethnic groups is limited. The aim of this study was to compare BP levels in UK children of black African-Caribbean, South Asian and white European origin.

METHODS

BP and body build were measured in 5666 children in a cross-sectional study of UK primary school children of South Asian, black African-Caribbean and white European origin aged 9-10 years. Ethnic and socioeconomic differences in BP were obtained from multilevel linear regression models.

RESULTS

After adjustment for height and adiposity, black African-Caribbean children had lower mean SBP than white Europeans [difference 1.62  mmHg, 95% confidence interval (CI) 0.86-2.38  mmHg], whereas mean DBP was similar (difference 0.58  mmHg, 95% CI -0.12 to 1.28  mmHg). The lower SBP was particularly marked in black African rather than Caribbean children (P  =  0.002). South Asian children had lower mean SBP (difference 1.10  mmHg, 95% CI 0.34-1.86  mmHg) than white Europeans and higher mean DBP (difference 1.07  mmHg, 95% CI 0.37-1.76  mmHg). The higher mean DBP was particularly marked among Indian and Bangladeshi, rather than Pakistani, children (P  =  0.01). BP was unrelated to socioeconomic circumstances; ethnic differences in BP were not affected by socioeconomic adjustment.

CONCLUSION

A BP pattern similar to that in adults is present in UK South Asian but not in UK black African-Caribbean children at 9-10 years.

The risk of maternal obesity to the long-term health of the offspring

The prevalence of maternal obesity has risen dramatically in recent years, with approximately one in five pregnant women in the UK now classed as obese (body mass index ≥ 30 kg/m(2) ) at antenatal booking. Obesity during pregnancy has been hypothesized to exert long-term health effects on the developing child through 'early life programming'. While this phenomenon has been well studied in a maternal undernutrition paradigm, the processes by which the programming effects of maternal obesity are mediated are less well understood. In humans, maternal obesity has been associated with a number of long-term adverse health outcomes in the offspring, including lifelong risk of obesity and metabolic dysregulation with increased insulin resistance, hypertension and dyslipidaemia, as well as behavioural problems and risk of asthma. The complex relationships between the maternal metabolic milieu and the developing foetus, as well as the potential influence of postnatal lifestyle and environment, have complicated efforts to study the programming effects of maternal overnutrition in humans. This review will examine the emerging evidence from human studies linking maternal obesity to adverse offspring outcomes.

Human growth and chronic disease: a memorial to Jim Tanner

CONTEXT

Memorial to Jim Tanner.

OBJECTIVE

To examine the links between early growth and chronic disease in later life.

METHODS

Literature review.

RESULTS

There is now a developmental model for the origins of chronic disease in which the causes to be identified are linked to normal variations in feto-placental, infant and childhood growth and development. These variations lead to variations in the supply of nutrients to the baby that permanently alters gene expression, a process known as 'programming'.

CONCLUSIONS

Variations in the processes of development programme the function of a few key systems that are linked to chronic disease-the immune system, anti-oxidant defences, inflammatory responses, the number and quality of stem cells, neuro-endocrine settings and the balance of the autonomic nervous system. There is not a separate cause for each different disease. Which chronic disease originates during development may depend more on timing than on qualitative differences in exposures to external influences.

Reducing excessive gestational weight gain: lessons from the weight control literature and avenues for future research

Excessive gestational weight gain is a prevalent problem and an independent predictor of future obesity in both mothers and offspring. Intervention research to prevent excessive gestational weight gain is still in its infancy but results to date have been quite modest. Research in weight control outside of pregnancy over the past 30 years has been more robust and identified several key components of effective programs, including use of caloric restriction, daily diet self-monitoring, self-weighing, behavior therapy and ongoing patient-provider contact. The aim of this article is to summarize intervention components shown to be effective in promoting successful weight control outside of pregnancy and explore potential applications in pregnancy. Available evidence suggests that the strategies shown to be effective for weight control outside of pregnancy may also promote better weight control in pregnancy, but several lines for future investigation remain.

Fetoplacental vascular endothelial dysfunction as an early phenomenon in the programming of human adult diseases in subjects born from gestational diabetes mellitus or obesity in pregnancy

Gestational diabetes mellitus (GDM) and obesity in pregnancy (OP) are pathological conditions associated with placenta vascular dysfunction coursing with metabolic changes at the fetoplacental microvascular and macrovascular endothelium. These alterations are seen as abnormal expression and activity of the cationic amino acid transporters and endothelial nitric oxide synthase isoform, that is, the "endothelial L-arginine/nitric oxide signalling pathway." Several studies suggest that the endogenous nucleoside adenosine along with insulin, and potentially arginases, are factors involved in GDM-, but much less information regards their role in OP-associated placental vascular alterations. There is convincing evidence that GDM and OP prone placental endothelium to an "altered metabolic state" leading to fetal programming evidenced at birth, a phenomenon associated with future development of chronic diseases. In this paper it is suggested that this pathological state could be considered as a metabolic marker that could predict occurrence of diseases in adulthood, such as cardiovascular disease, obesity, diabetes mellitus (including gestational diabetes), and metabolic syndrome.

Association of maternal weight gain in pregnancy with offspring obesity and metabolic and vascular traits in childhood

BACKGROUND

We sought to examine the association of gestational weight gain (GWG) and prepregnancy weight with offspring adiposity and cardiovascular risk factors.

METHODS AND RESULTS

Data from 5154 (for adiposity and blood pressure) and 3457 (for blood assays) mother-offspring pairs from a UK prospective pregnancy cohort were used. Random-effects multilevel models were used to assess incremental GWG (median and range of repeat weight measures per woman: 10 [1, 17]). Women who exceeded the 2009 Institute of Medicine-recommended GWG were more likely to have offspring with greater body mass index, waist, fat mass, leptin, systolic blood pressure, C-reactive protein, and interleukin-6 levels and lower high-density lipoprotein cholesterol and apolipoprotein A1 levels. Children of women who gained less than the recommended amounts had lower levels of adiposity, but other cardiovascular risk factors tended to be similar in this group to those of offspring of women gaining recommended amounts. When examined in more detail, greater prepregnancy weight was associated with greater offspring adiposity and more adverse cardiovascular risk factors at age 9 years. GWG in early pregnancy (0 to 14 weeks) was positively associated with offspring adiposity across the entire distribution but strengthened in women gaining >500 g/wk. By contrast, between 14 and 36 weeks, GWG was only associated with offspring adiposity in women gaining >500 g/wk. GWG between 14 and 36 weeks was positively and linearly associated with adverse lipid and inflammatory profiles, with these associations largely mediated by the associations with offspring adiposity.

CONCLUSIONS

Greater maternal prepregnancy weight and GWG up to 36 weeks of gestation are associated with greater offspring adiposity and adverse cardiovascular risk factors. Before any GWG recommendations are implemented, the balance of risks and benefits of attempts to control GWG for short- and long-term outcomes in mother and child should be ascertained.

Pediatric Obesity: It's Time for Prevention before Conception Can Maternal Obesity Program Pediatric Obesity?

Global increases in obesity have led public health experts to declare this disease a pandemic. Although prevalent in all ages, the dire consequences associated with maternal obesity have a pronounced impact on the long-term health of their children as a result of the intergenerational effects of developmental programming. Previously, fetal under-nutrition has been linked to the predisposition to pediatric obesity explained by the adiposity rebound and ‘catch-up’ growth that occurs when a child born to a nutrient deprived mother is exposed to the obesogenic environment of present day. Given the recent increase in maternal overweight/obesity (OW/OB) our attention has shifted from nutrient restriction to overabundance and excess during pregnancy. Consideration must now be given to interventions that could mitigate pregravid body mass index (BMI), attenuate gestational weight gain (GWG) and reduce postpartum weight retention (PPWR) in an attempt to prevent the downstream signaling of pediatric obesity and halt the intergenerational cycle of weight related disease currently plaguing our world. Thus, this paper will briefly review current research that best highlights the proposed mechanisms responsible for the development of child OW/OB and related sequalae (e.g. type II diabetes (T2D) and cardiovascular disease (CVD)) resulting from maternal obesity.

Maternal and child undernutrition: consequences for adult health and human capital

In this paper we review the associations between maternal and child undernutrition with human capital and risk of adult diseases in low-income and middle-income countries. We analysed data from five long-standing prospective cohort studies from Brazil, Guatemala, India, the Philippines, and South Africa and noted that indices of maternal and child undernutrition (maternal height, birthweight, intrauterine growth restriction, and weight, height, and body-mass index at 2 years according to the new WHO growth standards) were related to adult outcomes (height, schooling, income or assets, offspring birthweight, body-mass index, glucose concentrations, blood pressure). We undertook systematic reviews of studies from low-income and middle-income countries for these outcomes and for indicators related to blood lipids, cardiovascular disease, lung and immune function, cancers, osteoporosis, and mental illness. Undernutrition was strongly associated, both in the review of published work and in new analyses, with shorter adult height, less schooling, reduced economic productivity, and--for women--lower offspring birthweight. Associations with adult disease indicators were not so clear-cut. Increased size at birth and in childhood were positively associated with adult body-mass index and to a lesser extent with blood pressure values, but not with blood glucose concentrations. In our new analyses and in published work, lower birthweight and undernutrition in childhood were risk factors for high glucose concentrations, blood pressure, and harmful lipid profiles once adult body-mass index and height were adjusted for, suggesting that rapid postnatal weight gain--especially after infancy--is linked to these conditions. The review of published works indicates that there is insufficient information about long-term changes in immune function, blood lipids, or osteoporosis indicators. Birthweight is positively associated with lung function and with the incidence of some cancers, and undernutrition could be associated with mental illness. We noted that height-for-age at 2 years was the best predictor of human capital and that undernutrition is associated with lower human capital. We conclude that damage suffered in early life leads to permanent impairment, and might also affect future generations. Its prevention will probably bring about important health, educational, and economic benefits. Chronic diseases are especially common in undernourished children who experience rapid weight gain after infancy.

Fetal, childhood, and adolescence interventions leading to adult disease prevention

Lifestyle choices result in the development and increased severity of many adult diseases that can cause death (eg, heart disease, stroke, cancer, obesity). Most health-damaging behaviors are learned during childhood and adolescence, making that time period a critical window of opportunity to teach health-promoting behaviors. Primary care physicians can implement their overall commitment to providing comprehensive health care to patients and their families by following the anticipatory guidelines of their discipline (eg, pediatrics, family and internal medicine) and by educating patients and their families about the recommendations included on the Web sites of the Centers for Disease Control and Prevention Office of Women's Health and Office of Strategy and Innovation.

Fetal nutrition and adult hypertension, diabetes, obesity, and coronary artery disease

The fetal-origins-of-adult-disease hypothesis describes an adaptive phenomenon of in utero reprogramming of the undernourished fetus that predisposes the infant to increased morbidity as an adult. Studies have identified a positive association between indicators of fetal undernutrition such as low birth weight and chronic adult diseases like hypertension, diabetes, obesity, and coronary artery disease. Current research is focusing on determining other factors that may contribute to these chronic adult diseases.

Association of growth in utero with cognitive function at age 6-8 years

BACKGROUND

Size at birth is associated with later cognitive development. The timing of growth faltering in utero may affect developmental consequences.

AIM

To determine whether growth in utero is related to cognitive outcomes in childhood. A secondary aim was to determine any associations between maternal nutritional status and cognition.

STUDY DESIGN AND SUBJECTS

Subjects were participants in a prospective cohort study of developmental origins of adult disease. Eligible subjects were aged 6-8 years at their next scheduled visit to the study clinic and their mothers had abdominal ultrasound measurements at 14, 25 and 35 weeks gestation. 186 of 264 eligible children attended the clinic and were tested.

OUTCOME MEASURES

Raven's Progressive Matrices (reasoning ability), Peabody Picture Vocabulary Test (receptive vocabulary) and Digit Span Forwards (auditory working memory).

RESULTS

In multiple regression analyses controlling for children's age and socioeconomic status, head circumference at 14 weeks gestation was significantly associated with reasoning ability. The difference between the lowest and highest quartiles was equivalent to 0.4 S.D. No other significant associations with fetal growth were found. Maternal weight gain was not associated with cognitive scores; however, change in triceps skinfold between 25 and 35 weeks gestation was positively associated with reasoning ability and remained a significant predictor when included in the regression model.

CONCLUSIONS

There were few associations between growth in utero and cognition. Growth in head circumference in early gestation and maternal nutrition in late gestation may affect later cognitive ability. Further research in this area is needed to confirm these results.

Developmental programming of cardiovascular disorders: focus on hypertension

Increasing evidence suggests that adult cardiovascular disorders, e.g. hypertension, can be "programmed" in utero. The mechanisms that affect the developing fetus and lead to future cardiovascular disease are not fully established. This review addresses the possible involvement of maternal nutrition, sex steroids and other endocrine factors in the programming of hypertension in adulthood. Some possible mechanisms of subsequent development of hypertension in adulthood, such as elevated sympathetic and renin-angiotensin system activity, and failure of nephron development, also are discussed. Previous studies suggest that maternal undernutrition could be a major factor in fetal programming, but in light of the increased worldwide prevalence of obesity, maternal overnutrition is now receiving increased attention. Special emphasis is given here to this phenomenon. Obesity is associated with increased serum and tissue levels of proinflammatory cytokines, and loss of sensitivity to the adipokine leptin. It is postulated that this causes dysregulation of the hypothalamo-pituitary-adrenal axis, resulting in increased levels of circulating glucocorticoids. These factors could play a major role in programming, during the in utero period, of future hypertension in the offspring of obese mothers.

Cross-sectional study of weight gain and increase in BMI throughout pregnancy

OBJECTIVE

To generate reliable new reference ranges for weight gain and increase in body mass index (BMI) during pregnancy from a large population.

STUDY DESIGN

In a prospective cross-sectional study at the Obstetric outpatient clinic, Zurich University Hospital, weight gain and BMI, before gestation and at the booking visit, were determined in 4034 pregnant women with accurately dateable singleton pregnancies (Caucasian: N = 3242, Asian (predominantly from Sri Lanka, Thailand and the Philippines): N = 578 and Black: N = 214). Women with known insulin-dependent diabetes mellitus before pregnancy were excluded. Fifth, 50th and 95th centiles were presented for Caucasians and corresponding centile curves for Asians and Blacks. Simple and multiple regression analyses were performed for various risk factors. A significance level of P < 0.05 was used in all tests.

RESULTS

Mean weight gain was 15.5+/-5.9 kg (34.2+/-13.0 lb) at term with values >25.4 kg (56.0 lb) and <5.7 kg (12.6 lb) for the 95th and the 5th centile, respectively. Mean BMI increased slightly and steadily to 28 kgm(-2) at term. Parity and pre-pregnancy BMI were significant determinants in Caucasians. Weight gain and BMI was slightly lower in Asians and Blacks.

CONCLUSIONS

BMI centile curves have the advantage in that they consider height during the whole course of pregnancy. It may be an additional helpful tool in controlling weight gain in pregnancy. Further studies are required to determine the prognostic implications of values > or = 95th centile and < or = 5th centile.

What is the effect of adjusting for more than one measure of current body size on the relation between birthweight and blood pressure?

The statistical validity of the negative associations observed between birthweight and disease in later life has recently been questioned, because these associations might be due, in part, to inappropriate adjustment for current body size, creating a statistical artefact known as the 'reversal paradox'. The aim of this study was to explore the effect of adjusting for more than one measure of current body size on the association between birthweight and disease in later life using simulations and meta-analyses of empirical studies. The simulations examined the relation between birthweight and adult systolic blood pressure before and after adjusting for one, two or three measures of current body size by including current weight and subsequently adding body mass index and height in successive analytical models. Meta-analyses were then performed to compare the effect sizes observed among empirical studies reporting associations between birthweight and blood pressure before and after adjusting for one or two measures of current body size. The meta-analyses confirmed the results of the simulations - both showed that associations between birthweight and blood pressure tend to become increasingly negative following adjustment for current body size, and that this effect is enhanced after adjusting for additional measures of current body size.

Hypotheses on the Fetal Origins of Adult Diseases: Contributions of Epidemiological Studies

Epidemiological studies have demonstrated associations between low birth weight and cardiovascular disease, type 2 diabetes and their risk factors in adult life. These findings have led to sharp debates in the literature concerning potential methodological study flaws and the effect size and causality of the associations. More recent studies seem to have overcome most methodological flaws and suggest a small effect size of low birth weight on adult diseases for the individual. However, the effect size may still be important on a population level. Various causal pathways have been hypothesized as mechanisms underlying these associations. These hypotheses have proposed central roles for (1) fetal undernutrition, (2) increased cortisol exposure, (3) genetic susceptibility and (4) accelerated post-natal growth. These hypotheses have been studied in various epidemiological study designs. Thus far, it is still not known which mechanisms underlie the associations between low birth weight and diseases in adult life. The causal pathways linking low birth weight to diseases in later life seem to be complex and may include combined environmental and genetic mechanisms in various periods of life. Well-designed epidemiological studies are necessary to estimate the population effect size and to identify the underlying mechanisms. This knowledge is needed to develop strategies for identifying groups at risk and prevention focused on early life.

Developmental determinants of blood pressure in adults

Over the past 20 years a large and varied body of research has attempted to make the case for the developmental origins of elevated adult blood pressure (BP). Experimental animal research has identified plausible biological mechanisms through which fetal nutritional insufficiency may affect adult BP. The majority of human epidemiologic studies demonstrate an inverse association of birth weight (the most commonly used marker of fetal nutrition) with adult BP and higher risk of hypertension among individuals with lower weight at birth. The most adverse BP outcomes occur among individuals who were small at birth but relatively large as adults, a finding that suggests a role for postnatal growth. We critically review the literature on proposed mechanisms and epidemiologic evidence for developmental origins of adult BP and hypertension, considering associations with birth weight, maternal nutrition during pregnancy, child growth patterns, and infant feeding.

Maternal body composition, offspring blood pressure and the hypothalamic-pituitary-adrenal axis

We tested the hypothesis that women who are thin or have poor pregnancy weight gain have offspring with higher blood pressure and examined whether this link is mediated by increased secretion of cortisol. We studied a cohort of 388 children born in Kingston, Jamaica. From hospital records we obtained information about their mother's body mass index (BMI) and weight gain during pregnancy. At age 8.5 years we measured the children's fasting plasma cortisol concentrations and blood pressure and assessed their mother's anthropometry. There were no relationships between the mother's BMI or weight gain during pregnancy and offspring blood pressure. However, mothers with a greater subscapular to triceps skinfold thickness ratio (SSTR) had offspring with higher blood pressure (5.6 mmHg systolic and 3.7 mmHg diastolic increase per unit change in SSTR, P = 0.002 and P = 0.008 respectively). Fasting plasma cortisol concentrations correlated with the children's systolic (r = 0.33, P < 0.0001) and diastolic pressures (r = 0.12, P = 0.02) independently of age, gender, weight or socio-economic status and were also predicted by the mother's SSTR. These findings suggest that maternal truncal obesity rather than thinness is associated with raised blood pressure in the offspring, and that this link may be mediated by increased cortisol secretion.

Nutrition in multiple gestations

Multiple pregnancies represent a state of magnified nutritional requirements, resulting in a greater nutrient drain on maternal resources and an accelerated depletion of nutritional reserves. Maternal weight gain to 20 weeks and between 20 and 28 weeks has the greatest effect on birthweight in twin and triplet pregnancies, particularly among underweight women. Parity, which most likely represents a higher proportion of body fat, has a positive effect on pregnancy outcome, with an average 7 to 10 days longer gestation for multiparous versus nulliparous women. In addition to being the nutrients most often lacking in a woman's diet, calcium, magnesium, and zinc have been identified as having the most potential for reducing pregnancy complications and improving outcomes.

Prepregnancy body mass index as an important predictor of perinatal outcomes in Japanese

OBJECTIVE

The influence of maternal body mass index (BMI) before pregnancy and weight gain during pregnancy on perinatal outcomes in the Japanese population remains to be elucidated. Therefore, we estimated the risk of perinatal morbidity of the mother and infant with respect to maternal prepregnancy BMI and weight gain during pregnancy in Japanese.

RESULTS

In the obese before pregnancy group, the risks of cesarean delivery, preeclampsia, and gestational diabetes were significantly elevated compared with the normal group. In the underweight before pregnancy group, the risks of low birth weight infant and hospitalization of infant were elevated significantly.

CONCLUSION

However, weight gain during pregnancy did not show any significant influence on the perinatal outcomes of the mother or infant.

Maternal and child nutritional supplementation are inversely associated with fasting plasma glucose concentration in young Guatemalan adults

Cardiovascular disease and diabetes may be programmed early in life by abnormal development associated with undernutrition. We investigated whether maternal nutritional status (MNS; height, pregnancy weight gain, nonpregnant BMI, and prenatal supplementation) or childhood nutritional status (CNS; birth weight, length, ponderal index, height-for-age Z-score at 24 mo, and supplementation from 0 to 24 mo) were related to fasting plasma glucose levels in rural-born Guatemalan adults. We studied 209 men and 220 women (mean age 24.4 y) who were involved in a randomized trial of nutritional supplementation of their mothers during pregnancy and during their early childhoods, conducted from 1969 to 1977. In 2 villages, residents were offered Atole (3.8 MJ and 64 g protein/L); 2 other villages were offered Fresco (1.4 MJ/L, no protein). No associations were observed between anthropometric measures of MNS or CNS and fasting plasma glucose levels. In subgroup analyses, inverse associations (all P < 0.15) with birth size were found among women born to fatter mothers, women with low supplement intake, men born to short mothers, and men more severely stunted at 24 mo. Prenatal supplementation was inversely associated with fasting plasma glucose among women [-0.40 +/- 0.17 mmol/(L. MJ. d), P = 0.02]. Among men, postnatal intake of supplementation of 0.10 to 0.20 MJ/d was associated with up to a 0.56 mmol/L reduction in fasting plasma glucose (P = 0.03), but intake in excess of 0.20 MJ/d provided no added benefit. Among women, the benefit of postnatal supplementation was restricted to those born thin (test for interaction P = 0.10). Improving the nutritional status of undernourished women and children may have positive long-term consequences.

Do variations in blood pressures of South Asian, African and Chinese descent children reflect those of the adult populations in the UK? A review of cross-sectional data

The objective of this study was to assess whether variations in BP in children of UK ethnic minority populations correspond to those seen in adults. A systematic literature review was carried out using MEDLINE 1966-2003 and EMBASE 1980-2003, supplemented by correspondence with expert informants, and citations from references. Five studies were identified. There were important differences between studies in terms of age and sex of samples, definition of ethnic minority children and methods of evaluating BP. Three studies of children of African descent reported lower mean SBP in boys from African descent compared to white boys, the differences being significant only in one study. In African descent girls, the mean SBP was significantly lower in one study, while DBP was significantly higher in one study. Four studies included children of South Asian origin. The Health Survey for England '99 reported on South Asian groups separately. Pakistani boys had a significantly higher age- and height-standardised mean SBP than the general population. The mean DBP was significantly higher in Indian and Pakistani boys than the general population. Pakistani and Bangladeshi girls had a significantly higher mean DBP than the general population. The other three studies, which combined South Asian subgroups found no significant differences in the mean BP between South Asians and white subjects. One study included children of Chinese descent and reported significantly higher mean DBP in Chinese boys and girls compared to the general population. Overall, BP across ethnic groups was similar. These similarities in BP patterns particularly in African, Bangladeshi and Pakistani descent children contrasts with those in the corresponding adult populations in the UK where BP is comparatively high in those of African descent and comparatively low in those of Bangladeshi and Pakistani descent.

Nutritional assessment and support during pregnancy

This article thoroughly updates the authors' previous review of nutritional assessment and support during pregnancy. After briefly reviewing nutrient metabolism and requirements, the authors discuss the nutritional assessment of the pregnant woman and review the nutritional support principles in hyperemesis gravidarum and other conditions that can compromise the nutritional health of mother or fetus.

Publication bias and heterogeneity in the relationship between systolic blood pressure, birth weight, and catch-up growth--a meta analysis

OBJECTIVE

To use meta-analytic techniques to formally examine (1) publication bias, and (2) between-study heterogeneity in the reported regression coefficient of systolic blood pressure (SBP) on birth weight, adjusting for current weight.

DATA IDENTIFICATION

A total of 55 separate analyses reporting on 382 514 male and female subjects ranging from 0 to 75 years, summarized in a recent systematic review.

RESULTS

Some 52 of 55 analyses reported a negative regression coefficient (beta) of SBP on birth weight, adjusting for current size, and in 27 of 55 (49%) the 95% confidence interval (CI) did not include zero. A pooled estimate of the regression coefficient across studies under a random-effects model was -1.38 mmHg/kg (95% CI: -1.66 to -1.10). The magnitude of the regression coefficient was negatively correlated with the age of the study population (r = -0.44, P = 0.0007). However, there was strong evidence of publication bias with smaller studies tending to report more negative betas - the Pearson correlation between beta and its standard error (SE(beta)) was -0.55 (P < 0.0001). To examine independent effects, meta analysis regressions of beta on age and SE(beta) were run. After controlling for age, there remained strong evidence of publication bias (P = 0.002), whereas after controlling for publication bias as measured by SE(beta), the relationship between beta and age was not significant (P = 0.08).

CONCLUSIONS

This analysis strongly suggests, but does not prove, that publication bias is present when systematically examining the relationship between blood pressure and birth weight. Controlling for publication bias lessens the apparent relationship between the regression coefficient and age of the study population.

Anti-hypertensive drugs in pregnancy and fetal growth: evidence for "pharmacological programming" in the first trimester?

OBJECTIVES

To determine the timing and exact nature of the effect of the drug atenolol upon fetal growth. Also to discover if the reduction in fetal growth is due to superimposed pre-eclampsia or any other confounding variable.

DESIGN

A retrospective cohort study of prospectively collected data in a hypertensive pregnancy database.

SETTING

Two district general hospitals in the midlands of England. Both hospitals have specialised medical antenatal clinics for pregnant women with chronic hypertension.

PARTICIPANTS

491 pregnancies in 380 women with essential or secondary hypertension.

OUTCOME MEASURES

The outcome measures used were the infant birth weight, birth weight standardized for gestational age, and the ponderal index at birth, a surrogate measure for in utero growth restriction.

RESULTS

The babies of women taking atenolol at conception or during the first trimester had significantly lower birth weights (by 139-512 g, p<0.01) than women on calcium channel blockers or no medication. Likewise the ponderal index was also significantly reduced, p<0.01. In addition most of these babies were small for gestational age (SGA) with 70% on or below the 10th centile and 40% below the third centile. No such independent association was seen with anti-hypertensives taken in the second trimester.

CONCLUSIONS

Atenolol taken at the time of conception and/or during the first trimester of pregnancy was associated with low birth weight. This finding was independent of the development of superimposed pre-eclampsia. Other anti-hypertensives were not found to be associated with low birth weight. Use of atenolol in the second trimester of pregnancy did not produce the same effect and was not materially different in its effects from the other anti-hypertensive drugs. In the second trimester, the development of superimposed pre-eclampsia is the over-riding effect in the reduction of infant birth weight. Atenolol used in the first trimester could be pharmacologically programming these infants to restricted growth patterns.

The role of the placenta in fetal programming-a review

The fetal origins hypothesis proposes that adult cardiovascular and metabolic disease originate through developmental plasticity and fetal adaptations arising from failure of the materno-placental supply of nutrients to match fetal requirements. The hypothesis is supported by experimental data in animals indicating that maternal nutrition can programme long term effects on the offspring without necessarily affecting size at birth. There is now evidence linking body composition in pregnant women and the balance of nutrient intake during pregnancy with raised levels of cardiovascular risk factors in the offspring. Maternal body composition and diet are thought to affect fetal development and programming as a result of both direct effects on substrate availability to the fetus and indirectly through changes in placental function and structure. Alterations in placental growth and vascular resistance, altered nutrient and hormone metabolism in the placenta, and changes in nutrient transfer and partitioning between mother, placenta and fetus all have important effects on the fetal adaptations thought to be central to programming. Future interventions to improve placental function are likely to have lifelong health benefits for the offspring.

High-meat, low-carbohydrate diet in pregnancy: relation to adult blood pressure in the offspring

To examine the hypothesis that a high-animal protein, low-carbohydrate diet in pregnancy is associated with raised blood pressure in the adult offspring, we performed a follow-up study of 626 men and women in Motherwell, Scotland, whose mothers' food intake had been recorded during pregnancy. The mothers had taken part in a dietary intervention in which they were advised to eat 1 lb (0.45 kg) of red meat per day and to avoid carbohydrate-rich foods during pregnancy. The offspring were followed up at age 27 to 30 years, and their systolic and diastolic blood pressures were measured. Women who reported greater consumption of meat and fish in the second half of pregnancy had offspring with higher systolic blood pressure in adult life (regression coefficient, 0.19 mm Hg per portion per week; 95% confidence interval, 0.04 to 0.35; P=0.02). High maternal consumption of fish, but not meat, was associated with higher diastolic blood pressure in the offspring (regression coefficient, 1.00 mm Hg per portion per week; 95% confidence interval, 0.18 to 1.82; P=0.02). These associations were independent of maternal blood pressure, body size, and smoking habits during pregnancy. Although we cannot exclude confounding by maternal saturated fat or salt intake, the findings support those of a study in Aberdeen showing higher blood pressure in men and women whose mothers had eaten a high-animal protein, low-carbohydrate diet in late pregnancy. These associations may reflect the metabolic stress imposed on the mother by an unbalanced diet in which high intakes of essential amino acids are not accompanied by the nutrients required to utilize them.

Maternal energy stores and diet composition during pregnancy program adolescent blood pressure

BACKGROUND

Fetal undernutrition is hypothesized to program blood pressure (BP) later in life. Human epidemiological studies that use birth weight as a proxy for fetal malnutrition fail to identify specific aspects of maternal nutrition responsible for programming.

METHODS AND RESULTS

We examined how maternal nutrition during pregnancy and infant birth weight relate to systolic and diastolic BP (SBP and DBP) in 2026 Filipino adolescents. Data were collected prospectively during the Cebu (Philippines) Longitudinal Health and Nutrition Survey. Women were assessed at approximately 30 weeks gestation, and children were followed from birth through adolescence. Regression models were used to examine how the mothers' total energy intake, percentage of energy from protein and fat, triceps skinfold thickness during pregnancy, and infant birth weight relate to adolescent BP, controlling for current age, height, and body mass index and other potential confounders. Maternal triceps skinfold thickness was significantly inversely related to SBP among boys and to DBP in boys and girls. Maternal nutrition variables attenuated but did not eliminate an inverse birth weight-SBP relationship in boys. SBP was significantly inversely related to the mothers' percent of dietary energy from protein in boys. Among girls, SBP and DBP were inversely related to the mothers' percentage of calories from fat. There was no evidence of confounding of these relationships by current diet, maturation status, physical activity, or socioeconomic status.

CONCLUSIONS

Maternal diet composition and energy stores in the form of subcutaneous fat have long-term effects on offspring BP in adolescence.

Fetal programming and adult health

Low birthweight is now known to be associated with increased rates of coronary heart disease and the related disorders stroke, hypertension and non-insulin dependent diabetes. These associations have been extensively replicated in studies in different countries and are not the result of confounding variables. They extend across the normal range of birthweight and depend on lower birthweights in relation to the duration of gestation rather than the effects of premature birth. The associations are thought to be consequences of 'programming', whereby a stimulus or insult at a critical, sensitive period of early life has permanent effects on structure, physiology and metabolism. Programming of the fetus may result from adaptations invoked when the materno-placental nutrient supply fails to match the fetal nutrient demand. Although the influences that impair fetal development and programme adult cardiovascular disease remain to be defined, there are strong pointers to the importance of maternal body composition and dietary balance during pregnancy.

The role of size at birth and postnatal catch-up growth in determining systolic blood pressure: a systematic review of the literature

OBJECTIVE

To conduct a systematic review in order to (i) summarize the relationship between birthweight and blood pressure, following numerous publications in the last 3 years, (ii) assess whether other measures of size at birth are related to blood pressure, and (iii) study the role of postnatal catch-up growth in predicting blood pressure.

DATA IDENTIFICATION

All papers published between March 1996 and March 2000 that examined the relationship between birth weight and systolic blood pressure were identified and combined with the papers examined in a previous review.

SUBJECTS

More than 444,000 male and female subjects aged 0-84 years of all ages and races.

RESULTS

Eighty studies described the relationship of blood pressure with birth weight The majority of the studies in children, adolescents and adults reported that blood pressure fell with increasing birth weight, the size of the effect being approximately 2 mmHg/kg. Head circumference was the only other birth measurement to be most consistently associated with blood pressure, the magnitude of the association being a decrease in blood pressure by approximately 0.5 mmHg/cm. Skeletal and non-skeletal postnatal catch-up growth were positively associated with blood pressure, with the highest blood pressures occurring in individuals of low birth weight but high rates of growth subsequently.

CONCLUSIONS

Both birth weight and head circumference at birth are inversely related to systolic blood pressure. The relationship is present in adolescence but attenuated compared to both the pre- and post-adolescence periods. Accelerated postnatal growth is also associated with raised blood pressure.

Fetal nutrition and adult disease

Recent research suggests that several of the major diseases of later life, including coronary heart disease, hypertension, and type 2 diabetes, originate in impaired intrauterine growth and development. These diseases may be consequences of "programming," whereby a stimulus or insult at a critical, sensitive period of early life has permanent effects on structure, physiology, and metabolism. Evidence that coronary heart disease, hypertension, and diabetes are programmed came from longitudinal studies of 25,000 UK men and women in which size at birth was related to the occurrence of the disease in middle age. People who were small or disproportionate (thin or short) at birth had high rates of coronary heart disease, high blood pressure, high cholesterol concentrations, and abnormal glucose-insulin metabolism. These relations were independent of the length of gestation, suggesting that cardiovascular disease is linked to fetal growth restriction rather than to premature birth. Replication of the UK findings has led to wide acceptance that low rates of fetal growth are associated with cardiovascular disease in later life. Impaired growth and development in utero seem to be widespread in the population, affecting many babies whose birth weights are within the normal range. Although the influences that impair fetal development and program adult cardiovascular disease remain to be defined, there are strong pointers to the importance of the fetal adaptations invoked when the maternoplacental nutrient supply fails to match the fetal nutrient demand.

Effects of infant birthweight and maternal body mass index in pregnancy on components of the insulin resistance syndrome in China

BACKGROUND

Reduced birthweight is associated with increased risk for the insulin resistance syndrome. Part of this risk is hypothesized to originate from undernutrition in utero. The prevalence of the insulin resistance syndrome increases in countries that undergo the transition from chronic malnutrition to adequate nutrition, when postnatal nutrition improves more rapidly than prenatal nutrition.

OBJECTIVE

To determine whether the components of the insulin resistance syndrome are associated with reduced fetal growth and maternal undernutrition.

DESIGN

A nonconcurrent, prospective study of men and women whose mothers' heights and weights were recorded during pregnancy.

SETTING

Beijing, China.

PARTICIPANTS

627 men and women (mean age, 45 years) whose mothers' obstetric records were preserved.

MEASUREMENTS

Adult offspring's blood pressure, plasma glucose levels, insulin levels, and lipid concentrations during an oral glucose tolerance test. The main explanatory measurements were mothers' body mass index during pregnancy and offspring's birthweight and adult size.

RESULTS

After adjustment for sex and current body mass index, low birthweight was associated with elevated plasma glucose levels, insulin levels, triglyceride concentrations, and blood pressure. For every 1-kg increase in birthweight, systolic blood pressure decreased by 2.9 mm Hg (95% CI, 0.3 to 5.4 mm Hg) and the 2-hour plasma glucose level decreased by 5.1% (CI, 0.7% to 9.3%). Low maternal body mass index in early and late pregnancy was associated with elevated levels of plasma glucose, insulin, and triglycerides in adult offspring but was not associated with elevated blood pressure.

CONCLUSIONS

Risk for the insulin resistance syndrome may be partially established through low maternal body mass before pregnancy and consequent fetal undernutrition. This risk is independent of that associated with adult obesity. In developing countries such as China, improved nutrition in girls and young women may offer long-term benefits to offspring.

In utero programming of cardiovascular disease

Low birth weight, thinness and short body length at birth are now known to be associated with increased rates of cardiovascular disease and non-insulin dependent diabetes in adult life. The fetal origins hypothesis proposes that these diseases originate through adaptations which the fetus makes when it is undernourished. These adaptations may be cardiovascular, metabolic or endocrine. They permanently change the structure and function of the body. Prevention of the diseases may depend on prevention of imbalances in fetal growth or imbalances between pre- and post-natal growth, or imbalances in nutrient supply to the fetus.

Effect of intrauterine growth restriction on blood pressure, glucose tolerance and sympathetic nervous system activity in the rat at 3-4 months of age

OBJECTIVE

Epidemiological studies suggest that intrauterine growth restriction (IUGR) due to maternal undernutrition during pregnancy represents a major risk factor for hypertension and diabetes in adult age. However, placental insufficiency, rather than maternal malnutrition, is the main cause of IUGR in the Western world. We therefore studied the relationship between birth weight and adult blood pressure and glucose tolerance in an established animal model of placental insufficiency.

DESIGN

IUGR was induced by uterine artery ligation in pregnant rats and the offspring were studied at 3-4 months of age.

METHODS

In one subgroup of animals (n = 41, birth weight range 3.2-6.6 g) blood pressure was recorded over 72 h using telemetry and hypothalamic tissue levels of noradrenaline was measured. In another subgroup (n = 30, birth weight range 3.0-6.8 g) the activity of the sympathetic nervous system (SNS) was assessed by noradrenaline isotope dilution techniques and glucose tolerance determined by an intravenous glucose load.

RESULTS

Adult blood pressure was independent of birth weight Haemodynamic responses of IUGR rats to moderate sound stress was unaltered. In male rats neither SNS activity, hypothalamic noradrenaline concentrations nor glucose tolerance was associated with birth weight In contrast, IUGR in female rats was associated with increased SNS activity, elevated fasting blood glucose as well as lower insulin and higher glucose levels in response to a glucose load.

CONCLUSION

IUGR is not linked to an elevated blood pressure at 3-4 months of age in this model. However, in female rats, IUGR is associated with increased SNS activity and impaired glucose tolerance in adult life.

Blood pressure in adults after prenatal exposure to famine

BACKGROUND

Many studies have shown that low birth weight is associated with high blood pressure. The composition of the diet of pregnant women has also been found to affect blood pressure in their children. We assessed the effect of prenatal exposure to the Dutch famine of 1944-1945, during which the caloric intake from protein, fat and carbohydrate was proportionally reduced, on blood pressures in adults now aged about 50 years.

METHODS AND RESULTS

We measured blood pressures at home and in the clinic among people born at term in one hospital in Amsterdam, The Netherlands, between November 1 1943 and February 28 1947, for whom we had detailed birth records. Blood pressures of people exposed to famine during late (n = 120), mid-(n = 109) or early gestation (n = 68) were compared with those of people born in the year before or conceived in the year after the famine (unexposed subjects, n = 442). No effect of prenatal exposure on systolic and diastolic blood pressure was observed. The mean systolic blood pressure taken in the clinic in those exposed in late gestation, and adjusted for sex and age, was 1.3 mmHg higher than in the unexposed group (95% confidence interval -1.9 to 4.4). The mean systolic blood pressure differed by -0.6 mmHg (95% confidence interval -3.9 to 2.7) for those exposed in mid-gestation and -1.7 mmHg (95% confidence interval -5.6 to 2.2) for those exposed in early gestation. People who were small at birth had higher blood pressures. A 1 kg increase in birth weight was associated with a decrease of 2.7 mmHg (95% confidence interval 0.3 to 5.1) in systolic blood pressure. Analyses of blood pressures measured at home gave similar results.

CONCLUSION

High blood pressure was not linked to prenatal exposure to a balanced reduction of macronutrients in the maternal diet. However, it was linked to reduced fetal growth. We postulate that it might be the composition rather than the quantity of a pregnant woman's diet that affects her child's blood pressure in later life.

Relationship between birthweight and blood pressure in childhood

Studies have shown an inverse relationship between birthweight and blood pressure in later life. The objective of this study is to analyze the relationship between birthweight and blood pressure in childhood in a North American-based population. Data on 2,958 births with follow-up at 7 years of age from the Providence, RI, cohort of the Collaborative Perinatal Project of the National Institute of Neurological Diseases and Stroke were retrospectively analyzed using univariate and multivariate analytic methods. Bivariate analysis of the total cohort showed a direct relationship between follow-up weight at age 7 years and birthweight (r = 0.24; P < 0.001) and follow-up weight with systolic (SBP) and diastolic blood pressure (DBP; r = 0.33; P < 0.001 and r = 0.22; P < 0.001, respectively). On multivariate analysis, follow-up weight and height were the strongest predictors of SBP and DBP. There was also a significant inverse relationship between birthweight and SBP. A cohort of term infants (n = 2,561) was subdivided into birthweight-for-gestational-age groupings to further evaluate the effects of birthweight on blood pressure. Small-for-gestational-age (SGA) infants were markedly smaller at age 7 years than those large-for-gestational-age (LGA; 21 +/- 4 kg v 26 +/- 4 kg; P < 0.01). Despite the direct association between follow-up weight and blood pressure, the mean blood pressure did not differ between SGA (103/58 mm Hg) and LGA patients (103/59 mm Hg). To assess whether birthweight was an independent predictor of blood pressure, blood pressures were predicted using linear regression equations. For every 1-kg decrease in birthweight in term infants, SBP at 7 years increased by 1.3 mm Hg and DBP by 0.6 mm Hg. In conclusion, controlling for weight and height in term infants at 7 years of age has an inverse linear effect on blood pressure. This suggests that birthweight in relation to gestation may be a contributor to the multifactorial cause of essential hypertension.