Pregnancy complications and maternal risk of ischaemic heart disease: a retrospective cohort study of 129,290 births

Fetal adaptation to stress: Part II. Evolutionary aspects; stress-induced hippocampal damage; long-term effects on behavior; consequences on adult health

Humans share adaptative capacities to stress with other species, as demonstrated on amphibians: the physiological response to experimental water volume and food deprivation results in the activation of the endocrine axes that drive metamorphosis, in particular the neuroendocrine stress system. Unfavorable effects may, however, occur, probably due to inappropriate timing and/or duration of stress: recent experiments are converging to show a profound impairment of hippocampal functioning in the offspring of mothers exposed to prenatal stress. Moreover, fetal changes are likely one of the risk factors for a number of diseases in adulthood.

Parents’ Growth in Childhood and the Birth Weight of Their Offspring

BACKGROUND

A person's birth weight is inversely related to both their own and their parents' cardiovascular disease mortality risk, but mechanisms underlying such transgenerational associations are unclear. We investigated the influence of the childhood growth of the mother or father on the birth weight of their first-born offspring.

METHODS

We used data from the long-term follow up (in 1997-1998) of 4999 children from 1352 families who participated in the Boyd Orr Survey of Diet and Health in Pre-War Britain (1937-1939). Complete information on childhood height, potential confounding variables, and the birth weight of first-born offspring was available for 637 subjects.

RESULTS

Mother's height in childhood was positively associated with her offspring's birth weight. Leg length, but not trunk length, was the component of maternal height associated with offspring birth weight. For each unit increase in z-score for maternal childhood leg length, there was a 96-g (95% confidence interval = 6-186) increase in offspring birth weight after controlling for childhood socioeconomic variables and adult height. There were weaker positive associations of paternal height and leg length in childhood with offspring birth weight. Associations were not confounded by maternal birth weight or midgrandparental height.

CONCLUSIONS

Our findings are consistent with the hypothesis that maternal growth during childhood influences offspring birth weight, independently of maternal birth weight, final attained height, or midgrandparental height. Because leg length is a sensitive marker of adverse nutritional and social exposures during childhood, these results suggest a key role for a mother's early environmental exposures as a determinant of her child's subsequent health.

Manifestations of Metabolic Syndrome After Hypertensive Pregnancy

Small follow-up studies of hospital-based series indicate women with preeclampsia have an increased risk of insulin resistance postpartum. However, long-term data are lacking among women with gestational hypertension without proteinuria. Using a general population-based sample of 5889 women from Northern Finland followed longitudinally since birth in 1966, we examined these associations and the influence of the subject’s own birth weight and gestational age on this relationship. At age 31, blood pressure was measured and blood samples collected from 2678 women, of which 1463 women had had at least 1 singleton pregnancy. Of these, 45 had been hospitalized because of gestational hypertension and 49 because of preeclampsia. Women who had had either gestational hypertension or preeclampsia during their first pregnancy (average age 25 years) had increased blood pressure at 31 years compared with women with previous normotensive pregnancy, even after adjustment for body mass index ( P <0.001 in gestational hypertension, P =0.023 in preeclampsia group). When compared with the whole female population, women with previous gestational hypertension at same age still had higher blood pressure, while this difference was weaker for women with previous preeclampsia. Women with gestational hypertension and preeclampsia also had higher waist circumference, waist/hip ratio, and body mass index, as well as increased serum insulin levels and lower glucose/insulin ratio than women with previous normotensive pregnancy. The associations remained after adjustment for participant’s own birth weight or gestational age. Women born before gestational week 37 had a 2-fold risk for gestational hypertension in their first pregnancy (RR: 2.53; 95% CI: 1.0, 6.2).

First trimester origins of fetal growth impairment

The timing of factors that lead to disorders of fetal growth have been studied for many years. Previous studies have focused on disorders of the "second wave" of trophoblast invasion of myometrial arterioles and on fetal weight gain in the third trimester. Over the last 5 years, clinical studies have shown associations between first trimester ultrasound and biochemical parameters and the risk of later adverse perinatal outcome. First trimester growth restriction is associated with an increased risk of low birth weight, low birth weight percentile for gestational age and extremely preterm birth. This may reflect a defect in early pregnancy placentation and later adverse outcome. Consistent with this hypothesis, low first trimester circulating maternal concentrations of pregnancy-associated plasma protein A, a trophoblast-derived regulator of the insulin-like growth factor system, are associated with an increased risk of later stillbirth, growth restriction, pre-term birth and pre-eclampsia. Even among healthy women having normal pregnancies, first trimester circulating concentrations of pregnancy-associated plasma protein A correlate with the timing of spontaneous labor and the eventual birth weight. These analyses suggest that in some women complications of late pregnancy have their origins in the very earliest weeks of gestation and precede first attendance for prenatal care.

How the endothelium and its bone marrow-derived progenitors influence development of disease

The association between diseases accompanied by abnormal endothelial/vascular function (atherosclerosis, hypertension, diabetes mellitus, preeclampsia), and conditions characterized by increased tissue growth and normal endothelial/vascular function (cancer, placental size, birth length, adult height) could be caused by inherited characteristics of endothelial cells and their bone marrow-derived precursors. The genotype responsible for normal endothelial/precursor function could be modified by intrauterine and postnatal endothelial injury; telomere shortening caused by increased endothelial precursor proliferation in response to injury can result in premature endothelial senescence and a decreased precursor proliferative potential, thereby leading to an abnormal endothelial/precursor phenotype and the associated diseases. The individual endothelial/precursor phenotype could be established early in life and its changes in response to risk factors for diseases followed over time, thus providing a unique opportunity for identification and early institution of prophylactic and therapeutic interventions in diseases that cause most of the morbidity and mortality in advanced industrialized societies.

Subclassification of preeclampsia

Preeclampsia is a heterogeneous disorder, and as with other diseases (e.g., type I and type II diabetes), progress in the understanding of this disorder would be assisted greatly if subtypes could be characterized. We suggest that a first step would be to subdivide preeclampsia into early-onset disease (< 34 + 0 weeks') and late onset disease (> 34 + 0 weeks').

Cardiovascular and thromboembolic events following hypertensive pregnancy

BACKGROUND

Hypertension is a common complication of pregnancy. Previous evidence has linked pregnancy-related hypertension to maternal cardiovascular disease. We conducted a population-based cohort study to estimate the risks for cardiovascular and thromboembolic events in women with pregnancy-related hypertension.

METHODS

We analyzed data from all singleton births recorded in Washington State from 1987 to 1998. Mothers were classified as having gestational hypertension, preeclampsia, or chronic hypertension based on hospital discharge and birth record information. Birth records were linked to subsequent hospitalizations within Washington State. Proportional hazards models were used to estimate the relationship between each form of pregnancy-related hypertension and subsequent risk for cardiovascular and thromboembolic events.

RESULTS

We identified 31,239 eligible hypertensive pregnancies from 807,010 births. During follow-up, there were 118 hospitalizations for a first acute cardiovascular event and 172 hospitalizations for a first thromboembolic event. Gestational hypertension, mild preeclampsia, and severe preeclampsia were associated with 2.8-fold (95% confidence interval [CI], 1.6 to 4.8), 2.2-fold (95% CI, 1.3 to 3.6), and 3.3-fold (95% CI, 1.7 to 6.5) greater risks for cardiovascular events, respectively. Severe preeclampsia was associated with a 2.3-fold (95% CI, 1.3 to 4.2) greater risk for thromboembolic events.

CONCLUSION

Preeclampsia and gestational hypertension are associated with increased risk for cardiovascular events. Pregnancy-induced hypertension appears to be an important risk factor for the development of future cardiovascular disease in young women.

Elevated plasma homocysteine in early pregnancy: a risk factor for the development of nonsevere preeclampsia

OBJECTIVE

We have recently demonstrated that an elevated plasma homocysteine in early pregnancy is associated with the development of severe preeclampsia. The aim of this study was to determine whether an elevated plasma homocysteine in early pregnancy is also associated with the development of nonsevere preeclampsia.

STUDY DESIGN

Blood was obtained from patients attending for a first antenatal visit. Subjects were asymptomatic women who subsequently developed nonsevere preeclampsia. Controls were matched for parity, gestational age, and date of sample collection. Plasma homocysteine was measured using fluorescence polarization immunoassay.

RESULTS

There were 71 cases of nonsevere preeclampsia sampled at a mean gestational age (+/-SD) of 15.9+/-3.6 weeks and 142 controls at 15.6+/-3.4 weeks. The preeclampsia cases had a mean (+/-SD) homocysteine level of 8.4+/-2.4 micromol/L, whereas controls had a mean homocysteine of 7.07+/-1.5 micromol/L (P</=.0001).

CONCLUSION

Women who develop nonsevere preeclampsia have higher plasma homocysteine levels in early pregnancy compared with women who remain normotensive throughout pregnancy. An elevated plasma homocysteine value in early pregnancy may be associated with a 4-fold increased risk for development of nonsevere preeclampsia.

Hypertensive diseases of pregnancy and risk of hypertension and stroke in later life: results from cohort study

OBJECTIVE

To examine the association between hypertensive diseases of pregnancy (gestational hypertension and pre-eclampsia) and the development of circulatory diseases in later life.

DESIGN

Cohort study of women who had pre-eclampsia during their first singleton pregnancy. Two comparison groups were matched for age and year of delivery, one with gestational hypertension and one with no history of raised blood pressure.

SETTING

Maternity services in the Grampian region of Scotland.

PARTICIPANTS

Women selected from the Aberdeen maternity and neonatal databank who were resident in Aberdeen and who delivered a first, live singleton from 1951 to 1970.

MAIN OUTCOME MEASURES

Current vital and cardiovascular health status ascertained through postal questionnaire survey, clinical examination, linkage to hospital discharge, and mortality data.

RESULTS

There were significant positive associations between pre-eclampsia/eclampsia or gestational hypertension and later hypertension in all measures. The adjusted relative risks varied from 1.13-3.72 for gestational hypertension and 1.40-3.98 for pre-eclampsia or eclampsia. The adjusted incident rate ratio for death from stroke for the pre-eclampsia/eclampsia group was 3.59 (95% confidence interval 1.04 to 12.4).

CONCLUSIONS

Hypertensive diseases of pregnancy seem to be associated in later life with diseases related to hypertension. If greater awareness of this association leads to earlier diagnosis and improved management, there may be scope for reducing a proportion of the morbidity and mortality from such diseases.

Association between leg length and offspring birthweight: partial explanation for the trans-generational association between birthweight and cardiovascular disease: findings from the British Women's Heart and Health Study

Low birthweight individuals not only have increased risk of cardiovascular disease themselves, but cardiovascular disease risk is also increased in their parents. The mechanisms underlying these trans-generational associations are not fully understood. We hypothesise that, in part, they reflect the trans-generational effects of poor maternal environmental circumstances in early childhood. Adverse environmental factors acting early in the mother's life will not only influence her own predisposition to cardiovascular disease but will also result in adverse consequences - low birthweight and increased cardiovascular disease risk in later life - for her offspring. Adult leg length is a valid indicator of early life environmental circumstances, in particular of infant nutrition. If our hypothesis is correct, then adult leg length should be positively associated with offspring birthweight. In this study of 4286 randomly selected women aged 60-79 years from 23 towns across England, Scotland and Wales, the magnitude of the association between leg length and offspring birthweight was greater than the association between trunk length and offspring birthweight. After control for potential confounding factors, offspring birthweight increased by 89.8 g [95% confidence interval 66.1, 113.5 g] for each standard deviation increase in maternal leg length, and by 55.2 g [32.2, 78.1 g] for each standard deviation increase in maternal trunk length. The association between leg length and offspring birthweight was unaffected by adjustment for maternal birthweight, but the association between trunk length and offspring birthweight was attenuated to 38.0 g [1.0, 74.9 g]. These findings support the hypothesis that adverse early childhood environmental circumstances affect not only the vitality and health of the woman in later life but also the birthweight of her offspring, and suggest that the trans-generational association between birthweight and cardiovascular disease is in part explained by early childhood maternal environmental circumstances.

The fetal origins of atherosclerosis: maternal hypercholesterolemia, and cholesterol-lowering or antioxidant treatment during pregnancy influence in utero programming and postnatal susceptibility to atherogenesis

It has long been postulated that pathogenic events during fetal development influence atherosclerosis-related diseases later in life, but the mechanisms involved are unknown. This review focuses on the evidence indicating that maternal hypercholesterolemia during pregnancy is responsible for one cascade of pathogenic events. Maternal hypercholesterolemia is associated with greatly increased fatty streak formation in human fetal arteries and accelerated progression of atherosclerosis during childhood. Recent experiments in genetically more homogeneous rabbits established that temporary diet-induced maternal hypercholesterolemia is sufficient to enhance fetal lesion formation. More important, maternal hypercholesterolemia or ensuing pathogenic events in the fetus increase postnatal atherogenesis in response to hypercholesterolemia. Maternal treatment with cholesterol-lowering agents or antioxidants greatly reduces fetal and postnatal atherogenesis, indicating a pathogenic role of lipid peroxidation and a potential involvement of oxidation-sensitive signaling pathways. Experiments in a murine model showed that differences in arterial gene expression between offspring of normo- and hypercholesterolemic mothers persist long after birth, supporting the assumption that fetal lesion formation is associated with genetic programming, which may in turn affect postnatal atherogenesis. A better understanding of pathogenic programming events in utero may lead to the identification of genes determining the susceptibility to atherosclerosis and define novel preventive approaches.

Birth weight of offspring and insulin resistance in late adulthood: cross sectional survey

OBJECTIVE

To investigate the association between birth weight of offspring and mothers' insulin resistance in late adulthood.

DESIGN

Cross sectional survey.

SETTING

General practitioner's surgeries in 23 towns in Great Britain.

PARTICIPANTS

4286 women aged 60-79 years.

MAIN OUTCOME MEASURES

Maternal insulin resistance.

RESULTS

Birth weight of offspring was inversely related to maternal insulin resistance in late adulthood. For each 1 kg higher birth weight of offspring, women had a 15% reduction in the odds of being in the fourth with highest insulin resistance, compared to other fourths (odds ratio 0.85; 95% confidence interval 0.71 to 1.00). This increased to 27% (0.73; 0.60 to 0.90) after adjusting data for potential confounders. A U shaped relation between birth weight of offspring and diabetes in older age was found; women with the lightest and heaviest offspring had the highest prevalence of diabetes.

CONCLUSIONS

Birth weight of offspring is inversely related to the mother's insulin resistance in late adulthood, despite the association of glucose intolerance during pregnancy with heavier offspring at birth. Common genetic factors contribute to the relation between birth weight and risk of cardiovascular disease and diabetes in adults.

Is type 2 diabetes mellitus a disorder of the brain?

I propose that type 2 diabetes mellitus is due to damage to neurons in the ventromedial hypothalamus or to a defect in the action or properties of insulin or insulin receptors in the brain. These neuronal abnormalities are probably secondary to a marginal deficiency of long-chain polyunsaturated fatty acids during the critical periods of brain growth and development. Hence, supplementation of adequate amounts of long-chain polyunsaturated fatty acids during the third trimester of pregnancy to 2 y postterm can prevent or postpone the development of diabetes mellitus.

Nutritional influences on lipids and future atherosclerosis beginning prenatally and during childhood

Autopsy findings of pre-atherosclerotic changes in the coronaries and other arteries of young soldiers killed in action in the Korean war stimulated studies on the mechanisms that regulate the development of atherosclerosis. The data confirmed that vascular changes obviously begin developing much earlier than the manifestation of clinical symptoms, and numerous risk factors for atherosclerosis have been firmly identified. The mechanisms consist of the effects of numerous poorly characterized genes and a complex mixture of environmental factors, dominated by factors associated with nutrition. Observational and epidemiological studies also showed that the pathogenesis is not restricted to the postnatal period. The nutrition of the fetus during the 40 weeks of pregnancy may also play an important role both directly and by determining metabolism in the individual more widely than was previously believed. At the same time, several studies suggested that biochemical predictors of atherosclerosis, e.g. a high concentration of serum LDL cholesterol, a low concentration of serum HDL cholesterol and other lipid and lipoprotein abnormalities, may already in early infancy and childhood predict values later in life quite well. We now review recent studies that deal with the effects of fetal and childhood nutrition on serum lipid values, and discuss the likelihood that clinically meaningful changes of atherosclerosis may appear earlier than expected.