Vivienne M. Moore

The prevalence of polycystic ovary syndrome in a community sample assessed under contrasting diagnostic criteria

BACKGROUND Polycystic ovary syndrome (PCOS) is considered to be the most common endocrine disorder in women of reproductive age, yet debate over appropriate diagnostic criteria and design limitations with sampling methodology have left some doubt as to the actual prevalence in the community. The objective of this study was to create a representative prevalence estimate of PCOS in the community under the National Institutes of Health (NIH) criteria and the more recent Rotterdam consensus criteria and Androgen Excess Society (AES) criteria. METHODS A retrospective birth cohort study was carried out in which 728 women born during 1973-1975 in a single maternity hospital were traced and interviewed in adulthood (age = 27-34 year; n = 728). Symptoms of PCOS (hyperandrogenism, menstrual dysfunction and polycystic ovaries) were identified by examination and the presence of polycystic ovaries in those that did not consent to the ultrasound were imputed. RESULTS The estimated prevalence of PCOS in this birth cohort using the NIH criteria was 8.7 +/- 2.0% (with no need for imputation). Under the Rotterdam criteria, the prevalence was 11.9 +/- 2.4% which increased to 17.8 +/- 2.8% when imputed data were included. Under the AES recommendations, PCOS prevalence was 10.2 +/- 2.2%, and 12.0 +/- 2.4% with the imputed data. Of the women with PCOS, 68-69% did not have a pre-existing diagnosis. CONCLUSIONS The Rotterdam and AES prevalence estimates were up to twice that obtained with the NIH criteria in this, as well other prevalence studies. In addition, this study also draws attention to the issue of many women with PCOS in the community remaining undiagnosed.

Origins of fetal growth restriction

Regulation of growth of the fetus and its placenta begins before pregnancy. Early in pregnancy the mother sets the rate of growth of the fetus on a trajectory, which may be modified by events later in pregnancy. Low maternal weight for height, history of previous small babies, maternal undernutrition, pregnancy disorders, e.g. pre-eclampsia, are associated with low birthweight. Maternal smoking is a major factor in developed countries; infections and undernutrition in developing countries.Recently, there has been emphasis on adverse long-term outcomes including ischaemic heart disease, hypertension and diabetes associated with poor fetal growth. Experimental studies in animals show that some of these outcomes can readily be induced by restriction of fetal growth. Progress in determining successful treatments to improve the growth of the fetus has lagged behind these epidemiological and experimental findings. However, nutrient supplements improve growth in undernourished women and smoking cessation also improves fetal size and outcome.

Placental weight, birth measurements, and blood pressure at age 8 years.

OBJECTIVE: To examine relationships between blood pressure during childhood and both placental weight and body size at birth, in an Australian population. DESIGN: A follow up study of a birth cohort, undertaken when cohort members were aged 8 years. SETTING: Adelaide, South Australia. SUBJECTS: 830 children born in the Queen Victoria Hospital in Adelaide, South Australia, during 1975-6. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressure measured when the children were aged 8 years. RESULTS: Blood pressure at 8 years was positively related to placental weight and inversely related to birth weight, after adjusting for the childs current weight. For diastolic pressure there was a decrease of 1.0 mm Hg for each 1 kg increase in birth weight (95% confidence interval (CI) = -0.4 to 2.4) and an increase of 0.7 mm Hg for each 100 g increase in placental weight (95% CI = 0.1 to 1.3). Diastolic pressure was also inversely related to chest circumference at birth, independently of placental weight, with a decrease of 0.3 mm Hg for each 1 cm increase in chest circumference (95% CI = 0.2 to 0.5). CONCLUSIONS: These findings are further evidence that birth characteristics, indicative of fetal growth patterns, are related to blood pressure in later life.

The relationship between birth weight and blood pressure amplifies from childhood to adulthood.

OBJECTIVE To investigate relationships between birth characteristics and blood pressure at age 20 years and to assess whether effects of birth weight on blood pressure are amplified from childhood to adulthood. DESIGN A longitudinal study of 584 men and women from Adelaide, Australia, examined previously at 8 years and followed up at age 20 years. RESULTS Birth weight was negatively associated with systolic pressure at age 20 years in men (regression coefficient 2.6 mmHg per kg; 95% confidence interval 0.7, 4.4) and women (regression coefficient 4.6 mmHg per kg; 95% confidence interval 2.9, 6.4), after adjustment for current weight There was an interaction with current size (P = 0.05 for men and P = 0.09 for women), such that effects were enhanced among individuals with relatively high weight or weight for height. Shortness at birth, thinness at birth, and low birth weight relative to placental weight were also associated with elevated systolic pressure at age 20 years. Effects of birth weight on blood pressure were stronger at age 20 than at age 8 years (P < 0.01 for men and P = 0.03 for women). This was not due simply to increased variability of blood pressure in adulthood. There were greater rises in blood pressure with age among individuals of relatively low birth weight. CONCLUSIONS These findings are further evidence that poor fetal growth is associated with elevated blood pressure in later life. The results support the hypothesis that the relationship is amplified with increasing age.

Alcohol consumption and insulin resistance in young adults

Alcohol may have a cardioprotective effect. One possible mechanism is by reducing insulin resistance, a known cardiovascular risk factor. The aim of this study was to assess the relationship between alcohol consumption, insulin resistance and other parameters determining glucose tolerance in 154 young men and women.

Diet around conception and during pregnancy – effects on fetal and neonatal outcomes

Substrate supply to the fetus is a major regulator of prenatal growth. Maternal nutrition influences the availability of nutrients for transfer to the fetus. Animal experiments demonstrate that restriction of maternal protein or energy intake can retard fetal growth. Effects of maternal nutrition vary with the type and timing of the restriction and the species studied. Maternal undernutrition before conception and/or in early pregnancy can alter fetal physiology in late gestation, and influence postnatal function, often without measurable effects on birth size. In contrast, to date, observational and intervention studies in humans provide limited support for a major role of maternal nutrition in determining birth size, except where women are quite malnourished. However, recent studies report associations between newborn size and the balance of macronutrients in womens diets in Western settings. Associations between maternal dietary composition and adult blood pressure of the offspring are also reported in human populations. Most studies in women have focused on dietary content or supplementation during mid-late pregnancy. Further investigation of how maternal dietary composition, before conception and throughout pregnancy, affects fetal physiology and health of the baby will increase the understanding of how maternal diet and nutritional status influence fetal, neonatal and longer-term outcomes.

Diet during pregnancy, neonatal outcomes and later health

Renewed interest in nutrition during pregnancy has been generated by the hypothesis that adult disease has origins in early life. Animal experiments clearly show that altering maternal diet before and during pregnancy can induce permanent changes in the offsprings birth size, adult health and lifespan. Among women living in Western societies, cigarette smoking is the most important factor known to reduce fetal growth, followed by low pre-pregnancy weight and low gestational weight gain. Obesity is also associated with pregnancy complications and adverse neonatal outcomes, so inadequate or excessive energy intake is not optimal for the developing fetus. Against a history of inconsistent results, several recent studies suggest that in Western settings the balance of macronutrients in a womans diet can influence newborn size. Effects appear to be modest, but this relationship may not encapsulate the full significance for health of the child, as there is emerging evidence of associations with long-term metabolic functioning that are independent of birth size. Consequences of inadequate maternal nutrition, for the offspring, may depend on timing during gestation, reflecting critical windows for fetal development. Where women are not malnourished, changing a womans nutritional plane during pregnancy may be detrimental to the unborn baby, and systematic reviews of the literature on dietary supplementation during pregnancy indicate few benefits and possible risks. In view of this, improved diet before pregnancy deserves greater attention.

Size at birth and cardiovascular responses to psychological stressors: evidence for prenatal programming in women

Background Epidemiological studies have repeatedly shown inverse associations between size at birth and blood pressure in later life. There is some evidence to suggest that exaggerated blood pressure responses to psychological stressors are a forerunner of sustained hypertension. Objective To determine whether individuals who were smaller at birth have greater blood pressure and heart rate responses to psychological stressors. Design Prospective cohort study. Methods A total of 104 men and 79 women (mean age 26.3 years) were recruited from the Adelaide Family Heart Study cohort. Blood pressure was monitored continuously throughout the study using a Portapres and participants undertook a series of three stress tests: Stroop, mirror drawing and public speech. The stress response was defined as the increment from baseline to the mean blood pressure during the three tasks. Results In women, a 1 kg increase in birthweight was associated with an 8.7 mmHg (95% confidence interval: 3.6–13.8, P = 0.001) reduction in the systolic and a 4.1 mmHg (1.6–6.6, P = 0.002) reduction in the diastolic response to stress. The heart rate response to stress was also inversely related to birthweight. These results remained significant after correction for gestational age and other potential confounding factors. Similar results were found for birth length and head circumference. There were no such relationships in men. Conclusions This study provides the first human evidence that cardiovascular responses to psychological stressors may be programmed antenatally and suggests a potential mechanism linking reduced fetal growth with raised blood pressure and cardiovascular disease in later life.

Size at Birth and Autonomic Function During Psychological Stress

Small size at birth is associated with exaggerated blood pressure responses to psychological stressors, which increase the risk of developing sustained hypertension in adult life. Explanatory mechanisms for this association are not well characterized. We investigated the hypothesis that an adverse fetal environment, reflected by small size at birth, persistently alters autonomic nervous system and baroreflex control of cardiovascular function, resulting in exaggerated blood pressure and heart rate responses to stressors. Men and women from an Australian prospective cohort study underwent a series of 3 psychological stressors (Stroop, mirror-tracing, and speech) while their blood pressure was recorded continuously using a Portapres. Indices of autonomic function were derived using spectrum analysis (wavelet packet transform), and baroreflex function was estimated using an adaptive autoregressive model. We found that women who were small at birth demonstrated increased levels of low-frequency blood pressure variability at rest (r=−0.28; P<0.05) and during stress (r=−0.42; P<0.001), reduced levels of high-frequency heart period variability (r=0.22; P<0.05), and reduced baroreflex sensitivity (r=0.34; P<0.01). These findings were not present in the men. This study provides evidence that markers of impaired fetal growth are related to autonomic cardiovascular control involving modulation of both sympathetic and parasympathetic function but in a sex-specific manner. We also provide the first human evidence of a relationship between size at birth and baroreflex function.

In the name of the child The gendered politics of childhood obesity

This paper investigates the ways in which ‘the child’ is positioned in obesity debates and, in doing so, examines the discursive relations between childhood obesity, mothering and child neglect. Using legal cases of parental neglect and an analysis of representations of obesity in Australian print media, we argue that a particular constellation of ‘child politics’ in which children are represented as innocent victims of poor parenting is at play. Parenting, however, is a code for mothers and it is their gendered responsibility for food and families for which they are now being held legally culpable in cases of neglect. The relationship between children and mothers has become the focus of moral discourses around childhood obesity, containing contradictory elements of innocence and risk, responsibility and danger. The intersection of child politics, mothering and individualized responsibility not only illuminates the ways in which gender is absent yet centrally implicated in obesity debates and policy, but also highlights how models of neoliberal governance encompass both State and decentralized forms of power in their attempt to regulate excess bodies.