Deborah M. Sloboda

Maternal nutritional history predicts obesity in adult offspring independent of postnatal diet

Significant alterations in maternal nutrition may induce long‐term metabolic consequences in offspring, in particular obesity and leptin and insulin resistance. Although maternal nutrient deprivation has been well characterized in this context, there is a relative paucity of data on how high fat (HF) nutrition impacts on the subsequent generation. The present study investigated the effects of maternal HF nutrition either throughout the mothers life up to and including pregnancy and lactation or HF nutrition restricted to pregnancy and lactation, on growth and metabolic parameters in male and female offspring. Virgin Wistar rats were assigned to one of three experimental groups: (1) controls (Cont): dams fed a standard chow diet throughout their life and throughout pregnancy and lactation; (2) maternal high fat (MHF) group: dams fed a HF diet from weaning up to and throughout pregnancy and lactation; and (3) pregnancy and lactation high fat (PLHF): dams fed a chow diet through their life until conception and then fed a HF diet throughout pregnancy and lactation. At weaning, all offspring were fed either a chow or HF diet for the remainder of the study (160 days). Litter size and sex ratios were not significantly different between the groups. MHF and PLHF offspring had significantly lower body weights and were hypoleptinaemic and hypoinsulinaemic at birth compared to Cont offspring. As adults however, chow‐fed MHF and PLHF offspring were significantly more obese than Cont offspring (DEXA scanning at day 150, P < 0.001 for maternal HF diet). As expected a postweaning HF diet resulted in increased adiposity in all groups; MHF and PLHF offspring, however, always remained significantly more obese than Cont offspring. Increased adiposity in MHF and PLHF offspring was paralleled by hyperinsulinaemia and hyperleptinaemia (P < 0.001; MHF and PLHF versus Cont). It is of interest that a lifetime of HF nutrition produced a similar offspring phenotype to HF nutrition restricted to pregnancy and lactation alone, thus suggesting that the postnatal sequelae of maternal HF nutrition occurs independent of preconceptional diet. These data further reinforce the importance of maternal nutrition during these critical windows of development and show that maternal HF feeding can induce a markedly obese phenotype in male and female offspring completely independent of postnatal nutrition.

Pre- and postnatal nutritional histories influence reproductive maturation and ovarian function in the rat.

Background While prepubertal nutritional influences appear to play a role in sexual maturation, there is a need to clarify the potential contributions of maternal and childhood influences in setting the tempo of reproductive maturation. In the present study we employed an established model of nutritional programming to evaluate the relative influences of prenatal and postnatal nutrition on growth and ovarian function in female offspring. Methods Pregnant Wistar rats were fed either a calorie-restricted diet, a high fat diet, or a control diet during pregnancy and/or lactation. Offspring then were fed either a control or a high fat diet from the time of weaning to adulthood. Pubertal age was monitored and blood samples collected in adulthood for endocrine analyses. Results We report that in the female rat, pubertal timing and subsequent ovarian function is influenced by the animals nutritional status in utero, with both maternal caloric restriction and maternal high fat nutrition resulting in early pubertal onset. Depending on the offsprings nutritional history during the prenatal and lactational periods, subsequent nutrition and body weight gain did not further influence offspring reproductive tempo, which was dominated by the effect of prenatal nutrition. Whereas maternal calorie restriction leads to early pubertal onset, it also leads to a reduction in adult progesterone levels later in life. In contrast, we found that maternal high fat feeding which also induces early maturation in offspring was associated with elevated progesterone concentrations. Conclusions These observations are suggestive of two distinct developmental pathways leading to the acceleration of pubertal timing but with different consequences for ovarian function. We suggest different adaptive explanations for these pathways and for their relationship to altered metabolic homeostasis.

Offspring of Mothers Fed a High Fat Diet Display Hepatic Cell Cycle Inhibition and Associated Changes in Gene Expression and DNA Methylation

The association between an adverse early life environment and increased susceptibility to later-life metabolic disorders such as obesity, type 2 diabetes and cardiovascular disease is described by the developmental origins of health and disease hypothesis. Employing a rat model of maternal high fat (MHF) nutrition, we recently reported that offspring born to MHF mothers are small at birth and develop a postnatal phenotype that closely resembles that of the human metabolic syndrome. Livers of offspring born to MHF mothers also display a fatty phenotype reflecting hepatic steatosis and characteristics of non-alcoholic fatty liver disease. In the present study we hypothesised that a MHF diet leads to altered regulation of liver development in offspring; a derangement that may be detectable during early postnatal life. Livers were collected at postnatal days 2 (P2) and 27 (P27) from male offspring of control and MHF mothers (n = 8 per group). Cell cycle dynamics, measured by flow cytometry, revealed significant G0/G1 arrest in the livers of P2 offspring born to MHF mothers, associated with an increased expression of the hepatic cell cycle inhibitor Cdkn1a. In P2 livers, Cdkn1a was hypomethylated at specific CpG dinucleotides and first exon in offspring of MHF mothers and was shown to correlate with a demonstrable increase in mRNA expression levels. These modifications at P2 preceded observable reductions in liver weight and liver∶brain weight ratio at P27, but there were no persistent changes in cell cycle dynamics or DNA methylation in MHF offspring at this time. Since Cdkn1a up-regulation has been associated with hepatocyte growth in pathologic states, our data may be suggestive of early hepatic dysfunction in neonates born to high fat fed mothers. It is likely that these offspring are predisposed to long-term hepatic dysfunction.

The Relationship between Maternal and Umbilical Cord Androgen Levels and Polycystic Ovary Syndrome in Adolescence: A Prospective Cohort Study

CONTEXT The prenatal antecedents of polycystic ovary syndrome (PCOS) are not known, but prenatal androgen exposure is thought to contribute. This has not previously been investigated in large prospective studies of normal human pregnancy. OBJECTIVE The aim of the study was to establish the prospective relationship between early life androgen exposure and PCOS in adolescence. DESIGN AND SETTING A prospective cohort study was conducted in the general community. PATIENTS OR OTHER PARTICIPANTS A total of 2900 pregnant women were recruited at 18 wk gestation. Prenatal androgen exposure was measured from maternal blood samples (at 18 and 34-36 wk) and umbilical cord blood. Timed (d 2-5 menstrual cycle) blood samples were collected, clinical hyperandrogenism was assessed, and transabdominal ultrasound examination of ovarian morphology was performed in 244 unselected girls from the Raine cohort aged 14-17 yr. MAIN OUTCOME MEASURE(S) We examined the relationship between early life androgen exposure and PCOS in adolescence. RESULTS We did not observe a statistically significant relationship between early life androgen exposure and PCOS in adolescence. CONCLUSIONS This is the first prospective study to evaluate the relationship between prenatal androgen exposure and PCOS in adolescence in normal pregnancy. Our findings do not support the hypothesis that maternal androgens, within the normal range for pregnancy, directly program PCOS in the offspring.

Synthetic Glucocorticoids: Antenatal Administration and Long-term Implications

A clear relationship between intrauterine development and later life predisposition to long-term disease is well established. Weight at birth provides a surrogate measure for fetal development and low birth weight predicts changes in most endocrine axes in adulthood. The exposure of the fetus to elevated levels of either endogenous or synthetic glucocorticoids, pre and periconceptional nutritional status and immediate postnatal development including catch-up growth all contribute substantially to the development of adult onset disease. Fetal exposure to high levels of glucocorticoids has direct clinical relevance. Synthetic glucocorticoids (betamethasone/ dexamethasone) are administered to women at risk of preterm delivery to advance fetal maturation and reduce neonatal morbidity and mortality. However, in human pregnancy, evidence suggests that fetal exposure to synthetic glucocorticoids has detrimental effects on birth outcome, childhood cognition and long-term behavior. Studies in animals have established a link between prenatal exposure to synthetic glucocorticoids and alterations in fetal development as well as changes in placental function. These developmental alterations appear to be permanent. Whether this is the case in humans awaits long-term follow-up of children enrolled in randomized controlled trials of prenatal glucocorticoid therapy. The research challenges in this field are now centered on uncovering the mechanisms by which glucocorticoids are involved in programming the fetus for its future life, and discovering ways in which the effectiveness and safety of antenatal glucocorticoids can be enhanced. The purpose of this mini-review is to provide a background into the use of antenatal synthetic corticosteroids and to highlight and summarize recently published clinical and animal-based studies.

Nature, nurture or nutrition? Impact of maternal nutrition on maternal care, offspring development and reproductive function

•  Maternal high fat nutrition during pregnancy and lactation significantly reduced maternal care during the early neonatal period; but reduced maternal care was not associated with an offspring phenotype. •  Maternal high fat nutrition resulted in maternal obesity characterized by increased fat mass, hyperleptinaemia, hyperinsulinaemia. •  Maternal high fat nutrition resulted in fatter offspring before puberty and advanced pubertal onset. •  Adult female offspring of high fat‐fed mothers have altered reproductive function, reflected in an increased likelihood of prolonged or persistent oestrus. •  These phenotypic effects were not related to maternal care suggesting that poor maternal nutrition, rather than inadequate maternal care, could be the primary driver of the observed alterations in offspring development and reproductive function.

Clinical, ultrasound and biochemical features of polycystic ovary syndrome in adolescents: implications for diagnosis

BACKGROUND Diagnosing polycystic ovary syndrome (PCOS) in adolescence is clinically challenging. The prevalence of clinical, ultrasound and biochemical features of PCOS in a community-based adolescent population using current diagnostic criteria has not previously been described. METHODS This was a prospective cohort study with 244 unselected post-menarchal girls, mean age 15.2 years, of whom 91% were Caucasian. Subjects were recruited from a large population-based birth cohort (the Raine cohort). Clinical hyperandrogenism (HA) was quantified using Ferriman-Gallwey scores. In the early follicular phase (Day 2-6), we measured circulating androgens and sex hormone-binding globulin by immunoassay, and ovarian morphology was assessed by transabdominal ultrasound examination. BMI and waist-hip ratio were measured. RESULTS Normal ranges for early follicular phase androgens in adolescence were derived for this population. The top 5 and 10% of circulating free testosterone levels were 45.6 and 34.5 pmol/l, respectively. Fifty-one percent of girls reported menstrual irregularity. Clinical HA was uncommon, being observed in only 3.5% of girls. Mean ovarian volume was greater than that reported by others in adult women and 35% of girls had polycystic ovary morphology on transabdominal ultrasound. Taking the upper 5% of free testosterone as HA, 42 girls (18.5%) would have met the Rotterdam criteria for PCOS, 11 girls (5%) the Androgen Excess Society criteria and 7 girls (3.1%) the National Institutes of Health criteria. CONCLUSIONS Menstrual irregularity is common in adolescence and does not relate to clinical or biochemical HA. Diagnostic criteria for PCOS which include ovarian volume and morphology may be of limited use in adolescence.

Maternal Fructose Intake during Pregnancy and Lactation Alters Placental Growth and Leads to Sex-Specific Changes in Fetal and Neonatal Endocrine Function

The effects of maternal fructose intake on offspring health remain largely unknown, despite the marked increase in consumption of sweetened beverages that has paralleled the obesity epidemic. The present study investigated the impact of maternal fructose intake on placental, fetal, and neonatal development. Female Wistar rats were time-mated and allocated to receive either water [control (CONT)] or fructose solution designed to provide 20% of caloric intake from fructose (FR). FR was administered from d 1 of pregnancy until postnatal day (P) 10. All dams had ad libitum access to standard laboratory chow and water. Dams and offspring were killed at embryonic day (E) 21 and P10. FR dams demonstrated increased total caloric intake and maternal hyperinsulinemia at E21 as well as increased maternal plasma fructose levels at E21 and P10. FR intake did not alter maternal blood glucose, β-hydroxybutyrate (BHB), or electrolyte levels at either time point. Fetal weights at E21 were unchanged, although placental weights were reduced in FR female but not FR male fetuses. Plasma leptin, fructose, and blood glucose levels were increased and BHB levels decreased in FR female but not male fetuses. Plasma insulin levels were not different between CONT and FR groups. Male and female FR neonates had higher plasma fructose levels and were hypoinsulinemic but euglycemic at P10 compared with CONT. Blood BHB levels were increased in FR male neonates but not females at P10. P10 plasma leptin levels were not different between groups. Stomach content leptin levels were increased in all FR offspring at P10, but no differences in stomach content insulin or fructose levels were observed. This study reports for the first time that maternal FR intake resulted in sex-specific changes in offspring development, whereby females appear more vulnerable to metabolic compromise during neonatal life. Independent follow-up studies are essential to investigate the long-term consequences of maternal FR consumption on offspring health.

Maternal undernutrition significantly impacts ovarian follicle number and increases ovarian oxidative stress in adult rat offspring.

Background We have shown recently that maternal undernutrition (UN) advanced female pubertal onset in a manner that is dependent upon the timing of UN. The long-term consequence of this accelerated puberty on ovarian function is unknown. Recent findings suggest that oxidative stress may be one mechanism whereby early life events impact on later physiological functioning. Therefore, using an established rodent model of maternal UN at critical windows of development, we examined maternal UN-induced changes in offspring ovarian function and determined whether these changes were underpinned by ovarian oxidative stress. Methodology/Principal Findings Our study is the first to show that maternal UN significantly reduced primordial and secondary follicle number in offspring in a manner that was dependent upon the timing of maternal UN. Specifically, a reduction in these early stage follicles was observed in offspring born to mothers undernourished throughout both pregnancy and lactation. Additionally, antral follicle number was reduced in offspring born to all mothers that were UN regardless of whether the period of UN was restricted to pregnancy or lactation or both. These reductions were associated with decreased mRNA levels of genes critical for follicle maturation and ovulation. Increased ovarian protein carbonyls were observed in offspring born to mothers UN during pregnancy and/or lactation and this was associated with peroxiredoxin 3 hyperoxidation and reduced mRNA levels; suggesting compromised antioxidant defence. This was not observed in offspring of mothers UN during lactation alone. Conclusions We propose that maternal UN, particularly at a time-point that includes pregnancy, results in reduced offspring ovarian follicle numbers and mRNA levels of regulatory genes and may be mediated by increased ovarian oxidative stress coupled with a decreased ability to repair the resultant oxidative damage. Together these data are suggestive of maternal UN potentially contributing to premature ovarian ageing in offspring.

Serum antimullerian hormone (AMH) levels are elevated in adolescent girls with polycystic ovaries and the polycystic ovarian syndrome (PCOS)

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder in adolescents, with potentially significant lifelong consequences. This prospective study set out to determine if the investigators could derive a threshold value of antimullerian hormone (AMH) that would predict its presence according to two internationally recognized definitions using a simple measurement, avoiding more extensive and potentially more invasive investigations. The study failed to demonstrate, in a general adolescent population, that serum AMH is a reliable predictor of PCO morphology or for the presence of PCOS.