Mitochondrial Dysfunction in PCOS: Insights into Reproductive Organ Pathophysiology

Polycystic ovary syndrome (PCOS) is a complex, but relatively common endocrine disorder associated with chronic anovulation, hyperandrogenism, and micro-polycystic ovaries. In addition to reduced fertility, people with PCOS have a higher risk of obesity, insulin resistance, and metabolic disease, all comorbidities that are associated with mitochondrial dysfunction. This review summarizes human and animal data that report mitochondrial dysfunction and metabolic dysregulation in PCOS to better understand how mitochondria impact reproductive organ pathophysiology. This in-depth review considers all the elements regulating mitochondrial quantity and quality, from mitochondrial biogenesis under the transcriptional regulation of both the nuclear and mitochondrial genome to the ultrastructural and functional complexes that regulate cellular metabolism and reactive oxygen species production, as well as the dynamics that regulate subcellular interactions that are key to mitochondrial quality control. When any of these mitochondrial functions are disrupted, the energetic equilibrium within the cell changes, cell processes can fail, and cell death can occur. If this process is ongoing, it affects tissue and organ function, causing disease. The objective of this review is to consolidate and classify a broad number of PCOS studies to understand how various mitochondrial processes impact reproductive organs, including the ovary (oocytes and granulosa cells), uterus, placenta, and circulation, causing reproductive pathophysiology. A secondary objective is to uncover the potential role of mitochondria in the transgenerational transmission of PCOS and metabolic disorders.

Impact of Prenatal Exposure to Maternal Diabetes and High-Fat Diet on Postnatal Myocardial Ketone Body Metabolism in Rats

Infants exposed to diabetic pregnancy are at higher risk of cardiomyopathy at birth and early onset cardiovascular disease (CVD) as adults. Using a rat model, we showed how fetal exposure to maternal diabetes causes cardiac disease through fuel-mediated mitochondrial dysfunction, and that a maternal high-fat diet (HFD) exaggerates the risk. Diabetic pregnancy increases circulating maternal ketones which can have a cardioprotective effect, but whether diabetes-mediated complex I dysfunction impairs myocardial metabolism of ketones postnatally remains unknown. The objective of this study was to determine whether neonatal rat cardiomyocytes (NRCM) from diabetes- and HFD-exposed offspring oxidize ketones as an alternative fuel source. To test our hypothesis, we developed a novel ketone stress test (KST) using extracellular flux analyses to compare real-time ß-hydroxybutyrate (βHOB) metabolism in NRCM. We also compared myocardial expression of genes responsible for ketone and lipid metabolism. NRCM had a dose-dependent increase in respiration with increasing concentrations of βHOB, demonstrating that both control and combination exposed NRCM can metabolize ketones postnatally. Ketone treatment also enhanced the glycolytic capacity of combination exposed NRCM with a dose-dependent increase in the glucose-mediated proton efflux rate (PER) from CO2 (aerobic glycolysis) alongside a decreased reliance on PER from lactate (anaerobic glycolysis). Expression of genes responsible for ketone body metabolism was higher in combination exposed males. Findings demonstrate that myocardial ketone body metabolism is preserved and improves fuel flexibility in NRCM from diabetes- and HFD-exposed offspring, which suggests that ketones might serve a protective role in neonatal cardiomyopathy due to maternal diabetes.

Abstract P3056: Influence Of Maternal Diabetes And High Fat Diet On Myocardial Ketone Body Metabolism In The Offspring

Alteration in myocardial substrate utilization and energy metabolism is a well-known contributor to the pathogenesis of heart disease. Recent studies suggest the failing heart may benefit from ketone bodies as an energy source. Infants exposed to diabetic pregnancy are at higher risk of cardiomyopathy at birth and early onset cardiovascular disease (CVD) as adults. We showed fetal exposure to excess circulating fuels, especially to the combination of maternal high fat diet (HFD) and diabetes, exaggerates CVD risk through fuel-mediated mitochondrial dysfunction including complex I dysfunction. Diabetic pregnancy increases ketone body exposure in utero, but whether prenatal exposures impair myocardial metabolism of ketones postnatally remains unknown. The objective of this study was to determine whether neonatal rat cardiomyocytes (NRCM) exposed to maternal diabetes and HFD in utero can increase ketone oxidation as a preferred fuel source over glycolysis. To test our hypothesis, we developed a ketone stress test (KST) or modified extracellular flux analyses to compare real-time ß-hydroxy butyrate (ßOHB) metabolism in NRCM and myocardial expression of genes responsible for ketone and lipid metabolism. While control and combination exposed NRCM had similar basal respiration, the presence of ketone (4.5 mM) increased maximal respiration, spare respiratory capacity, and ATP-limited glycolytic rate in the combination exposed group. Interestingly, baseline proton efflux rate (PER) from lactate (anaerobic glycolysis) decreased while PER from CO 2 (aerobic glycolysis) increased in response to ketones in the combination exposed group. Expression of genes responsible for ketone body metabolism ( Hmgcs2 and Bdh1 ) was not different. The study uses a novel KST to analyze real-time ketone body metabolism and demonstrates myocardial ketone body metabolism is preserved and may be protective in the NRCM exposed to maternal overnutrition.

Uteroplacental Insufficiency with Hypoxia Upregulates Placental PPARγ-KMT5A Axis in the Rat

The placenta represents a critical node in fetal lipid acquisition, yet the mechanisms by which the placenta handles lipids under normal and pathologic conditions are incompletely understood. A key player in placental lipid handling is peroxisome proliferator-activated receptor gamma (PPARγ). PPARγ influences global gene expression via its regulation of the epigenetic modifier lysine methyltransferase 5A (KMT5A), which places a methyl group on histone 4 lysine 20 (H4K20me) of target genes. Here we test the hypothesis that KMT5A is present in both the human and rat placentas and is affected by uteroplacental insufficiency (UPI) in the rat in association with increased placental lipid accumulation. We assessed levels and localization of KMT5A, as well as lipid droplet accumulation, in human placental tissue collected from maternal donors after delivery by planned cesarean section. Using a rat model of UPI, we also evaluated the effects of UPI on lipid accumulation, PPARγ, KMT5A, and H4K20me in the rat placenta. In this study, we show for the first time the presence and activity of KMT5A, in human and in rat placentas. We also demonstrate that in the rat placenta, UPI increases hypoxia, KMT5a expression, and activity in association with increased lipid accumulation in placenta supporting male fetuses. Placental PPARγ-KMT5A axis may be an important mediator of placental lipid handling.

Diamond-Blackfan Anemia: A Case Report and Review of the Literature

We report a case of a male neonate delivered urgently via cesarean at thirty-five 5/7 weeks gestation for non-reassuring fetal monitoring who was found to have severe anemia at birth that could not be explained by acute blood loss. He was born to a 24-year-old mother, whose pregnancy was complicated by abnormal ultrasound findings, including a radial ray defect and fetal growth restriction. Trio rapid whole-exome sequencing (rWES) confirmed Diamond-Blackfan anemia in both the neonate and mother. This case highlights the importance of fetal surveillance and the clinical utility of rWES in the neonatal intensive care setting.

Age and Sex Influence Mitochondria and Cardiac Health in Offspring Exposed to Maternal Glucolipotoxicity

Infants of diabetic mothers are at risk of cardiomyopathy at birth and myocardial infarction in adulthood, but prevention is hindered because mechanisms remain unknown. We previously showed that maternal glucolipotoxicity increases the risk of cardiomyopathy and mortality in newborn rats through fuel-mediated mitochondrial dysfunction. Here we demonstrate ongoing cardiometabolic consequences by cross-fostering and following echocardiography, cardiomyocyte bioenergetics, mitochondria-mediated turnover, and cell death following metabolic stress in aged adults. Like humans, cardiac function improves by weaning with no apparent differences in early adulthood but declines again in aged diabetes-exposed offspring. This is preceded by impaired oxidative phosphorylation, exaggerated age-related increase in mitochondrial number, and higher oxygen consumption. Prenatally exposed male cardiomyocytes have more mitolysosomes indicating high baseline turnover; when exposed to metabolic stress, mitophagy cannot increase and cardiomyocytes have faster mitochondrial membrane potential loss and mitochondria-mediated cell death. Details highlight age- and sex-specific roles of mitochondria in developmentally programmed adult heart disease.

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Fetal exposures disrupt mitochondria, bioenergetics, & cardiac function at birth

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First, bioenergetics & function improve until greater reliance on OXPHOS with age

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At 6MO, poor respiration incites biogenesis & mitophagy, and then functional decline

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Fetal exposures cause faster mitochondria-mediated cell death in aged adult hearts

Maternal High Fat Diet and Diabetes Disrupts Transcriptomic Pathways That Regulate Cardiac Metabolism and Cell Fate in Newborn Rat Hearts

Background: Children born to diabetic or obese mothers have a higher risk of heart disease at birth and later in life. Using chromatin immunoprecipitation sequencing, we previously demonstrated that late-gestation diabetes, maternal high fat (HF) diet, and the combination causes distinct fuel-mediated epigenetic reprogramming of rat cardiac tissue during fetal cardiogenesis. The objective of the present study was to investigate the overall transcriptional signature of newborn offspring exposed to maternal diabetes and maternal H diet. Methods: Microarray gene expression profiling of hearts from diabetes exposed, HF diet exposed, and combination exposed newborn rats was compared to controls. Functional annotation, pathway and network analysis of differentially expressed genes were performed in combination exposed and control newborn rat hearts. Further downstream metabolic assessments included measurement of total and phosphorylated AKT2 and GSK3β, as well as quantification of glycolytic capacity by extracellular flux analysis and glycogen staining. Results: Transcriptional analysis identified significant fuel-mediated changes in offspring cardiac gene expression. Specifically, functional pathways analysis identified two key signaling cascades that were functionally prioritized in combination exposed offspring hearts: (1) downregulation of fibroblast growth factor (FGF) activated PI3K/AKT pathway and (2) upregulation of peroxisome proliferator-activated receptor gamma coactivator alpha (PGC1α) mitochondrial biogenesis signaling. Functional metabolic and histochemical assays supported these transcriptome changes, corroborating diabetes- and diet-induced cardiac transcriptome remodeling and cardiac metabolism in offspring. Conclusion: This study provides the first data accounting for the compounding effects of maternal hyperglycemia and hyperlipidemia on the developmental cardiac transcriptome, and elucidates nuanced and novel features of maternal diabetes and diet on regulation of heart health.

Maternal Tobacco Smoke Exposure Causes Sex-Divergent Changes in Placental Lipid Metabolism in the Rat

Maternal tobacco smoke exposure (MTS) affects fetal acquisition of long-chain polyunsaturated fatty acids (LCPUFA) and increases the risk of obesity and cardio-metabolic disease in the offspring. Alterations in fetal LCPUFA acquisition in maternal smoking are mediated by the placenta. The handling of LCPUFA by the placenta involves protein-mediated transfer and storage. Molecular mediators of placental LCPUFA handling include PPARγ and the fatty acid transport proteins. We previously demonstrated, in a rat model, that MTS results in programming of adult-onset obesity and metabolic disease in male, but not female, offspring. In this study, we test the hypothesis that in utero MTS exposure alters placental structure, placental LCPUFA handling, and fetal fatty acid levels, in a sex-divergent manner. We exposed pregnant rats to tobacco smoke from embryonic day 11 to term gestation. We measured placental and fetal fatty acid profiles, the systolic/diastolic ratio (SD ratio), placental histology, and expression of molecular mediators in the placenta. Our primary finding is that MTS alters fatty acid profiles in male, but not female fetuses and placenta, including increasing the ratio of omega-6 to omega-3 fatty acids. MTS also increased SD ratio in male, but not female placenta. In contrast, the expression of PPARγ and FATPs was upregulated in female, but not male placenta. We conclude that MTS causes sex-divergent changes in placental handling of LCPUFA in the rat. We speculate that our results demonstrate an adaptive response to MTS by the female placenta.

Outcomes of Extremely Preterm Infants With Birth Weight Less Than 400 g

IMPORTANCE

Birth weight (BW) is an important predictor of mortality and morbidity. At extremely early gestational ages (GAs), BW may influence decisions regarding initiation of resuscitation.

OBJECTIVE

To characterize outcomes of liveborn infants with a BW less than 400 g.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective multicenter cohort study analyzed extremely preterm infants born between January 2008 and December 2016 within the National Institute of Child Health and Human Development Neonatal Research Network. Infants with a BW less than 400 g and a GA of 22 to 26 weeks were included. Active treatment was defined as the provision of any potentially lifesaving intervention after birth. Survival was analyzed for the entire cohort; neurodevelopmental impairment (NDI) was examined for those born between January 2008 and December 2015 (birth years with outcomes available for analysis). Neurodevelopmental impairment at 18 to 26 months' corrected age (CA) was defined as a Bayley Scales of Infant and Toddler Development, Third Edition, cognitive composite score less than 85, a motor composite score less than 85, moderate or severe cerebral palsy, gross motor function classification system score of 2 or greater, bilateral blindness, and/or hearing impairment. Data were analyzed from September 2017 to October 2018.

EXPOSURES

Birth weight less than 400 g.

MAIN OUTCOMES AND MEASURES

The primary outcome was survival to discharge among infants who received active treatment. Analysis of follow-up data was limited to infants born from 2008 to 2015 to ensure children had reached assessment age. Within this cohort, neurodevelopmental outcomes were assessed for infants who survived to 18 to 26 months' CA and returned for a comprehensive visit.

RESULTS

Of the 205 included infants, 121 (59.0%) were female, 133 (64.9%) were singletons, and 178 (86.8%) were small for gestational age. Almost half (101 of 205 [49.3%]) received active treatment at birth. A total of 26 of 205 infants (12.7%; 95% CI, 8.5-18.9) overall survived to discharge, and 26 of 101 actively treated infants (25.7%; 95% CI, 17.6-35.4) survived to discharge. Within the subset of infants with a BW less than 400 g and a GA of 22 to 23 weeks, 6 of 36 actively treated infants (17%; 95% CI, 6-33) survived to discharge. Among infants born between 2008 and 2015, 23 of 90 actively treated infants (26%; 95% CI, 17-36) survived to discharge. Two infants died after discharge, and 2 were lost to follow-up. Thus, 19 of 90 actively treated infants (21%; 95% CI, 13-31) were evaluated at 18 to 26 months' CA. Moderate or severe NDI occurred in 14 of 19 infants (74%).

CONCLUSIONS AND RELEVANCE

Infants born with a BW less than 400 g are at high risk of mortality and significant morbidity. Although 21% of infants survived to 18 to 26 months' CA with active treatment, NDI was common among survivors.

Placental lipid processing in response to a maternal high-fat diet and diabetes in rats

BackgroundDiabetes and obesity during pregnancy have an impact on the health of both mothers and developing babies. Prevention focuses on glycemic control, but increasing evidence implicates a role for lipids. Using a rat model, we showed that a maternal high-fat (HF) diet increased perinatal morbidity and mortality, but lipid processing across the maternal-placental-fetal triad remained unstudied. We hypothesized that HF diet would disrupt placental lipid processing to exaggerate fuel-mediated consequences of diabetic pregnancy.MethodsWe compared circulating lipid profiles, hormones, and inflammatory markers in dams and rat offspring from normal, diabetes-exposed, HF-diet-exposed, and combination-exposed pregnancies. Placentae were examined for lipid accumulation and expression of fuel transporters.ResultsMaternal HF diet exaggerated hyperlipidemia of pregnancy, with diabetes marked dyslipidemia developed in dams but not in offspring. Placentae demonstrated lipid accumulation and lower expression of fatty acid (FA) transporters. Diet-exposed offspring had a lower fraction of circulating essential FAs. Pregnancy loss was significantly higher in diet-exposed but not in diabetes-exposed pregnancies, which could not be explained by differences in hormone production. Although not confirmed, inflammation may play a role.ConclusionMaternal hyperlipidemia contributes to placental lipid droplet accumulation, perinatal mortality, and aberrant FA profiles that may influence the health of the developing offspring.

Prenatal Exposure to a Maternal High-Fat Diet Affects Histone Modification of Cardiometabolic Genes in Newborn Rats

Infants born to women with diabetes or obesity are exposed to excess circulating fuels during fetal heart development and are at higher risk of cardiac diseases. We have previously shown that late-gestation diabetes, especially in conjunction with a maternal high-fat (HF) diet, impairs cardiac functions in rat-offspring. This study investigated changes in genome-wide histone modifications in newborn hearts from rat-pups exposed to maternal diabetes and HF-diet. Chromatin-immunoprecipitation-sequencing revealed a differential peak distribution on gene promoters in exposed pups with respect to acetylation of lysines 9 and 14 and to trimethylation of lysines 4 and 27 in histone H3 (all, false discovery rate, FDR < 0.1). In the HF-diet exposed offspring, 54% of the annotated genes showed the gene-activating mark trimethylated lysine 4. Many of these genes (1) are associated with the “metabolic process” in general and particularly with “positive regulation of cholesterol biosynthesis” (FDR = 0.03); (2) overlap with 455 quantitative trait loci for blood pressure, body weight, serum cholesterol (all, FDR < 0.1); and (3) are linked to cardiac disease susceptibility/progression, based on disease ontology analyses and scientific literature. These results indicate that maternal HF-diet changes the cardiac histone signature in offspring suggesting a fuel-mediated epigenetic reprogramming of cardiac tissue in utero.

Breast milk DHA levels may increase after informing women: a community-based cohort study from South Dakota USA

BACKGROUND

Docosahexaenoic acid (DHA), an omega-3 fatty acid found in breast milk, has many health benefits for both mother and baby. A 2007 meta-analysis found U.S. women had breast milk DHA levels (0.20% of total fatty acids) below the worldwide mean (0.32%). In 2008, international dietary recommendations were made for pregnant and lactating women to consume 200 mg of DHA per day. This community-based study aimed to define current milk DHA levels from upper Midwest USA lactating mothers and to determine if providing information about their own level along with dietary recommendations would incite changes to increase breast milk DHA content.

METHODS

New mothers attending lactation classes or using hospital pumping rooms in Sioux Falls, South Dakota, USA participated by providing one drop of breast milk on a card for fatty acid analysis at baseline and 1 month after initial reporting. DHA levels were analyzed by gas chromatography. Mothers received a report of their own breast milk level along with dietary recommendations on DHA intake for lactating women. Median baseline and follow-up DHA levels were determined and differences were compared by Wilcoxon signed-rank test.

RESULTS

At baseline, breast milk DHA content (n = 84) was highly variable (range 0.05 to 0.73%) with a median of 0.18% (IQR, 0.13, 0.28; mean ± SD, 0.22 ± 0.13%), well below the worldwide average (0.32%). Women who reported taking DHA supplements (n = 43) had higher levels than those who did not (0.23% vs. 0.15%, P < 0.0001). In a subset of 60 mothers who submitted a second sample, median breast milk DHA content increased from 0.19 to 0.22% (P < 0.01).

CONCLUSIONS

Findings suggest that providing nursing mothers with their breast milk DHA level and education about DHA intake while breastfeeding motivates change to increase DHA levels.

Consequences of a Maternal High-Fat Diet and Late Gestation Diabetes on the Developing Rat Lung

Rationale

Infants born to diabetic or obese mothers are at risk of respiratory distress and persistent pulmonary hypertension of the newborn (PPHN), conceivably through fuel-mediated pathogenic mechanisms. Prior research and preventative measures focus on controlling maternal hyperglycemia, but growing evidence suggests a role for additional circulating fuels including lipids. Little is known about the individual or additive effects of a maternal high-fat diet on fetal lung development.

Objective

The objective of this study was to determine the effects of a maternal high-fat diet, alone and alongside late-gestation diabetes, on lung alveologenesis and vasculogenesis, as well as to ascertain if consequences persist beyond the perinatal period.

Methods

A rat model was used to study lung development in offspring from control, diabetes-exposed, high-fat diet-exposed and combination-exposed pregnancies via morphometric, histologic (alveolarization and vasculogenesis) and physiologic (echocardiography, pulmonary function) analyses at birth and 3 weeks of age. Outcomes were interrogated for diet, diabetes and interaction effect using ANOVA with significance set at p≤0.05. Findings prompted additional mechanistic inquiry of key molecular pathways.

Results

Offspring exposed to maternal diabetes or high-fat diet, alone and in combination, had smaller lungs and larger hearts at birth. High-fat diet-exposed, but not diabetes-exposed offspring, had a higher perinatal death rate and echocardiographic evidence of PPHN at birth. Alveolar mean linear intercept, septal thickness, and airspace area (D₂) were not significantly different between the groups; however, markers of lung maturity were. Both diabetes-exposed and diet-exposed offspring expressed more T1α protein, a marker of type I cells. Diet-exposed newborn pups expressed less surfactant protein B and had fewer pulmonary vessels enumerated. Mechanistic inquiry revealed alterations in AKT activation, higher endothelin-1 expression, and an impaired Txnip/VEGF pathway that are important for vessel growth and migration. After 3 weeks, mortality remained highest and static lung compliance and hysteresis were lowest in combination-exposed offspring.

Conclusion

This study emphasizes the effects of a maternal high-fat diet, especially alongside late-gestation diabetes, on pulmonary vasculogenesis, demonstrates adverse consequences beyond the perinatal period and directs attention to mechanistic pathways of interest. Findings provide a foundation for additional investigation of preventative and therapeutic strategies aimed at decreasing pulmonary morbidity in at-risk infants.

Age Related Bioenergetics Profiles in Isolated Rat Cardiomyocytes Using Extracellular Flux Analyses

Mitochondrial dysfunction is increasingly recognized and studied as a mediator of heart disease. Extracellular flux analysis (XF) has emerged as a powerful tool to investigate cellular bioenergetics in the context of cardiac health and disease, however its use and interpretation requires improved understanding of the normal metabolic differences in cardiomyocytes (CM) at various stages of maturation. This study standardized XF analyses methods (mitochondrial stress test, glycolytic stress test and palmitate oxidation test) and established age related differences in bioenergetics profiles of healthy CMs at newborn (NB1), weaning (3WK), adult (10WK) and aged (12–18MO) time points. Findings show that immature CMs demonstrate a more robust and sustained glycolytic capacity and a relative inability to oxidize fatty acids when compared to older CMs. The study also highlights the need to recognize the contribution of CO₂ from the Krebs cycle as well as lactate from anaerobic glycolysis to the proton production rate before interpreting glycolytic capacity in CMs. Overall, this study demonstrates that caution should be taken to assure that translatable developmental time points are used to investigate mitochondrial dysfunction as a cause of cardiac disease. Specifically, XF analysis of newborn CMs should be reserved to study fetal/neonatal disease and older CMs (≥10 weeks) should be used to investigate adult disease pathogenesis. Knowledge gained will aid in improved investigation of developmentally programmed heart disease and stress the importance of discerning maturational differences in bioenergetics when developing mitochondrial targeted preventative and therapeutic strategies for cardiac disease.

Maternal high-fat diet impairs cardiac function in offspring of diabetic pregnancy through metabolic stress and mitochondrial dysfunction

Offspring of diabetic pregnancies are at risk of cardiovascular disease at birth and throughout life, purportedly through fuel-mediated influences on the developing heart. Preventative measures focus on glycemic control, but the contribution of additional offenders, including lipids, is not understood. Cellular bioenergetics can be influenced by both diabetes and hyperlipidemia and play a pivotal role in the pathophysiology of adult cardiovascular disease. This study investigated whether a maternal high-fat diet, independently or additively with diabetes, could impair fuel metabolism, mitochondrial function, and cardiac physiology in the developing offspring's heart. Sprague-Dawley rats fed a control or high-fat diet were administered placebo or streptozotocin to induce diabetes during pregnancy and then delivered offspring from four groups: control, diabetes exposed, diet exposed, and combination exposed. Cardiac function, cellular bioenergetics (mitochondrial stress test, glycolytic stress test, and palmitate oxidation assay), lipid peroxidation, mitochondrial histology, and copy number were determined. Diabetes-exposed offspring had impaired glycolytic and respiratory capacity and a reduced proton leak. High-fat diet-exposed offspring had increased mitochondrial copy number, increased lipid peroxidation, and evidence of mitochondrial dysfunction. Combination-exposed pups were most severely affected and demonstrated cardiac lipid droplet accumulation and diastolic/systolic cardiac dysfunction that mimics that of adult diabetic cardiomyopathy. This study is the first to demonstrate that a maternal high-fat diet impairs cardiac function in offspring of diabetic pregnancies through metabolic stress and serves as a critical step in understanding the role of cellular bioenergetics in developmentally programmed cardiac disease.

What is the relationship between gestational age and docosahexaenoic acid (DHA) and arachidonic acid (ARA) levels?

Long chain polyunsaturated fatty acids (LCPUFA) including docosahexaenoic acid (DHA) and arachidonic acid (ARA) are increasingly transferred from mother to fetus late in pregnancy. Infants born before this transfer is complete are at risk for deficiency. This study determines the relationship between gestational age (GA) and circulating LCPUFA levels to better understand the unique needs of premature infants born at various GAs. Whole blood was collected within the first 7 days of life from 60 preterm (≤34 weeks GA) and 30 term infants (≥38 weeks GA) and FA levels were analyzed. Since concurrent intravenous lipid emulsion can skew composition data, blood LCPUFA concentrations were also measured. Levels were compared among groups, and linear regression models were used to examine the association between FA composition and GA. Preterm infants had significantly lower DHA and ARA levels than term peers, and whether assessed as concentrations or compositions, both directly correlated with GA (p<0.0001). Moreover, FA comparisons suggest that premature infants have impaired synthesis of LCPUFAs from precursors and may require preformed DHA and ARA. This study confirms that essential FA status is strongly related to GA, and that those babies born the earliest are at the greatest risk of LCPUFA deficiency.

Hyperglycemia induces embryopathy, even in the absence of systemic maternal diabetes: an in vivo test of the fuel mediated teratogenesis hypothesis

Embryonic exposure to excess circulating fuels is proposed to underlie diabetic embryopathy. To isolate the effects of hyperglycemia from the many systemic anomalies of diabetes, we infused 4 mg/min glucose into the left uterine artery of non-diabetic pregnant rats on gestation days (GD) 7-9. Right-sided embryos and dams exhibited no glucose elevation. Embryos were assessed on GD13, comparing the left versus right uterine horns. Hyperglycemic exposure increased rates of embryopathy, resorptions, and worsened embryopathy severity. By contrast, saline infusion did not affect any of these parameters. To assess for possible embryopathy susceptibility bias between uterine horns, separate dams were given retinoic acid (25mg/kg, a mildly embryopathic dose) systemically on GD7.5. The resultant embryopathy rates were equivalent between uterine horns. We conclude that hyperglycemia, even in the absence of systemic maternal diabetes, is sufficient to produce in vivo embryopathy during organogenesis.

Long-chain polyunsaturated fatty acid levels in US donor human milk: meeting the needs of premature infants?

OBJECTIVE

To determine fatty acid levels in the US donor milk supply.

STUDY DESIGN

Donor human milk samples from Iowa (n=62), Texas (n=5), North Carolina (n=5) and California (n=5) were analyzed by gas chromatography. Levels in the Iowa donor milk were compared before and after pasteurization using Student's t-test. Docosahexaenoic acid (DHA) and arachidonic acid (ARA) levels were compared among all milk banks using analysis of variance.

RESULT

ARA (0.4 pre, 0.4 post, P=0.18) and DHA (0.073 pre, 0.073 post, P=0.84) were not affected by pasteurization. DHA varied between banks (P<0.0001), whereas ARA did not (P=0.3). DHA levels from all banks were lower than published values for maternal milk and infant formula (P<0.0001).

CONCLUSION

Pasteurization of breastmilk does not affect DHA or ARA levels. However, DHA content in US donor milk varies with bank location and may not meet the recommended provision for preterm infants.