Validity of self-reported hysterectomy and oophorectomy in a population-based cohort: The HUNT study.

OBJECTIVE: To validate self-reported hysterectomy and bilateral oophorectomy. DESIGN: Validation study. SETTING: Large population-based cohort study in Norway: The Trøndelag Health Study (HUNT). POPULATION: The Trøndelag Health Study 2 and 3 (HUNT2 and HUNT3) included questions on gynaecological history. Women who answered questions regarding hysterectomy and/or oophorectomy were included. In total, 30 263 women were included from HUNT2 (1995-1997) and 23 138 from HUNT3 (2006-2008), of which 16 261 attended both HUNT2 and HUNT3. METHODS: We compared self-reported hysterectomy and bilateral oophorectomy with electronic hospital procedure codes. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value and negative predictive value of self-reported hysterectomy and bilateral oophorectomy, by comparing with hospital procedure codes. RESULTS: Self-reported hysterectomy and bilateral oophorectomy in HUNT2 and/or HUNT3 both had specificity and negative predictive value above 99%. Self-reported hysterectomy had a sensitivity of 95.9%, and for bilateral oophorectomy sensitivity was 91.2%. Positive predictive value of self-reported hysterectomy was 85.8%, but for self-reported bilateral oophorectomy it was 65.4%. CONCLUSIONS: Self-reported hysterectomy corresponded quite well with hospital data and can be used in epidemiological studies. Self-reported bilateral oophorectomy, on the other hand, had low positive predictive value, and results based on such data should be interpreted with caution. Women who report no previous hysterectomy or bilateral oophorectomy can safely be classified as unexposed to these surgeries.

Placental energy metabolism: Evidence for a placental-maternal lactate-ketone trade in the human.

INTRODUCTION: Glucose from placenta is the predominant energy source for the fetus. Individual placentas exhibit a range of glucose handling from apparent net production to high consumption, presumably reflecting an ability of placenta to secure both own and fetal energy needs. A dependency of placenta on glucose as the main energy source could impede fetal supply. Placenta seems to release lactate to maternal side implying loss of energy. Whether placenta takes up ketones is unclear. Our main hypothesis was that the human placenta can release lactate to the maternal side but take up maternal ketones. METHODS: An in vivo study of term uncomplicated pregnancies including 56 women delivered by cesarean section. We measured uterine and umbilical blood flow by Doppler ultrasonography, combined with blood sampling from maternal radial artery, uterine vein, umbilical artery and vein. Lactate and ketones were determined by quantitative nuclear magnetic resonance. RESULTS: Placenta released lactate to the maternal side (median -36.65 µmol/min. Q1, Q3: 78.53, 13.29), p < 0.001), but not to the fetal side. A net uptake of maternal ketones was found (median (Q1, Q3): 59.12 (30.64, 131.46) µmol acetate equivalents/min, p < 0.001) which largely was metabolized by the uteroplacenta. The uptake of ketones was comparable in energy to the loss of lactate. DISCUSSION: Placenta may release lactate to the maternal side. The energy lost by lactate may be compensated by uptake of maternal ketones. This lactate-ketone trade could benefit both placenta and the fetus by providing lactate for maternal gluconeogenesis and ketones for uteroplacental oxidative energy production.

Placental weight, surface area, shape and thickness - Relations with maternal ethnicity and cardio-metabolic factors during pregnancy.

INTRODUCTION: A better understanding of the determinants of placental growth is needed. Our primary aim was to explore associations between maternal ethnic origin and cardio-metabolic factors during pregnancy, and placental weight, surface area, shape and thickness. METHODS: A multi-ethnic population-based cohort study of 474 pregnant women examined at mean 15 and 28 weeks' gestation. Placentas were inspected after birth by a placental pathologist. Outcome measures were trimmed placental weight and three uncorrelated placental components; surface area, shape (oval vs round) and thickness, created through a principal components analysis. Multivariate linear regression models were used to explore the associations with maternal factors. RESULTS: Compared with ethnic European women, mothers with South- and East Asian ethnicity had placentas with lower weight (-51 g (95% CI: 75, -27) and -55 g (-95, -14) respectively), primarily due to a smaller surface area. The association between South Asian ethnicity and placental surface area was still significant after adjusting for maternal characteristics and cardio-metabolic factors. Fat mass index in early pregnancy was associated with higher placental weight and thickness. Placental surface area was positively associated with mid-gestational increases in fat mass, fasting glucose and triglycerides and with the 2-h glucose value at the 28 week oral glucose tolerance test, and inversely with a mid-gestational increase in HDL-cholesterol. DISCUSSION: Mid-gestational changes in fat mass, glucose, triglycerides and cholesterol were associated with, but only partly explained ethnic differences in placental surface area, while maternal fat mass in early pregnancy was associated with placental thickness.

Maternal body mass index, birthweight, and placental glucose metabolism: evidence for a role of placental hexokinase.

BACKGROUND: The principal fetal energy source is glucose provided by the placental transfer of maternal glucose. However, the placenta's glucose consumption exhibits considerable variation. Hexokinase is the first and one of the rate-limiting enzymes of glycolysis that phosphorylates glucose to glucose-6-phosphate. The role of placental hexokinase activity in human placental glucose metabolism is unknown. OBJECTIVE: This study aimed to test the hypothesis that placental hexokinase activity is related to maternal body mass index, placental glucose uptake and consumption, and birthweight. STUDY DESIGN: Overall, 67 healthy pregnant participants at term were included in this study at Oslo University Hospital, Oslo, Norway. Placental hexokinase activity was measured by using a colorimetric assay. The mass of glucose taken up by the uteroplacental unit and the fetus was obtained by measuring arteriovenous glucose differences combined with Doppler assessment of uterine and umbilical blood flow. Blood samples were obtained from the maternal radial artery, uterine vein, and umbilical artery and vein. The uteroplacental glucose consumption constituted the difference between uteroplacental and fetal glucose uptakes. The Spearman rank correlation was performed for statistical analyses to study the correlation of placental hexokinase activity (milliunit per milligram of protein) with prepregnancy body mass index, maternal glucose and insulin, birthweight, uteroplacental glucose uptake and consumption, and fetal glucose uptake (micromole per minute). Partial rank correlation analysis was performed when controlling for hours of fasting or placental weight. RESULTS: Hexokinase activity was detectable in all placental tissue samples. The mean activity was 19.6 (standard deviation, 4.64) mU/mg protein. Placental hexokinase activity correlated positively with prepregnancy body mass index (Spearman rho=0.33; P=.006). On controlling for hours of fasting, hexokinase activity showed positive correlations with both maternal glucose (r=0.30; P=.01) and insulin (r=0.28; P=.02). Hexokinase activity was positively correlated with uteroplacental glucose uptake (Spearman rho=0.31; P=.01) and consumption (Spearman rho=0.28; P=.02). Hexokinase activity did not correlate with fetal glucose uptake. On controlling for placental weight, hexokinase activity showed a positive correlation with birthweight (r=0.31; P=.01). CONCLUSION: Our findings suggest that placental hexokinase, being crucial for uteroplacental retention of glucose for disposition, is related to both maternal body mass index and birthweight independent of placental weight. Placental hexokinase may play a central role in the relationship between maternal glucose dysregulation and fetal growth. Thus, the current study supports the need to develop clinically useful tools to assess the metabolic properties of the placenta.

Maternal prenatal cholesterol levels predict offspring weight trajectories during childhood in the Norwegian Mother, Father and Child Cohort Study.

BACKGROUND: Numerous intrauterine factors may affect the offspring's growth during childhood. We aimed to explore if maternal and paternal prenatal lipid, apolipoprotein (apo)B and apoA1 levels are associated with offspring weight, length, and body mass index from 6 weeks to eight years of age. This has previously been studied to a limited extent. METHODS: This parental negative control study is based on the Norwegian Mother, Father and Child Cohort Study and uses data from the Medical Birth Registry of Norway. We included 713 mothers and fathers with or without self-reported hypercholesterolemia and their offspring. Seven parental metabolites were measured by nuclear magnetic resonance spectroscopy, and offspring weight and length were measured at 12 time points. Data were analyzed by linear spline mixed models, and the results are presented as the interaction between parental metabolite levels and offspring spline (age). RESULTS: Higher maternal total cholesterol (TC) level was associated with a larger increase in offspring body weight up to 8 years of age (0.03 ≤ Pinteraction ≤ 0.04). Paternal TC level was not associated with change in offspring body weight (0.17 ≤ Pinteraction ≤ 0.25). Higher maternal high-density lipoprotein cholesterol (HDL-C) and apoA1 levels were associated with a lower increase in offspring body weight up to 8 years of age (0.001 ≤ Pinteraction ≤ 0.005). Higher paternal HDL-C and apoA1 levels were associated with a lower increase in offspring body weight up to 5 years of age but a larger increase in offspring body weight from 5 to 8 years of age (0.01 ≤ Pinteraction ≤ 0.03). Parental metabolites were not associated with change in offspring height or body mass index up to 8 years of age (0.07 ≤ Pinteraction ≤ 0.99). CONCLUSIONS: Maternal compared to paternal TC, HDL-C, and apoA1 levels were more strongly and consistently associated with offspring body weight during childhood, supporting a direct intrauterine effect.

All-cause and cardiovascular mortality after hysterectomy and oophorectomy in a large cohort (HUNT2).

INTRODUCTION: Hysterectomy and bilateral oophorectomy are common major surgical procedures that have been associated with increased mortality risk. We aimed to assess the association of hysterectomy and/or bilateral oophorectomy with all-cause and cardiovascular mortality in a Norwegian population. MATERIAL AND METHODS: Cohort study with data from The Trøndelag Health Study (HUNT2) linked to the Norwegian Cause of Death Registry, with follow-up from 1996 until 2014 or death. The unexposed group (n = 18 673) included women with both their ovaries and uterus intact, while the two exposed groups included women with hysterectomy alone (n = 1199), or bilateral oophorectomy with or without hysterectomy (n = 907). We compared mortality in exposed vs unexposed groups and adjusted for relevant covariates by Cox regression. Further, we performed analyses stratified by age at surgery (≤39, 40-52, ≥53 years) and subgroup analyses among women ≤52 years of age at inclusion. RESULTS: Among the 47 312 women in HUNT2 (1995-1997), 20 779 provided complete information regarding gynecological surgery and previous health. The hysterectomy group had increased all-cause mortality (hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.06-1.58) and cardiovascular mortality (HR 1.47, 95% CI 1.09-1.97). We found no significant association between bilateral oophorectomy and all-cause or cardiovascular mortality in the total population. However, among women ≤52 years at inclusion, cardiovascular mortality was increased in the hysterectomy group (HR 2.71, 95% CI 1.19-6.17) with a similar, but less precise estimate in the bilateral oophorectomy group (HR 2.42, 95% CI 0.84-6.93). CONCLUSIONS: Hysterectomy was associated with increased all-cause and cardiovascular mortality, whereas bilateral salpingo-oophorectomy was not. Among women ≤52 years at inclusion, both hysterectomy and bilateral oophorectomy were associated with a twofold increased risk of cardiovascular mortality, but the results were imprecise. Women after hysterectomy and/or bilateral salpingo-oophorectomy constitute a group with increased cardiovascular mortality that may need closer attention to cardiovascular disease risk from the healthcare system to ensure timely and effective preventive interventions.

Metabolic profiling of pregnancies complicated by preeclampsia: A longitudinal study.

INTRODUCTION: Preeclampsia is associated with maternal metabolic disturbances, but longitudinal studies with comprehensive metabolic profiling are lacking. We aimed to determine metabolic profiles across gestation in women who developed preeclampsia compared with women with healthy pregnancies. We also explored the respective effects of body mass index (BMI) and preeclampsia on various metabolic measures. MATERIAL AND METHODS: We measured 91 metabolites by high-throughput nuclear magnetic resonance spectroscopy at four time points (visits) during pregnancy (weeks 14-16, 22-24, 30-32 and 36-38). Samples were taken from a Norwegian pregnancy cohort. We fitted a linear regression model for each metabolic measure to compare women who developed preeclampsia (n = 38) and healthy controls (n = 70). RESULTS: Among women who developed preeclampsia, 92% gave birth after 34 weeks of gestation. Compared to women with healthy pregnancies, women who developed preeclampsia had higher levels of several lipid-related metabolites at visit 1, whereas fewer differences were observed at visit 2. At visit 3, the pattern from visit 1 reappeared. At visit 4 the differences were larger in most subgroups of very-low-density lipoprotein particles, the smallest high-density lipoprotein, total lipids and triglycerides. Total fatty acids were also increased, of which monounsaturated fatty acids and saturated fatty acids showed more pronounced differences. Concentration of glycine tended to be lower in pregnancies with preeclampsia until visit 3, although this was not significant after correction for multiple testing. After adjustment for age, BMI, parity and gestational weight gain, all significant differences were attenuated at visits 1 and 2. The estimates were less affected by adjustment at visits 3 and 4. CONCLUSIONS: In early pregnancy, the metabolic differences between preeclamptic and healthy pregnancies were primarily driven by maternal BMI, probably representing the women's pre-pregnancy metabolic status. In early third trimester, several weeks before clinical manifestation, the differences were less influenced by BMI, indicating preeclampsia-specific changes. Near term, women with preeclampsia developed an atherogenic metabolic profile, including elevated total lipids, very-low-density lipoprotein, triglycerides, and total fatty acids.

Uteroplacental versus fetal use of glucose in healthy pregnancies at term. A human in vivo study.

INTRODUCTION: Fetal glucose is thought to originate from maternal glucose driven across the placenta by a maternal-fetal glucose gradient. Still, there is no correlation between the mass of glucose taken up by the uteroplacenta and the fetal uptake. We propose a hypothesis that the uteroplacenta's own treatment of glucose affects the net mass of glucose taken up by the fetus, independent of the maternal-fetal gradient. METHODS: We performed a human in vivo study of term uncomplicated pregnancies including seventy healthy women delivered by scheduled cesarean delivery. We measured uterine and umbilical blood flow by Doppler ultrasonography, and glucose concentrations in the maternal radial artery, uterine vein, umbilical artery and vein. We calculated Spearman's correlations between uteroplacental and fetal glucose uptake within tertiles of placental glucose consumption. RESULTS: There were significant correlations between uteroplacental uptake and fetal uptake of glucose when determined within each tertile (Spearman's rho 0.76, (p < 0.001); 0.94 (p < 0.001) and 0.49 (p = 0.029) from lowest to highest tertile, respectively). The median (Q1, Q3) uteroplacental glucose consumption in each tertile was -88.8 (-140.3, 56.7), 29.7 (9.2, 47.4) and 174.7 (87.8, 226.1) (µmol/min). The corresponding median (Q1, Q3) fetal glucose uptake was 152.9 (94.2, 162.7), 110.8 (54.7, 167.2) and 66.6 (8.5, 122.1) (µmol/min). DISCUSSION: The maternal fetal glucose gradients were similar in the tertiles of placental glucose consumption. Still, the net mass of glucose taken up by the fetus was markedly different between the tertiles. Placental treatment of glucose exhibited a large variation from apparent production to consumption.

Lipid and lipoprotein concentrations during pregnancy and associations with ethnicity.

BACKGROUND: To describe ethnic differences in concentrations of lipids and lipoproteins, and their changes, during pregnancy to postpartum. METHODS: This was a population-based cohort study conducted in primary antenatal care in Norway. The participants (n = 806) were healthy, pregnant women, 59% were ethnic minorities. Outcomes were triglycerides, total cholesterol, HDL- and LDL-cholesterol, analysed from fasting blood samples drawn at gestational age (weeks) 15, 28 and 14 weeks postpartum. We performed linear regression models and linear mixed models to explore the total effect of ethnicity on the outcomes, adjusting for gestational age /week postpartum, maternal age and education. The analyses are corrected for multiple testing using the Bonferroni correction. RESULTS: At gestational age 15, triglyceride concentrations were lower in women of African origin (1.03 mmol/mol (95% CI: 0.90, 1.16)) and higher in women of South Asian (primarily Pakistan and Sri Lanka) origin (1.42 mmol/mol (1.35, 1.49)) and East Asian (primarily Vietnam, Philippines and Thailand) origin (1.58 mmol/mol (1.43, 1.73)) compared with Western Europeans (1.26 mmol/mol (1.20, 1.32)). Women of Asian and African origin had a smaller increase in triglycerides, LDL- and total cholesterol from gestational age 15 to 28. At gestational age 28, LDL-cholesterol levels were lowest among East Asians (3.03 mmol/mol (2.72, 3.34)) compared with Western Europeans (3.62 mmol/mol (3.50, 3.74)). Triglycerides and HDL-cholesterol were lower postpartum than at gestational age 15 in all groups, but the concentration of LDL-cholesterol was higher, except in Africans. South and East Asian women had lower HDL-cholesterol and higher triglycerides postpartum, while African women had lower triglycerides than Western Europeans. CONCLUSION: We found significant differences in the concentrations of lipids and lipoproteins and their changes during pregnancy and the early postpartum period related to ethnic origin.

Insulin Increases Adipose Adiponectin in Pregnancy by Inhibiting Ubiquitination and Degradation: Impact of Obesity.

CONTEXT: Circulating adiponectin levels are decreased in pregnant women with obesity or gestational diabetes, and this is believed to contribute to the insulin resistance and increased risk of fetal overgrowth associated with these conditions. However, the molecular mechanisms regulating adiponectin secretion from maternal adipose tissues in pregnancy are poorly understood. OBJECTIVE: We tested the hypothesis that obesity in pregnancy is associated with adipose tissue insulin resistance and increased adiponectin ubiquitination and degradation, caused by inflammation and endoplasmic reticulum (ER) stress. METHODS: Visceral adipose tissues were collected from lean and obese pregnant humans and mice. Total and ubiquitinated adiponectin, and markers of inflammation, ER stress, and insulin resistance were examined in adipose tissues. The role of insulin, inflammation, and ER stress in mediating adiponectin ubiquitination and degradation was examined using 3T3L-1 adipocytes. RESULTS: Obesity in pregnancy is associated with adipose tissue inflammation, ER stress, insulin resistance, increased adiponectin ubiquitination, and decreased total abundance of adiponectin. Adiponectin ubiquitination was increased in visceral fat of obese pregnant women as compared to lean pregnant women. We further observed that insulin prevents, whereas ER stress and inflammation promote, adiponectin ubiquitination and degradation in differentiated 3T3-L1 adipocytes. CONCLUSION: We have identified adiponectin ubiquitination as a key mechanism by which obesity diminishes adiponectin secretion in pregnancy. This information will help us better understand the mechanisms controlling maternal insulin resistance and fetal growth in pregnancy and may provide a foundation for the development of strategies aimed at improving adiponectin production in pregnant women with obesity or gestational diabetes.

Characterization of the Primary Human Trophoblast Cell Secretome Using Stable Isotope Labeling With Amino Acids in Cell Culture.

The placental villus syncytiotrophoblast, the nutrient-transporting and hormone-producing epithelium of the human placenta, is a critical regulator of fetal development and maternal physiology. However, the identities of the proteins synthesized and secreted by primary human trophoblast (PHT) cells remain unknown. Stable Isotope Labeling with Amino Acids in Cell Culture followed by mass spectrometry analysis of the conditioned media was used to identify secreted proteins and obtain information about their relative rates of synthesis in syncytialized multinucleated PHT cells isolated from normal term placental villus tissue (n = 4/independent placenta). A total of 1,344 proteins were identified, most of which have not previously been reported to be secreted by the human placenta or trophoblast. The majority of secreted proteins are involved in energy and carbon metabolism, glycolysis, biosynthesis of amino acids, purine metabolism, and fatty acid degradation. Histone family proteins and mitochondrial proteins were among proteins with the slowest synthesis rate whereas proteins associated with signaling and the plasma membrane were synthesized rapidly. There was a significant overlap between the PHT secretome and proteins known be secreted to the fetal circulation by the human placenta in vivo. The generated data will guide future experiments to determine the function of individual secreted proteins and will help us better understand how the placenta controls maternal and fetal physiology.

Novel associations between parental and newborn cord blood metabolic profiles in the Norwegian Mother, Father and Child Cohort Study.

BACKGROUND: More than one third of Norwegian women and men between 20 and 40 years of age have elevated cholesterol concentration. Parental metabolic health around conception or during pregnancy may affect the offspring's cardiovascular disease risk. Lipids are important for fetal development, but the determinants of cord blood lipids have scarcely been studied. We therefore aimed to describe the associations between maternal and paternal peri-pregnancy lipid and metabolic profile and newborn cord blood lipid and metabolic profile. METHODS: This study is based on 710 mother-father-newborn trios from the Norwegian Mother, Father and Child Cohort Study (MoBa) and uses data from the Medical Birth Registry of Norway (MBRN). The sample included in this study consisted of parents with and without self-reported hypercholesterolemia the last 6 months before pregnancy and their partners and newborns. Sixty-four cord blood metabolites detected by nuclear magnetic resonance spectroscopy were analyzed by linear mixed model analyses. The false discovery rate procedure was used to correct for multiple testing. RESULTS: Among mothers with hypercholesterolemia, maternal and newborn plasma high-density lipoprotein cholesterol, apolipoprotein A1, linoleic acid, docosahexaenoic acid, alanine, glutamine, isoleucine, leucine, valine, creatinine, and particle concentration of medium high-density lipoprotein were significantly positively associated (0.001 ≤ q ≤ 0.09). Among mothers without hypercholesterolemia, maternal and newborn linoleic acid, valine, tyrosine, citrate, creatinine, high-density lipoprotein size, and particle concentration of small high-density lipoprotein were significantly positively associated (0.02 ≤ q ≤ 0.08). Among fathers with hypercholesterolemia, paternal and newborn ratio of apolipoprotein B to apolipoprotein A1 were significantly positively associated (q = 0.04). Among fathers without hypercholesterolemia, no significant associations were found between paternal and newborn metabolites. Sex differences were found for many cord blood lipids. CONCLUSIONS: Maternal and paternal metabolites and newborn sex were associated with several cord blood metabolites. This may potentially affect the offspring's long-term cardiovascular disease risk.

Mediators Linking Maternal Weight to Birthweight and Neonatal Fat Mass in Healthy Pregnancies.

CONTEXT: Lifestyle interventions have not efficaciously reduced complications caused by maternal weight on fetal growth, requiring insight into explanatory mediators. OBJECTIVE: We hypothesized that maternal mediators, including adiponectin, leptin, insulin, and glucose, mediate effects of pregestational BMI (pBMI) and gestational weight gain (GWG) on birthweight and neonatal fat mass percentage (FM%) through placental weight and fetal mediators, including insulin levels (Ifv) and venous-arterial glucose difference (ΔGfva). Hypothesized confounders were maternal age, gestational age, and parity. METHODS: A cross-sectional study of healthy mother-offspring-pairs (n = 165) applying the 4-vessel in vivo sampling method at Oslo University Hospital, Norway. We obtained pBMI, GWG, birthweight, and placental weight. FM% was available and calculated for a subcohort (n = 84). We measured circulating levels of adiponectin, leptin, glucose, and insulin and performed path analysis and traditional mediation analyses based on linear regression models. RESULTS: The total effect of pBMI and GWG on newborn size was estimated to be 30 g (range, 16-45 g) birthweight and 0.17 FM% (range, 0.04-0.29 FM%) per kg∙m-2 pBMI and 31 g (range, 18-44 g) and 0.24 FM% (range, 0.10-0.37 FM%) per kg GWG. The placental weight was the main mediator, mediating 25-g birthweight and 0.11 FM% per kg∙m-2 pBMI and 25-g birthweight and 0.13 FM% per kg GWG. The maternal mediators mediated a smaller part of the effect of pBMI (3.8-g birthweight and 0.023 FM% per kg∙m-2 pBMI) but not GWG. CONCLUSION: Placental weight was the main mediator linking pBMI and GWG to birthweight and FM%. The effect of pBMI, but not GWG, on birthweight and FM%, was also mediated via the maternal and fetal mediators.

The human placental proteome secreted into the maternal and fetal circulations in normal pregnancy based on 4-vessel sampling.

We sought to identify proteins secreted by the human placenta into the maternal and fetal circulations. Blood samples from the maternal radial artery and uterine vein and umbilical artery and vein were obtained during cesarean section in 35 healthy women with term pregnancy. Slow off-rate modified aptamer (SOMA) protein-binding technology was used to quantify 1310 known proteins. The uteroplacental and umbilical venoarterial concentration differences were calculated. Thirty-four proteins were significantly secreted by the placenta into the maternal circulation, including placental growth factor, growth/differentiation factor 15, and matrix metalloproteinase 12. There were 341 proteins significantly secreted by the placenta into the fetal circulation. Only 7 proteins were secreted into both the fetal and maternal circulations, suggesting a distinct directionality in placental protein release. We examined changes across gestation in the proteins found to be significantly secreted by the placenta into the maternal circulation using serial blood samples from healthy women. Among the 34 proteins secreted into the maternal circulation, 8 changed significantly across gestation. The identified profiles of secreted placental proteins will allow us to identify novel minimally invasive biomarkers for human placental function across gestation and discover previously unknown proteins secreted by the human placenta that regulate maternal physiology and fetal development.-Michelsen, T. M., Henriksen, T., Reinhold, D., Powell, T. L., Jansson, T. The human placental proteome secreted into the maternal and fetal circulations in normal pregnancy based on 4-vessel sampling.

Uteroplacental Glucose Uptake and Fetal Glucose Consumption: A Quantitative Study in Human Pregnancies.

Context: Maternal glucose levels and body mass index (BMI) are determinants of fetal overgrowth, but their relation to fetal glucose consumption is not well characterized in human pregnancy. Objectives: To quantify uteroplacental glucose uptake and the allocation of glucose between the placenta and fetus and to identify factors that affect fetal glucose consumption. Design: Human in vivo study in term pregnancies. Setting: Oslo University Hospital, Norway. Participants: One hundred seventy-nine healthy women with elective cesarean section. Interventions: Uterine and umbilical blood flow was determined using Doppler ultrasonography. Glucose and insulin were measured in the maternal radial artery and uterine vein and the umbilical artery and vein. In a subcohort (n = 33), GLUT1 expression was determined in isolated syncytiotrophoblast basal and microvillous plasma membranes. Main Outcome Measures: Uteroplacental glucose uptake and placental and fetal glucose consumption quantified by the Fick principle. Results: Median (Q1, Q3) uteroplacental glucose uptake was 117.1 (59.1, 224.9) µmol⋅min-1, and fetal and placental glucose consumptions were 28.9 (15.4, 41.8) µmol⋅min-1⋅kg fetus-1 and 51.4 (-65.8, 185.4) µmol⋅min-1⋅kg placenta-1, respectively. Fetal glucose consumption correlated with birth weight (ρ: 0.34; P < 0.001) and maternal-fetal glucose gradient (ρ: 0.60; P < 0.001), but not with maternal BMI or uteroplacental glucose uptake. Uteroplacental glucose uptake was correlated to placental glucose consumption (ρ: 0.77; P < 0.001). Fetal and placental glucose consumptions were inversely correlated (ρ: -0.47; P < 0.001), but neither was correlated with placental GLUT1 expression. Conclusion: These findings suggest that fetal glucose consumption is balanced against the placental needs for glucose and that placental glucose consumption is a key modulator of maternal-fetal glucose transfer in women.

Hormone Levels and Sexual Functioning After Risk-Reducing Salpingo-Oophorectomy.

INTRODUCTION: Women after risk-reducing salpingo-oophorectomy (RRSO) can have impaired sexual functioning, but whether there is an association between hormone levels and sexual functioning is unclear. AIM: To determine whether hormone levels are associated with sexual functioning in women after RRSO. METHODS: This is a retrospective cohort study of 198 sexually active and 91 inactive women after RRSO. Participants completed the Sexual Activity Questionnaire, questionnaires concerning hormone replacement therapy (HRT), quality of life, care from partner, body image, and comorbidity and provided blood samples. Associations between sexual functioning scores and covariates were examined by linear regression. Variables associated with sexual activity were examined by logistic regression. MAIN OUTCOME MEASURES: Associations with sexual pleasure and sexual discomfort scores were expressed by multivariable regression coefficients and associations with sexual activity were expressed by odds ratios. RESULTS: None of the hormone levels were associated with sexual pleasure in contrast to age (P = .032), current use of systemic HRT (P = .002), and more care form partner (P < .001). Increased free androgen index (P = .016), more care from partner (P = .017), systemic HRT (P = .002), and no history of cardiovascular disease (P = .001) were associated with less sexual discomfort. The odds ratio of being sexually active increased with younger age, no breast cancer, better quality of life, and more care from partner. CONCLUSIONS: Our results indicate that other factors than hormone levels are important for sexual functioning, although systemic HRT can have a positive impact on sexual functioning in women who have undergone RRSO. Testosterone therapy could improve women's sexual functioning after RRSO; however, the inverse association between free androgen levels and sexual discomfort should be addressed in future studies. Johansen N, Liavaag AH, Mørkird L, Michelsen TM. Hormone Levels and Sexual Functioning After Risk-Reducing Salpingo-Oophorectomy. Sex Med 2018;6:143-153.

The Effect of Pregnancy on the Long-term Risk of Graft Loss, Cardiovascular Disease, and Death in Kidney Transplanted Women in Norway: A Retrospective Cohort Study.

BACKGROUND: Kidney transplant recipients have now conceived for almost 50 years. Nevertheless, few studies have evaluated long-term health outcomes for kidney transplanted women after pregnancies. METHODS: We conducted a retrospective cohort study of all Norwegian women receiving a kidney transplant before the age of 50 years between 1969 and 2013, with graft loss, cardiovascular disease, and death as outcomes. Baseline characteristics for all women were ascertained at first transplantation, with information about exposure, outcomes, and potential confounders collected from medical records. To account for changes in pregnancy status, data were analyzed using proportional hazard Cox regression with pregnancy status as a time-dependent covariate changing at the time of pregnancy. RESULTS: Of 650 women studied, 124 had a pregnancy after kidney transplantation. During the study period, graft loss, cardiovascular disease, and death occurred in 237, 73, and 274 women, respectively. Pregnancy was associated with 54% lower risk of graft loss (95% confidence interval [CI]: 25% to 71%) and 72% lower risk of death (95% CI, 53%-84%). Adjusting for possible confounders had a minimal impact on estimated values. There were considerable uncertainties and no statistically significant results regarding the estimated risk of cardiovascular disease after pregnancy (univariate hazard ratio, 0.91; 95% CI, 0.43-1.92; multivariate hazard ratio, 0.71; 95% CI, 0.32-1.60). CONCLUSIONS: Kidney transplanted women with pregnancies have a low risk of subsequent graft loss or death. These results are reassuring for the current clinical practice.

The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo.

The human placenta is highly inaccessible for research while still in utero. The current understanding of human placental physiology in vivo is therefore largely based on animal studies, despite the high diversity among species in placental anatomy, hemodynamics and duration of the pregnancy. The vast majority of human placenta studies are ex vivo perfusion studies or in vitro trophoblast studies. Although in vitro studies and animal models are essential, extrapolation of the results from such studies to the human placenta in vivo is uncertain. We aimed to study human placenta physiology in vivo at term, and present a detailed protocol of the method. Exploiting the intraabdominal access to the uterine vein just before the uterine incision during planned cesarean section, we collect blood samples from the incoming and outgoing vessels on the maternal and fetal sides of the placenta. When combining concentration measurements from blood samples with volume blood flow measurements, we are able to quantify placental and fetal uptake and release of any compound. Furthermore, placental tissue samples from the same mother-fetus pairs can provide measurements of transporter density and activity and other aspects of placental functions in vivo. Through this integrative use of the 4-vessel sampling method we are able to test some of the current concepts of placental nutrient transfer and metabolism in vivo, both in normal and pathological pregnancies. Furthermore, this method enables the identification of substances secreted by the placenta to the maternal circulation, which could be an important contribution to the search for biomarkers of placenta dysfunction.

Transplacental nutrient transfer in the human in vivo determined by 4 vessel sampling.

BACKGROUND: The intrauterine environment and especially the fetal nutritional conditions affect lifelong health. There are few human in vivo studies on fetal nutrition. The importance to test experimentally based concepts of fetal nutrition in a human in vivo setting is becoming increasingly apparent. A way of testing nutrient transfer in human is 4-vessel sampling, which implies blood sampling from artery and vein on both sides of the placenta. Here we give a brief review of the studies using the 4-vessel sampling method. METHOD: We performed systematic searches in Ovid MEDLINE and EMBASE (Ovid) from 1946 to May 2016. The following search terms were used to identify eligible articles: [placenta] AND [glucose/blood glucose] OR [amino acids] OR [lipids] OR [cholesterol] OR [nutrient] AND [blood sample] OR [biological transport] OR [transport/transfer/exchange] OR [maternal-fetal exchange] AND [humans]. RESULTS: The search retrieved 623 studies. After abstract scanning 25 full text articles were evaluated and seven articles describing 4-vessel sampling were identified. The studies had from 14 to 77 participants and reported placental transfer of different nutrients (glucose, lactate, amino acids and arachidonic acid). CONCLUSION: Few studies have used 4 vessel sampling to study placental nutrient transfer in human pregnancies. Overall these studies indicate that the transfer of nutrients between the mother and the fetus is highly "dynamic," i.e. most nutrients may pass either way on both the maternal and fetal sides of the placenta. Furthermore, the concept that the placenta is a metabolically highly active organ affecting transfer of glucose, amino acids and lipids, fits the human in vivo data. The 4-vessel method can provide essential information on the transfer between the mother, placenta and fetus of virtually any compound.