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, birth weight, and placental glucose metabolism: Evidence for a role of placental hexokinase

BACKGROUND

The principal fetal energy source is glucose provided by 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.

OBJECTIVES

To test the hypothesis that placental hexokinase activity is related to maternal body mass index, placental glucose uptake and consumption, and birth weight.

STUDY DESIGN

Sixty-seven healthy pregnant participants at term were included in this study at Oslo University Hospital, 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 arterio-venous 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 uptake. Spearman's rank correlation was performed for statistical analyses to study the correlation of placental hexokinase activity (mU/mg protein) with prepregnancy body mass index, maternal glucose and insulin, birth weight, uteroplacental glucose uptake and consumption, and fetal glucose uptake (μmol/min). 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. Mean (SD) activity was 19.6 (4.64) mU/mg of protein. Placental hexokinase activity correlated positively with prepregnancy body mass index (Spearman's rho (ρ)=0.33; P=0.006). Upon controlling for hours of fasting, hexokinase activity showed positive correlations with both maternal glucose (r=0.30; P=0.01) and insulin (r=0.28; P=0.02). Hexokinase activity was positively correlated with uteroplacental glucose uptake (ρ=0.31; P=0.01) and consumption (ρ=0.28; P=0.02). Hexokinase activity did not correlate with fetal glucose uptake. Upon controlling for placental weight, hexokinase activity showed a positive correlation with birth weight (r=0.31; P=0.01).

CONCLUSION

Our findings suggest that placental hexokinase, being crucial for uteroplacental retention of glucose for own disposition, is related to both maternal body mass index and birth weight 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.

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.

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 ≤ P_interaction ≤ 0.04). Paternal TC level was not associated with change in offspring body weight (0.17 ≤ P_interaction ≤ 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 ≤ P_interaction ≤ 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 ≤ P_interaction ≤ 0.03). Parental metabolites were not associated with change in offspring height or body mass index up to 8 years of age (0.07 ≤ P_interaction ≤ 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.

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.

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.

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.

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.

Does prolonged labor affect the birth experience and subsequent wish for cesarean section among first-time mothers? A quantitative and qualitative analysis of a survey from Norway

Background

Prolonged labor might contribute to a negative birth experience and influence first-time mothers’ attitudes towards future pregnancies. Previous studies have not adjusted for possible confounding factors, such as operative delivery, induction and postpartum hemorrhage. We aimed to determine the impact of prolonged labor on birth experience and a wish for cesarean section in subsequent pregnancies.

Methods

A survey including the validated “Childbirth Experience Questionnaire”. First-time mothers giving birth between 2012 and 2014 at a Norwegian university hospital participated. Data from deliveries were collected. Regression analysis and thematic content analysis were performed.

Results

459 (71%) women responded. Women with labor duration > 12 h had significantly lower scores on two out of four sub-items of the questionnaire: own capacity (p = 0.040) and perceived safety (p = 0.023).

Other factors contributing to a negative experience were:

Cesarean section vs vaginal birth: own capacity (p = 0.001) and perceived safety (p = 0.007). Operative vaginal vs spontaneous birth: own capacity (p = 0.001), perceived safety (p < 0.001) and participation (p = 0.047).

Induced vs spontaneous start: own capacity (p = 0.039) and participation (p = 0.050). Postpartum hemorrhage ≥500 ml vs < 500 ml: perceived safety (p = 0.002) and participation (p = 0.031).

In the unadjusted analysis, prolonged labor more than doubled the risk (odds ratio (OR) 2.66, 95%CI 1.42–4.99) of a subsequent wish for cesarean delivery. However, when adjustments were made for mode of delivery and induction, emergency cesarean section (OR 8.86,95%CI 3.85–20.41) and operative vaginal delivery (OR 3.05, 95%CI 1.46–6.38) remained the only factors significantly increasing the probability of wanting a cesarean section in subsequent pregnancies.

The written comments on prolonged labor (n = 46) indicated four main themes:

Difficulties gaining access to the labor ward.

Being left alone during the unexpectedly long, painful early stage of labor.

Stressful operative deliveries and worse pain than imagined.

Lack of support and too little or contradictory information from the staff.

Conclusions

Women with prolonged labors are at risk of a negative birth experience. Prolonged labor per se did not predict a wish for a cesarean section in a subsequent pregnancy. However, women with long labors more often experience operative delivery, which is a risk factor of a later wish for a cesarean section.

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.

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.

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.

De-medicalization of birth by reducing the use of oxytocin for augmentation among first-time mothers - a prospective intervention study

BACKGROUND

The use of synthetic oxytocin for augmentation of labor is rapidly increasing worldwide. Hyper-stimulation is the most significant side effect, which may cause fetal distress and operative delivery. We performed an intervention consisting of an educational program and modified guidelines to achieve a more appropriate use of oxytocin.

METHODS

This prospective intervention study included 431 first-time mothers at term with spontaneous onset of labor before (October 2012 to May 2013), and 664 after the intervention (April 2014 to April 2015). Our outcomes were prevalence and duration of oxytocin treatment, mode of delivery, indication for operative delivery, episiotomy, anal sphincter tears, bleeding, labor duration, pain relief and the effect of oxytocin on mode of delivery.

RESULTS

After the intervention, 52.9% were diagnosed with dystocia, compared with 68.9% before (p < 0.001). Oxytocin was not always used in accordance with the guidelines, but a significant reduction in oxytocin rates from 63.3% to 54.1% (p < 0.001) was obtained. More women without dystocia according to the existing guidelines were augmented after the intervention (18.9% vs 8.4%, p < 0.001). Assessing all labors, the median duration of oxytocin treatment was reduced by 72% (from 90 to 25 min) without increasing the median duration of labor (385 min in both groups). There was a moderate reduction in operative vaginal deliveries from 26.9 to 21.5% (p = 0.04), and dystocia as an indication for these deliveries increased (p = 0.01). There was a moderate increase in caesarean sections from 6.7 to 10.2% (p = 0.05), but no increase in dystocia as an indication for these deliveries. Women receiving oxytocin were more likely to have an operative vaginal birth, even after adjusting for birth weight, epidural analgesia and labor duration, OR: 2.1 (CI 1.1-4.0) before and OR 2.7 (CI 1.6-4.5) after the intervention.

CONCLUSIONS

Our intervention led to a significant reduction in the use of oxytocin. However, more than half of the women remained diagnosed with dystocia. Operative vaginal births seem to be associated with oxytocin treatment. Therefore, augmentation with oxytocin should be used with caution and only when medically indicated. Even more modified guidelines for augmentation than the ones applied in this study might be appropriate.

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.

Use of hormone replacement therapy after risk-reducing salpingo-oophorectomy

INTRODUCTION

After premenopausal risk-reducing salpingo-oophorectomy (RRSO) to prevent ovarian cancer, the non-cancer-related morbidity and mortality may be increased if sex hormones are not replaced. Several guidelines recommend systemic hormone replacement therapy (HRT) to these women until the expected age of menopause. We aimed to study the use of HRT after RRSO.

MATERIAL AND METHODS

Participants were 324 women after RRSO and 11 160 postmenopausal controls. A subsample of 950 controls had undergone bilateral salpingo-oophorectomy (BSO). All participants completed the same questionnaire regarding HRT use. We compared HRT use in the RRSO group with the BSO controls using logistic regression.

RESULTS

Among the women aged ≤52 years without a history of breast cancer, 51.7% of the RRSO group and 48.7% of the BSO controls reported current use of systemic HRT (odds ratio 1.13, 95% confidence interval 0.72-1.76). Among the HRT users, systemic estrogen was used by 35.1% and 58.7% in the RRSO and BSO control groups, respectively (p = 0.001). Among the women aged >52 years, 16.8% of the RRSO group and 38.4% of the BSO controls (p < 0.001) used systemic HRT.

CONCLUSIONS

Among the RRSO women and BSO controls ≤52 years old without a history of breast cancer, relatively few were current users. If there are no contraindications, these women would benefit from systemic HRT. Additionally, almost 40% of the BSO controls >52 years used systemic HRT. Doctors should be aware of this practice and prescribe systemic HRT when indicated.

In vivo uteroplacental release of placental growth factor and soluble Fms-like tyrosine kinase-1 in normal and preeclamptic pregnancies

BACKGROUND

Preeclampsia is characterized by maternal endothelial dysfunction, which underlies a highly diverse clinical presentation. The pathophysiologic condition remains to be unraveled fully, but interplay between factors that are released from the placenta and maternal vascular vulnerability is likely. An imbalance in circulating angiogenic factors is a prominent feature of preeclampsia; placental growth factor and soluble Fms-like tyrosine kinase 1 have been implemented as biomarkers of placental function and preeclampsia. Their test accuracies are limited in a clinical setting, which urges better insight into their production and removal. Current data suggest that placental growth factor and soluble Fms-like tyrosine kinase 1 are released from the placenta. Both the circulating levels and the placental expression are altered in preeclamptic pregnancies. However, in vivo placental release has not been determined in human pregnancies. Moreover, there is evidence that extra-placental tissues might contribute to the circulating levels placental growth factor and soluble Fms-like tyrosine kinase 1 in normal and preeclamptic pregnancies.

OBJECTIVES

We aimed to study the in vivo placental release of placental growth factor and soluble Fms-like tyrosine kinase 1 by determining the uteroplacental arteriovenous differences in human pregnancies. Further, we investigated whether this release was altered in early-onset preeclampsia compared with control subjects and whether there was a release of placental growth factor and soluble Fms-like tyrosine kinase 1 from maternal systemic endothelium.

STUDY DESIGN

We conducted a case-control study at Oslo University Hospital and included 23 women with preeclampsia (diagnosis <34 weeks) and 20 control subjects. During cesarean delivery, we sampled blood from 3 vessels simultaneously (uterine vein, radial artery, and antecubital vein). We determined concentrations of placental growth factor and soluble Fms-like tyrosine kinase 1 and calculated the arteriovenous differences. A possible net placental and extra-placental release was evaluated with the use of a Wilcoxon signed rank test. Differences between groups were compared by a Mann-Whitney U-test.

RESULTS

The median gestational age at delivery was 33.4 weeks (Q1, 28.3; Q3, 34.4 weeks) in the preeclamptic group and 39.3 weeks (Q1, 39.0; Q3, 39.6 weeks) in the control subjects. Women with preeclampsia had lower plasma concentrations of placental growth factor and higher concentrations of soluble Fms-like tyrosine kinase 1 compared with control subjects (P<.001). There were significant uteroplacental arteriovenous differences of soluble Fms-like tyrosine kinase 1 in preeclampsia (P<.001), but not in the control subjects. The uteroplacental arteriovenous differences of placental growth factor were significant in both groups (P<.001). Despite lower concentrations of plasma placental growth factor in women with preeclampsia, the arteriovenous differences were not significantly different from normal pregnancies (P=.53), even when we corrected for placental weight (P=.79). We found no placental growth factor or soluble Fms-like tyrosine kinase 1 concentration differences between the radial artery and the antecubital vein.

CONCLUSION

Our findings are consistent with a net release of soluble Fms-like tyrosine kinase 1 from the placenta in early-onset preeclampsia. This study demonstrated a placental release of placental growth factor to the maternal circulation but could not demonstrate that this release was impaired in the preeclamptic group. We could not find evidence of systemic endothelial release of placental growth factor and soluble Fms-like tyrosine kinase 1 by analyzing the arteriovenous differences in the forearm. This study contributes to the pathophysiologic understanding of preeclampsia by the use of the clinical setting to test current concepts in vivo and underscores that studies of in vivo degradation rates of placentally released compounds are needed.

Pregnancy outcomes following maternal kidney transplantation: a national cohort study

INTRODUCTION

Internal design flaws in previous reports of pregnancies following kidney transplantation have been outlined, and the need for a validation has been stated. The aim of this study was to collect information about obstetrical and neonatal outcomes in all Norwegian pregnancies following maternal kidney transplantation, and to compare these data with the general Norwegian population.

MATERIAL AND METHODS

A retrospective cohort study based on 1 272 000 deliveries in Norway between 1969 and 2013. All data were collected from medical records. From the source population, we compared 119 first deliveries in kidney transplanted women with 238 first deliveries in nontransplanted women. An explanatory strategy was used in the analysis.

RESULTS

The risk of preeclampsia was significantly increased in kidney-transplanted women compared with nontransplanted women (adjusted incidence rate ratio: 6.06, 95% confidence interval 3.18-11.55). Additionally, preeclampsia in kidney-transplanted women was early onset (diagnosed <34 gestational weeks) in half of the cases. There were also persistent risks of cesarean delivery (adjusted incidence rate ratio 4.14, 95% confidence interval 2.56-6.66), preterm delivery (adjusted incidence rate ratio 4.45, 95% confidence interval 2.13-9.30) and a birthweight below the 10th centile (22.7% vs. 9.7%) in the kidney-transplanted group. A high proportion (63%) of the kidney-transplanted women with chronic hypertension developed preeclampsia.

CONCLUSIONS

Using consistent diagnostic criteria, this study shows high rates of maternal and neonatal complications in pregnancies following kidney transplantation. In particular, we reveal a high rate of early-onset preeclampsia requiring operative preterm delivery, conferring long-term risks on both the mother and child.

Sexuality and fertility in women with Addison's disease

CONTEXT

Females with primary adrenal insufficiency (Addison's disease) have reduced levels of circulating androgens, which are allegedly important for sexual functioning.

OBJECTIVE

The aim was to determine peripheral androgen status, sexual functioning, and birth rates in Addison's disease females.

DESIGN

In a postal survey, all 269 females in the Norwegian Addison's registry were invited to complete the Sexual Activity Questionnaire (SAQ) and registration of childbirths. Blood samples were analyzed for 5alpha-androstane-3alpha,17beta-diol-3-glucuronide (3alpha-Diol-G) and compared with blood donor levels. The SAQ scores were compared with 740 age-matched controls from the general population and 234 women subjected to risk-reducing salpingo-oophorectomy. Fertility was estimated as standardized incidence ratio for birth; the expected number of births was estimated from population statistics.

RESULTS

The SAQ was completed by 174 (65%) of the Addison's patients. Those not taking DHEA had significantly lower 3alpha-Diol-G levels than blood donors (mean, 0.53 vs. 2.2 ng/ml; P < 0.0001), whereas those on DHEA treatment had elevated levels (mean, 5.8 vs. 2.2 ng/ml; P = 0.002). The Addison's disease females were equally sexually active as the controls, but they reported significantly higher pleasure and less discomfort. They reported lower pleasure but less discomfort than the risk-reducing salpingo-oophorectomy women. The fertility was significantly reduced in females with Addison's disease; 54 children were born to mothers with established diagnosis (87.5 expected), yielding a standardized incidence ratio for birth of 0.69 (confidence interval, 0.52-0.86).

CONCLUSION

Despite androgen depletion, females with Addison's disease do not report impaired sexuality. The fertility is reduced after the diagnosis is made; the reasons for this remain unknown.

Fatigue and Quality of Life After Risk-Reducing Salpingo-Oophorectomy in Women at Increased Risk for Hereditary Breast-Ovarian Cancer

Background:

Risk-reducing salpingo-oophorectomy (RRSO) is the safest intervention for prevention of ovarian cancer in women at increased risk for hereditary breast-ovarian cancer. Little is known about other effects of RRSO. The objective of this study was to investigate quality of life (QoL) and fatigue in a sample of women who had RRSO for increased cancer risk and to compare the findings with those of age-matched controls from the general population (NORM).

Materials and Methods:

In a cross-sectional follow-up mailed questionnaire design, 301 (67%) of 450 invited Norwegian women with RRSO attended. The questionnaire contained measures of QoL, fatigue, anxiety/depression, and body image, and questions about demography, lifestyle, and morbidity. The findings were compared with those of the NORM.

Results:

For RRSO women, mean age at survey was 53.7 years (SD, 9.2), mean age at RRSO was 48.4 years (SD 8.4), and median follow-up time was 5.0 years (range, 1-15 years). No clinically significant differences were observed between RRSO and NORM for any of the QoL or fatigue dimensions. In subgroup analyses of the RRSO group, no clinically significant differences in QoL and fatigue were observed between those who had surgery before or after age 50 years, or between BRCA1/2 carriers and women with unknown mutation statuses. Women who had cancer (32%), however, showed clinically significant lower levels of QoL and more fatigue than women without cancer.

Conclusions:

Women who had RRSO showed similar levels of QoL and fatigue as NORM. Women who had cancer before RRSO had lower levels of QoL and more fatigue.

A controlled study of mental distress and somatic complaints after risk-reducing salpingo-oophorectomy in women at risk for hereditary breast ovarian cancer

OBJECTIVES

Risk-reducing salpingo-oophorectomy (RRSO) provides effective protection against ovarian cancer in BRCA mutation carriers and in women at risk for hereditary breast ovarian cancer, but little is known about non-oncologic morbidity after the procedure. We explored mental distress and somatic complaints in women after RRSO compared to controls from the general population.

METHODS

503 women from hereditary breast ovarian cancer families who had undergone RRSO after genetic counseling received a mailed questionnaire. 361 (71%) responded and 338 (67%) delivered complete data (cases). Controls were five randomly allocated age-matched controls per case (N=1690) from the population-based Norwegian Nord-Trøndelag Health Study (HUNT-2).

RESULTS

Mean age of cases and controls was 54.6 years at survey. Mean time since surgery was 5.3 years (median 6.0). Compared to controls, the RRSO group had more palpitations (p=0.02), constipation (p=0.01), pain and stiffness (p=0.02), osteoporosis (p=0.02) and musculoskeletal disease (p=0.01) even after adjustments for demographic factors including use of hormonal replacement therapy. The RRSO group had lower levels of depression (p<0.001) and total mental distress (p=0.002) compared to controls. In multivariate linear regression analyses, RRSO was associated with lower levels of depression (p<0.001) and total mental distress (p=0.002).

CONCLUSIONS

In this controlled observational study, we found more somatic morbidity such as osteoporosis, palpitations, constipation, musculoskeletal disease and pain and stiffness but lower levels of mental distress among women who had undergone RRSO compared to controls.

Metabolic syndrome after risk-reducing salpingo-oophorectomy in women at high risk for hereditary breast ovarian cancer: a controlled observational study

Surgical menopause may increase the risk of cardiovascular diseases (CVDs). The aim of this study was to determine the risk of metabolic syndrome in women who had undergone risk-reducing salpingo-oophorectomy (RRSO) because of increased risk of hereditary breast ovarian cancer (HBOC). A sample of 326 (65% of invited) women at risk of HBOC who had undergone RRSO was compared to 679 women from the general population. Mean follow-up after surgery was 6.5 years (standard deviations [SD] 4.4). RRSO was significantly associated with metabolic syndrome according to the 2005 National Cholesterol Education Program Adult Treatment Panel III criteria (odds ratio [OR] 2.46 [95% confidence interval (CI) 1.63, 3.73]) and according to the International Diabetes Federation criteria (OR 2.49 [CI 1.60, 3.88]), as were increasing age and body mass index (BMI). RRSO in women at risk of HBOC is significantly associated with the metabolic syndrome, and the follow-up after RRSO should take these findings into consideration.