21 research outputs found

    Blood pressure during pregnancy, neonatal size and altered body composition: The Healthy Start study

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    Objective: The objective of this study is to estimate associations between changes in maternal arterial pressure during normotensive pregnancies and offspring birth weight and body composition at birth. Study Design: Prospective study of 762 pregnant normotensive Colorado women, recruited from outpatient obstetrics clinics. Repeated arterial pressure measurements during pregnancy were averaged within the second and third trimesters, respectively. Multivariable regression models estimated associations between second to third trimester changes in arterial pressure and small-for-gestational-age birth weight, fat mass, fat-free mass and percent body fat. Results: A greater second to third trimester increase in maternal arterial pressure was associated with greater odds of small-for-gestational-age birth weight. Greater increases in maternal diastolic blood pressure were associated with reductions in offspring percent body fat (-1.1% in highest vs lowest quartile of increase, 95% confidence interval: -1.9%, -0.3%). Conclusion: Mid-to-late pregnancy increases in maternal arterial pressure, which do not meet clinical thresholds for hypertension are associated with neonatal body size and composition

    Transplacental Supply of Mannose and Inositol in Uncomplicated Pregnancies Using Stable Isotopes

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    OBJECTIVE: The aim of this study was to determine relative contributions of transplacental flux vs. fetal production for inositol and mannose in normal term pregnancies. STUDY DESIGN: Seven term uncomplicated pregnancies undergoing cesarean section were infused with (13)C- and (2)H-labeled isotopes of glucose, inositol, and mannose until a steady state was achieved. Maternal and fetal concentrations of labeled and unlabeled glucose, mannose, and inositol were measured using gas chromatography/mass spectroscopy. The fetomaternal molar percentage excess ratio was calculated for each glucose, mannose, and inositol. RESULTS: The fetomaternal molar percentage excess ratio of mannose in the fetal artery (F(artery)/M) was 0.99 [97.5% confidence interval (CI), 0.91-1.07] and in the fetal vein (F(vein)/M), 1.02 (97.5% CI, 0.95-1.10). Both were not significantly different from 1.0, consistent with transplacental supply. The fetomaternal ratios for glucose were similar to mannose (fetal artery, 0.95; 97.5% CI, 0.84-1.15; and fetal vein, 0.96; 97.5% CI, 0.85-1.07). The fetomaternal ratio for inositol was significantly less than 1.0 (fetal artery, 0.08; 97.5% CI, 0.05-0.12; fetal vein, 0.12; 97.5% CI, 0.06-0.18), indicating little transplacental flux and significant fetal production. CONCLUSION: In normal term pregnancies, fetal mannose and glucose concentrations are dependent upon maternal transplacental supply. Fetal inositol is not dependent upon transplacental supply

    Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

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    BACKGROUND: Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. METHODS: The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. FINDINGS: Globally, 18·7% (95% uncertainty interval 18·4–19·0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58·8% (58·2–59·3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48·1 years (46·5–49·6) to 70·5 years (70·1–70·8) for men and from 52·9 years (51·7–54·0) to 75·6 years (75·3–75·9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49·1 years (46·5–51·7) for men in the Central African Republic to 87·6 years (86·9–88·1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216·0 deaths (196·3–238·1) per 1000 livebirths in 1950 to 38·9 deaths (35·6–42·83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5·4 million (5·2–5·6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult males, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. INTERPRETATION: This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing

    Intrauterine growth restriction (IUGR): biometric and doppler assessment

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    Intrauterine growth restriction (IUGR) is a common complication in pregnancy and influences morbidity and mortality at all stages of life. Historically, the management of IUGR has been dependent on antenatal biophysical testing and umbilical artery Doppler studies. With recent Doppler studies of the fetal central circulation, including intracardiac flows and the ductus venosus, better timing of delivery to minimize morbidity may be possible. This review will provide the reader with tools to diagnose IUGR, more accurately date the IUGR pregnancy with poor dating criteria, and better assess the condition of the IUGR fetus. A brief review of animal models of IUGR is presented to demonstrate research directions for answering human clinical questions and potentially carrying therapeutic intervention from the bench to the bedside

    The transplacental transport of essential amino acids in uncomplicated human pregnancies

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    Objective: The purpose of this study was to assess the placental transport of the essential amino acids (EAAs) in normal pregnancies. Study Design: Nine ( 13C or 2H) EAAs were infused simultaneously as a bolus into the maternal circulation of 12 patients with uncomplicated pregnancy before cesarean delivery. Maternal samples were collected before and after the bolus; umbilical blood was collected at delivery. The fetal/maternal molar percent enrichment for each EAA was calculated for both the umbilical vein and artery. Plasma amino acids enrichments were analyzed by gas chromatography mass spectrometry and concentrations by high performance liquid chromatography. Data were analyzed with paired and unpaired t-test. Results: The umbilical arterial enrichments were significantly lower than the venous. Fetal/maternal ratios for leucine, isoleucine, methionine, and phenylalanine were > 0.80, with no significant differences among their molar percent enrichment ratios, whereas fetal/maternal ratios of the other 5 EAAs were significantly lower (< 0.60). Conclusion: The EAAs showed significant umbilical uptake and striking differences in their transport rates in vivo

    Differences in fat and lean mass proportions in normal and growth-restricted fetuses

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    The purpose of this study was to assess fetal subcutaneous fat and lean mass areas as predictors of fetal growth restriction. Seventeen severe fetal growth-restricted (abdominal circumference, <2 SD) fetuses and 20 control fetuses underwent ultrasound measurements of subcutaneous fat, lean mass, and standard biometry. Thigh subcutaneous fat and lean mass were measured on enlarged ultrasound axial images (subcutaneous fat area = total cross sectional area - lean mass area [bone + muscle areas]). Subcutaneous fat and lean mass areas were expressed as a percentage of the total cross-sectional area and were normalized to femur length and head circumference. Measurements were modeled as a function of fetal growth-restriction status and week of gestation with multiple linear regression. Fetal growth-restriction fetuses showed reductions in fat and lean mass (in standard biometry) and showed a disproportionate reduction in fat mass compared with lean mass. These were all associated significantly with fetal growth restriction. Fetal growth-restricted fetuses have reduced subcutaneous fat and lean mass compared with control fetuses; a further reduction occurs in subcutaneous fat concentration compared with the reduction in lean mass when fat is normalized for body size, with either head circumference or femur length. Fat-to-bone proportions may be useful in distinguishing the small for gestational age fetus who is truly fetal growth restriction from the constitutionally small fetus

    Small size-specific umbilical vein diameter in severe growth restricted fetuses that die in utero

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    Background: To study changes in umbilical vein (UV) blood flow velocity, diameter and blood flow volume in intrauterine growth retardation (IUGR) fetuses who die in utero (IUD-IUGR). Methods: Twelve singleton IUGR fetuses who died in utero below 600 g were included. All cases had abnormal uterine and umbilical arteries PI. UV diameter and velocity were measured at the time of diagnosis, and at the last exam, within 24 hours prior to intrauterine death. UV flow was calculated per unit weight (mL/min/kg) and abdominal circumference (AC) (mL/min/cm). UV diameter and velocity were normalized per unit AC. Findings were compared to 14 severe viable-IUGR and 22 normal gestational age-matched fetuses. Results: UV flow (mL/min/kg) was significantly lower in IUD-IUGR compared to viable-IUGR (87 \ub1 30 mL/min/kg) and control fetuses (131 \ub1 33 mL/min/kg) both at the first (79 \ub1 40 mL/min/kg) (P < 0.0001), and at the last exam (54 \ub1 29 mL/min/kg) (P < 0.0001). No significant longitudinal flow changes were observed. UV velocity/AC was significantly reduced both in IUD-IUGR and viable-IUGR compared to normal fetuses. UV diameter/AC, was significantly reduced only in IUD-IUGR and not in viable-IUGR compared to normal fetuses. Conclusions UV flow (mL/min/kg) was significantly lower in IUD-IUGR fetuses both versus viable-IUGR and normal fetuses. A low flow was due to a decreased UV flow velocity, but also due to a reduced vessel size. This significantly smaller UV size observed in IUGR fetuses with the worst outcome could be considered a severe prognostic sign because of the diagnosis of severe growth restriction. Copyrigh

    Relationship of fetal growth to duration of heat stress in an ovine model of placental insufficiency

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    Objective: Intrauterine growth restriction in an ovine model occurs after exposure to environmental heat stress for 80 days beginning at 35 days\u2019 gestation. Our objective was to determine whether intrauterine growth restriction is reversible on removal of the heat stress after only 55 days of exposure; that is, does a brief exposure at a critical point of development suffice? Study Design: Five pregnant ewes were exposed to heat stress beginning at 35 days\u2019 gestation and were removed after 55 days of exposure. Five ewes in a control group were studied as contemporaneous controls and added to data from 37 ewes in a control group previously studied. Serial fetal biometric ultrasonographic measurements (biparietal diameter, abdominal circumference, femur length, and tibia length) were obtained beginning at 50 days\u2019 gestation. Growth curves were calculated for each parameter, and comparisons were made between fetuses in the group exposed to heat stress for 55 days and 42 fetuses in the control group and 4 fetuses from a previous study that were exposed to heat for 80 days. Regression lines, 95% confidence intervals, and slopes were determined for each study group. Results: Both the 55-day and the 80-day heat exposure groups showed a significant reduction in fetal and placental weights compared with the control group. Animals in the 80-day group had significantly lower fetal and placental weights than the animals in the 55-day group (P < .05). Indexes of somatic growth (abdominal circumference, femur length, and tibia length) for the control group were significantly greater than those of either the 55-day group or the 80-day group (P < .001). Asymmetric growth restriction was evident in both heat groups by a biparietal diameter/abdominal circumference ratio that was significantly higher than in the control group (P < .004 for the 55-day group and P < .001 for the 80-day group). The slopes for somatic parameters (abdominal circumference, femur length, and tibia length) versus time became significantly different between the control and 55-day groups at 77, 101, and 80 days\u2019 gestation, respectively. The 55-day group had abdominal circumference and femur length measurements that were significantly greater than those in the 80-day group. Conclusion: The fetuses in the 55-day and 80-day groups reflect a pattern of asymmetric intrauterine growth restriction. Our findings suggest that the initial insult affecting fetal and placental growth occurs early in gestation, but removal of fetuses after only 55 days of exposure significantly reduces the degree of fetal growth restriction compared with that found in those fetuses exposed for 80 days
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