Obstetric problems in diabetic pregnancy - The role of fetal hypoxia

Meta-analysis of a family history of diabetes in schizophrenia

OBJECTIVE

Type 2 diabetes (T2DM) is common in patients with schizophrenia and non-affective psychosis. These patients also have an increased prevalence of a family history of T2DM. We performed a systematic review and meta-analysis of the association between a family history of T2DM and schizophrenia.

METHOD

We searched electronic databases from inception until July 2022 for studies of a family history of T2DM or gestational diabetes in patients with schizophrenia and controls. We performed random effects meta-analysis, calculating odds ratios (ORs) and 95 % confidence intervals (CI) and meta-regression analyses.

RESULTS

Nine studies were included, comprising 2953 patients with non-affective psychosis and 4484 controls. Schizophrenia was associated with an over two-fold increased odds of a family history of T2DM or gestational diabetes (OR = 2.18, 95 % CI 1.61-2.96, p < 0.01). In meta-regression analyses, age, sex, study quality score, and year of publication were all unrelated to the association.

CONCLUSION

We found that patients with schizophrenia had a 2.2-fold increased odds of a family history of T2DM versus controls. This association may be relevant to both the pathophysiology of schizophrenia and the reported increased risk of development of diabetes with antipsychotic treatment.

Fetoplacental oxygen homeostasis in pregnancies with maternal diabetes mellitus and obesity

Despite improvements in clinical management, pregnancies complicated by pre-existing diabetes mellitus, gestational diabetes mellitus or obesity carry substantial risks for parent and offspring. Some of the endocrine and metabolic changes in parent and fetus in diabetes mellitus and obesity lead to fetal oxygen deficit, mostly due to insulin-induced accelerated fetal metabolism. The human fetus deals with reduced oxygenation through a wide range of adaptive responses that act at various levels in the placenta as well as the fetus. These responses ensure adequate oxygen delivery to the fetus, increase the oxygen transport capacity of fetal blood and redistribute oxygen-rich blood to vital organs such as the brain and heart. The liver has a central role in adapting to reduced oxygenation by increasing its oxygen extraction and stimulating erythropoietin synthesis to increase haematocrit. The type of adaptive response depends on the onset and duration of hypoxia and the severity of the metabolic disturbance. In pregnancies characterized by diabetes mellitus or obesity, these adaptive systems come under additional strain owing to the increased maternal supply of glucose and resultant fetal hyperinsulinaemia, both of which stimulate oxidative metabolism. In the rare situation that the adaptive responses are overwhelmed, stillbirth can ensue.

Evaluation of the selected parameters of the fetal diastolic functions in normally grown or macrosomic fetuses of gestational diabetic mothers with poor glycaemic control

OBJECTIVE

This study aimed to investigate whether the third trimester fetal cardiac diastolic function measured by selected conventional Doppler indices is affected in appropriate-for-gestational-age or macrosomic fetuses of gestational diabetic mothers with poor glycaemic control.

METHODS

This cross-sectional study included 93 pregnant women divided into two groups. Group 1 included 45 appropriate-for-gestational-age or macrosomic fetuses from gestational diabetic mothers with poor glycaemic control (study group). Group 2 included 48 appropriate-for-gestational-age fetuses from gestational age-matched healthy mothers (control group). Functional fetal cardiac parameters and fetoplacental Doppler parameters were measured. Data were compared between the two groups.

RESULTS

Maternal characteristics did not differ significantly between the study and the control group. There were no significant differences in the early and late velocity, early/late velocity ratio of both mitral and tricuspid valves, the fetal pulmonary vein pulsatility index, and the ductus venosus pulsatility index between the study and the control group. Moreover, the rate of abnormal Doppler findings in pulmonary vein (pulmonary vein pulsatility index >95th centile), ductus venosus (ductus venosus pulsatility index >95th centile), and peripheral vessels (umbilical artery pulsatility index >95th centile, middle cerebral artery pulsatility index <5th centile, cerebra-placental index >95th centile) were comparable in both groups.

CONCLUSIONS

The third trimester fetal diastolic functions measured by selected conventional Doppler techniques do not seem to be altered in appropriate-for-gestational-age or macrosomic fetuses of gestational diabetic mothers who have poor glycaemic control.

Evaluation of fetal cardiac functions in the setting of maternal diabetes: Application of the global spherical index, global strain and fractional area change by the speckle tracking technique

OBJECTIVE

To evaluate ventricular contractility and profile heart deformations in fetuses of hyperglycemic mothers using the Speckle tracking imaging (STI). The fractional area change (FAC), global longitudinal strain (GLS) and global sphericity index (GSI) of the 4-chamber view (4-CV) were computed.

STUDY DESIGN

Dynamic 4-CV images of 60 fetuses exposed to maternal diabetes (MD) and 60 controls were retrospectively collected between 19 and 37 weeks of gestation. Speckle-tracking analysis was used to compute and compare GSI, GLS and FAC of the right ventricle (RV) and the left ventricle (LV) between the groups. By definition, GSI was the ratio of the epicardial basal-apical length in end-diastole (BAL) to the overall transverse length of RV and LV in end-diastole (TL). The FAC was calculated by dividing the difference between end-diastolic area and end-systolic area by the end-diastolic area. Similarly, the GLS of the RV and LV was obtained by dividing the difference between the endocardial length in end-systole and endocardial length in end-diastole to the endocardial length in end-diastole. Data for conventional echocardiographic parameters, standard biological measurements of fetus and maternal baseline characteristics were also recorded and compared between the groups. Linear regression analysis was performed to assess the association between age, BMI and the inter-ventricular septum thickness (IVST).

RESULTS

Gestational age at the time of examination did not differ significantly between the control and gestational diabetes group (p = 0.74). In fetuses exposed to MD, the thickness of the IVS was higher while the FAC of RV, GLS of RV and the GSI were all significantly lower. The FAC and global strain of LV generally decreased with progress in gestation but the difference between the two groups was not statistically significant. Conventional echocardiography in fetuses exposed to MD revealed a lower mitral E/A ratio and a larger myocardial performance index (MPI) of the RV and LV. Although the annular plane systolic excursion (MAPSE), tricuspid annular plane systolic excursion (TAPSE) and septal annular plane systolic excursion (SAPSE) were also lower in this group, the difference was not statistically significant compared to fetuses of the control group. No regression relationship between age, BMI and IVST were noticed in any group.

CONCLUSION

This study found that diastolic dysfunction among fetuses of gestational diabetic mothers is accompanied by global cardiac deformation and functional decrease of the RV in systole in the second and third trimester. The GSI, global strain and FAC acquired by SRI can be used as convenient and reliable quantitative parameters in the assessment of cardiac function in fetuses exposed to gestational diabetes.

Late-Pregnancy Fetal Hypoxia Is Associated With Altered Glucose Metabolism and Adiposity in Young Adult Offspring of Women With Type 1 Diabetes

OBJECTIVE

To investigate associations between exposure to fetal hypoxia and indicators of metabolic health in young adult offspring of women with type 1 diabetes (OT1D).

METHODS

156 OT1D born between 7/1995 and 12/2000 at Helsinki University Hospital, Finland, were invited for follow-up between 3/2019 and 11/2019. A control group of 442 adults born from non-diabetic pregnancies, matched for date and place of birth, was obtained from the Finnish Medical Birth Register. In total, 58 OT1D and 86 controls agreed to participate. All OT1D had amniotic fluid (AF) sampled for erythropoietin (EPO) measurement within two days before delivery in order to diagnose fetal hypoxia. In total, 29 OTID had an AF EPO concentration <14.0 mU/l, defined as normal, and were categorized into the low EPO (L-EPO) group. The remaining 29 OT1D had AF EPO ≥14.0 mU/ml, defined as fetal hypoxia, and were categorized into the high EPO (H-EPO) group. At the age of 18-23 years, participants underwent a 2-h 75g oral glucose tolerance test (OGTT) in addition to height, weight, waist circumference, body composition, blood pressure, HbA_1c, cholesterol, triglyceride, high-sensitivity CRP and leisure-time physical activity measurements.

RESULTS

Two OT1D were diagnosed with diabetes and excluded from further analyses. At young adult age, OT1D in the H-EPO group had a higher BMI than those in the L-EPO group. In addition, among female participants, waist circumference and body fat percentage were highest in the H-EPO group. In the OGTTs, the mean (SD) 2-h post-load plasma glucose (mmol/L) was higher in the H-EPO [6.50 (2.11)] than in the L-EPO [5.21 (1.10)] or control [5.67 (1.48)] offspring (p=0.009). AF EPO concentrations correlated positively with 2-h post-load plasma glucose [r=0.35 (95% CI: 0.07 to 0.62)] and serum insulin [r=0.44 (95% CI: 0.14 to 0.69)] concentrations, even after adjusting for maternal BMI, birth weight z-score, gestational age at birth and adult BMI. Control, L-EPO and H-EPO groups did not differ with regards to other assessed parameters.

CONCLUSIONS

High AF EPO concentrations in late pregnancy, indicating fetal hypoxia, are associated with increased adiposity and elevated post-load glucose and insulin concentrations in young adult OT1D.

Effects of chronic hyperinsulinemia on metabolic pathways and insulin signaling in the fetal liver

The effect of chronic of hyperinsulinemia in the fetal liver is poorly understood. Here, we produced hyperinsulinemia with euglycemia for ∼8 days in fetal sheep [hyperinsulinemic (INS)] at 0.9 gestation. INS fetuses had increased insulin and decreased oxygen and amino acid (AA) concentrations compared with saline-infused fetuses [control (CON)]. Glucose (whole body) utilization rates were increased, as expected, in INS fetuses. In the liver, however, there were few differences in genes and metabolites related to glucose and lipid metabolism and no activation of insulin signaling proteins (Akt and mTOR). There was increased p-AMPK activation and decreased mitochondrial mass (PGC1A expression, mitochondrial DNA content) in INS livers. Using an unbiased multivariate analysis with 162 metabolites, we identified effects on AA and one-carbon metabolism in the INS liver. Expression of the transaminase BCAT2 and glutaminase genes GLS1 and GLS2 was decreased, supporting decreased AA utilization. We further evaluated the roles of hyperinsulinemia and hypoxemia, both present in INS fetuses, on outcomes in the liver. Expression of PGC1A correlated only with hyperinsulinemia, p-AMPK correlated only with hypoxemia, and other genes and metabolites correlated with both hyperinsulinemia and hypoxemia. In fetal hepatocytes, acute treatment with insulin activated p-Akt and decreased PGC1A, whereas hypoxia activated p-AMPK. Overall, chronic hyperinsulinemia produced greater effects on amino acid metabolism compared with glucose and lipid metabolism and a novel effect on one-carbon metabolism in the fetal liver. These hepatic metabolic responses may result from the downregulation of insulin signaling and antagonistic effects of hypoxemia-induced AMPK activation that develop with chronic hyperinsulinemia.

Is obesity in pregnancy associated with signs of chronic fetal hypoxia?

INTRODUCTION

The prevalence of obesity in pregnancy is increasing worldwide. Maternal obesity increases risks of severe fetal and neonatal complications. The underlying pathophysiological mechanisms are unclear. One possible contributing factor could be chronic fetal hypoxia. The aim of this study was to compare placentas from women with and without obesity with respect to placental lesions, which could reflect compensatory mechanisms in response to chronic fetal hypoxia as well as lesions possibly leading to chronic fetal hypoxia. In addition, levels of erythropoietin in cord blood were compared between offspring of lean and obese women.

MATERIAL AND METHODS

This cohort study included 180 women with uneventful, full-term, singleton pregnancies, out of which 91 lean women had a body mass index (BMI) of 18.5-24.9 kg/m² and 89 women had obesity (BMI ≥30 kg/m² ). Women were recruited at Södersjukhuset between 16 October 2018 and 2 December 2019. Placentas were investigated by two senior perinatal pathologists, who were blinded for maternal BMI. Cord blood was analyzed for levels of erythropoietin.

RESULTS

Levels of erythropoietin in cord blood increased with maternal BMI (P = .01, β = 0.97, 95% CI 0.27-1.68). There was no difference between placentas of obese and lean women in number of placental lesions reflecting chronic fetal hypoxia or in lesions that could possibly lead to chronic fetal hypoxia.

CONCLUSIONS

This study of term and uneventful pregnancies demonstrated a positive association between maternal obesity and concentrations of erythropoietin in cord blood at birth. This finding supports the hypothesis of chronic fetal hypoxia as a risk factor for complications in the pregnancies of obese women. There were no differences in lesions associated with hypoxia between placentas of obese and lean women.

Pregnancy-induced hypertension is an independent risk factor for meconium aspiration syndrome: A retrospective population based cohort study

OBJECTIVE

Meconium aspiration syndrome (MAS), possibly resulting from fetal hypoxia, is a respiratory distress disorder in the infant. Pregnancy-induced hypertension (PIH) can cause placental dysfunction and lead to fetal hypoxia, which may induce the development of MAS. Therefore, the aim of this study was to determine the association between PIH and MAS and to identify the predictive risk factors.

MATERIALS AND METHODS

This was a retrospective cohort study. We selected patients with newly diagnosed PIH and a matched cohort group from the Taiwan National Health Insurance Research Database (NHIRD), from January 1, 2000 till December 31, 2013. For each patient in the PIH cohort, 4 subjects without PIH, matched for age and year of delivery, were randomly selected as the comparison cohort. The incidence of meconium aspiration syndrome was assessed in both groups.

RESULTS

Among the 23.3 million individuals registered in the NHIRD, 29,013 patients with PIH and 116,052 matched controls were identified. Patients who experienced PIH had a higher incidence of MAS than did those without PIH. According to a multivariate analysis, PIH (odds ratio [OR] = 1.70, 95% confidence interval [CI] = 1.49-1.93, p < 0.0001) was independently associated with increased risk of MAS. Additionally, age ≥30 years (OR = 1.26, 95% CI = 1.12-1.42, p = 0.0001), nulliparity (OR = 1.13, 95% CI = 1.01-1.27, p = 0.0367) and patients with diabetes mellitus (OR = 3.09, 95% CI = 1.35-7.09, p = 0.0078) were also independent risk factors of MAS.

CONCLUSION

Patients with PIH obtained higher subsequent risk for the development of MAS than those without PIH. Besides, age ≥30 years, nulliparity and patients with diabetes mellitus are the independent risk factors of developing MAS.

Fetal chronic hypoxia and oxidative stress in diabetic pregnancy. Could fetal erythropoietin improve offspring outcomes?

Oxidative stress is responsible for microvascular complications (hypertension, nephropathy, retinopathy, peripheral neuropathy) of diabetes, which during pregnancy increase both maternal and fetal complications. Chronic hypoxia and hyperglycemia result in increased oxidative stress and decreased antioxidant enzyme activity. However, oxidative stress induces also anti-oxidative reactions both in pregnant diabetes patients and in their fetuses. Not all type 1 diabetes patients with long-lasting disease develop microvascular complications, which suggests that some of these patients have protective mechanisms against these complications. Fetal erythropoietin (EPO) is the main regulator of red cell production in the mother and in the fetus, but it has also protective effects in various maternal and fetal tissues. This dual effect of EPO is based on EPO receptor (EPO-R) isoforms, which differ structurally and functionally from the hematopoietic EPO-R isoform. The tissue protective effects of EPO are based on its anti-apoptotic, anti-oxidative, anti-inflammatory, cell proliferative and angiogenic properties. Recent experimental and clinical studies have shown that EPO has also positive metabolic effects on hyperglycemia and diabetes, although these have not yet been fully delineated. Whether the tissue protective and metabolic effects of EPO could have clinical benefits, are important topics for future research in diabetic pregnancies.

Risk factors and outcomes for neonatal hypoglycaemia and neonatal hyperbilirubinaemia in pregnancies complicated by gestational diabetes mellitus: a single centre retrospective 3-year review

AIM

To determine risk factors associated with neonatal hypoglycaemia and hyperbilirubinaemia, and assess their impact on neonatal outcomes in pregnancies complicated by gestational diabetes mellitus (GDM).

METHODS

Retrospective review investigating all pregnancies complicated by GDM at Campbelltown Hospital (Sydney, Australia) between 1 January 2013 and 31 December 2015. Main outcomes measured were neonatal hypoglycaemia (capillary glucose levels < 1.8 mmol/l) and hyperbilirubinaemia (total serum bilirubin levels greater than age-appropriate thresholds for phototherapy). Adjusted odds ratios [95% confidence interval (CI)] are shown, calculated by multivariable logistic regression.

RESULTS

Some 60 (7.8%) infants developed hypoglycaemia, 58 (7.5%) developed hyperbilirubinaemia and 13 (1.7%) developed both. Risk of developing hypoglycaemia increased 1.8-fold (95% CI 1.3-2.6, P < 0.001) per gestational week at GDM diagnosis, 1.1-fold (95% CI 1.0-1.3, P = 0.04) per mmol/l maternal fasting glucose, 6.2-fold (95% CI 2.6-16.2, P < 0.001) with maternal history of macrosomia, 10.8-fold (95% CI 4.1-27.6, P < 0.001) with multiple pregnancy and 1.1-fold (95% CI 1.0-1.3, P = 0.04) per gestational week at birth. Risk of hyperbilirubinaemia increased with multiple pregnancy (26.4; 95% CI 11.7-59.7, P < 0.001), and 1.5-fold (95% CI 1.1-2.1, P = 0.01) per gestational week at GDM diagnosis. Hypoglycaemia was associated with a 2.8-fold (95% CI 1.1-7.1, P = 0.03) increased risk of macrosomia, a 5.4-fold (95% CI 1.1-27.3, P = 0.04) excess risk of shoulder dystocia and a 6.4-fold increased risk of 5-min APGAR ≤ 7 (95% CI 1.2-1.7, P < 0.001). Hyperbilirubinaemia was associated with an excess risk of polycythaemia (packed cell volume > 0.6; 97.1, 95% CI 38.9-241.5, P < 0.001).

CONCLUSIONS

Neonatal hypoglycaemia and hyperbilirubinaemia largely occur in different pregnancies. Both are associated with earlier GDM diagnosis; however, hypoglycaemia is more associated with maternal glycaemia and its sequelae, and hyperbilirubinaemia is associated with polycythaemia.

Neonatal Near Miss among Newborns of Women with Type 1 Diabetes Mellitus

Objective

To investigate the frequency of neonatal near miss (NNM) and associate it with maternal morbidity in newborns of women with type 1 diabetes mellitus (T1DM).

Methods

This was a cross-sectional retrospective study from a secondary analysis of data retrieved from medical records of pregnant women with T1DM cared at a Brazilian university hospital between 2005 and 2015. Maternal near miss (MNM) and potentially life-threatening conditions (PTLC) were classified according to the World Health Organization criteria. NNM was classified according to the Pan American Health Organization Neonatal Near Miss Working Group criteria. Association of maternal morbidity with NNM was assessed using chi-square test.

Results

There were 122 newborns (NB) among 137 T1DM pregnancies. Thirty-seven NB presented NNM-incidence of 303 NNM per 1000 live births (37/122). NNM was associated with MNM (P < 0.001, OR (95% CI): 17.15 (1.85-159.12)). PLTC did not increase the odds of NNM (P=0.07; OR (95% CI): 2.1281 (0.92-4.91)). Seven newborns died, six of them from pregnancies without severe maternal morbidity. 71% of the neonatal death (5/7) occurred in malformed neonates.

Conclusion

MNM was associated with NNM among women with T1DM, and PLTC, paradoxically, did not increase NNM.

Mechanisms of death in structurally normal stillbirths

Objectives To investigate mechanisms of in utero death in normally formed fetuses by measuring amniotic fluid (AF) biomarkers for hypoxia (erythropoietin [EPO]), myocardial damage (cardiac troponin I [cTnI]) and brain injury (glial fibrillary acidic protein [GFAP]), correlated with risk factors for fetal death and placental histopathology. Methods This retrospective, observational cohort study included intrauterine deaths with transabdominal amniocentesis prior to induction of labor. Women with a normal pregnancy and an indicated amniocentesis at term were randomly selected as controls. AF was assayed for EPO, cTnI and GFAP using commercial immunoassays. Placental histopathology was reviewed, and CD15-immunohistochemistry was used. Analyte concentrations >90th centile for controls were considered "raised". Raised AF EPO, AF cTnI and AF GFAP concentrations were considered evidence of hypoxia, myocardial and brain injury, respectively. Results There were 60 cases and 60 controls. Hypoxia was present in 88% (53/60), myocardial damage in 70% (42/60) and brain injury in 45% (27/60) of fetal deaths. Hypoxic fetuses had evidence of myocardial injury, brain injury or both in 77% (41/53), 49% (26/53) and 13% (7/53) of cases, respectively. Histopathological evidence for placental dysfunction was found in 74% (43/58) of these cases. Conclusion Hypoxia, secondary to placental dysfunction, was found to be the mechanism of death in the majority of fetal deaths among structurally normal fetuses. Ninety-one percent of hypoxic fetal deaths sustained brain, myocardial or both brain and myocardial injuries in utero. Hypoxic myocardial injury was an attributable mechanism of death in 70% of the cases. Non-hypoxic cases may be caused by cardiac arrhythmia secondary to a cardiac conduction defect.

Hypoxia: From Placental Development to Fetal Programming

Hypoxia may influence normal and different pathological processes. Low oxygenation activates a variety of responses, many of them regulated by hypoxia-inducible factor 1 complex, which is mostly involved in cellular control of O₂ consumption and delivery, inhibition of growth and development, and promotion of anaerobic metabolism. Hypoxia plays a significant physiological role in fetal development; it is involved in different embryonic processes, for example, placentation, angiogenesis, and hematopoiesis. More recently, fetal hypoxia has been associated directly or indirectly with fetal programming of heart, brain, and kidney function and metabolism in adulthood. In this review, the role of hypoxia in fetal development, placentation, and fetal programming is summarized. Hypoxia is a basic mechanism involved in different pregnancy disorders and fetal health developmental complications. Although there are scientific data showing that hypoxia mediates changes in the growth trajectory of the fetus, modulates gene expression by epigenetic mechanisms, and determines the health status later in adulthood, more mechanistic studies are needed. Furthermore, if we consider that intrauterine hypoxia is not a rare event, and can be a consequence of unavoidable exposures to air pollution, nutritional deficiencies, obesity, and other very common conditions (drug addiction and stress), the health of future generations may be damaged and the incidence of some diseases will markedly increase as a consequence of disturbed fetal programming. Birth Defects Research 109:1377-1385, 2017.© 2017 Wiley Periodicals, Inc.

Fetal Cardiac Function in Maternal Diabetes: A Conventional and Speckle-Tracking Echocardiographic Study

BACKGROUND

Intrauterine exposure to a diabetic environment is associated with adverse fetal myocardial remodeling. The aim of this study was to assess the biventricular systolic and diastolic function of fetuses exposed to maternal diabetes (MD) compared with control subjects, using a comprehensive cardiac functional assessment and exploring the role of speckle-tracking to assess myocardial deformation. The authors hypothesized that fetuses exposed to MD present signs of biventricular dysfunction, which can be detected by deformation analysis.

METHODS

A cross-sectional study was conducted in 129 fetuses with structurally normal hearts, including 76 fetuses of mothers with diabetes and 53 of mothers without diabetes. Maternal baseline characteristics, standard fetoplacental Doppler indices, and conventional echocardiographic and myocardial deformation parameters were prospectively collected at 30 to 33 weeks of gestation.

RESULTS

Fetuses of mothers with diabetes had a significantly thicker interventricular septum compared with control subjects (median, 4.25 mm [interquartile range (IQR), 3.87-4.50 mm] vs 3.67 mm [IQR, 3.40-3.93 mm), P < .001), but no effect modification was demonstrated on myocardial deformation analysis. No significant differences were found in conventional systolic and diastolic functional parameters for the left ventricle and right ventricle, except for lower left ventricular cardiac output in the MD group (median, 320 mL/min [IQR, 269-377 mL/min] vs 365 mL/min [IQR, 311-422 mL/min], P < .05]. Deformation analysis demonstrated a significantly lower early diastolic strain rate (SRe) and late diastolic strain rate (SRa) for both ventricles in the MD group (left ventricle: SRe 1.85 ± 0.72 vs 2.26 ± 0.68 sec^-1, SRa 1.50 ± 0.52 vs 1.78 ± 0.57 sec^-1; right ventricle: SRe 1.57 ± 0.73 vs 1.97 ± 0.73 sec^-1, SRa 2 ± 0.77 vs 1.68 ± 0.79 sec^-1; P < .05), suggesting biventricular diastolic impairment. Additionally, the right ventricle presented a lower global longitudinal strain in the study group (-13.67 ± 4.18% vs -15.52 ± 3.86%, P < .05). Multivariate analysis revealed that maternal age is an independent predictor of left and right ventricular global longitudinal strain (P < .05), with a significant effect only in MD after group stratification.

CONCLUSIONS

Fetuses of mothers with diabetes present signs of biventricular diastolic dysfunction and right ventricular systolic dysfunction by deformation analysis in the third trimester of pregnancy. They may represent a special indication group for functional cardiac assessment, independently of septal hypertrophy. Two-dimensional speckle-tracking could offer an additional benefit over conventional echocardiography to detect subclinical unfavorable changes in myocardial function in this population.

Ontogeny of Sex-Related Differences in Foetal Developmental Features, Lipid Availability and Fatty Acid Composition

Sex-related differences in lipid availability and fatty acid composition during swine foetal development were investigated. Plasma cholesterol and triglyceride concentrations in the mother were strongly related to the adequacy or inadequacy of foetal development and concomitant activation of protective growth in some organs (brain, heart, liver and spleen). Cholesterol and triglyceride availability was similar in male and female offspring, but female foetuses showed evidence of higher placental transfer of essential fatty acids and synthesis of non-essential fatty acids in muscle and liver. These sex-related differences affected primarily the neutral lipid fraction (triglycerides), which may lead to sex-related postnatal differences in energy partitioning. These results illustrate the strong influence of the maternal lipid profile on foetal development and homeorhesis, and they confirm and extend previous reports that female offspring show better adaptive responses to maternal malnutrition than male offspring. These findings may help guide dietary interventions to ensure adequate fatty acid availability for postnatal development.

Fetal adaptations in insulin secretion result from high catecholamines during placental insufficiency

Placental insufficiency and intrauterine growth restriction (IUGR) of the fetus affects approximately 8% of all pregnancies and is associated with short- and long-term disturbances in metabolism. In pregnant sheep, experimental models with a small, defective placenta that restricts delivery of nutrients and oxygen to the fetus result in IUGR. Low blood oxygen concentrations increase fetal plasma catecholamine concentrations, which lower fetal insulin concentrations. All of these observations in sheep models with placental insufficiency are consistent with cases of human IUGR. We propose that sustained high catecholamine concentrations observed in the IUGR fetus produce developmental adaptations in pancreatic β-cells that impair fetal insulin secretion. Experimental evidence supporting this hypothesis shows that chronic elevation in circulating catecholamines in IUGR fetuses persistently inhibits insulin concentrations and secretion. Elevated catecholamines also allow for maintenance of a normal fetal basal metabolic rate despite low fetal insulin and glucose concentrations while suppressing fetal growth. Importantly, a compensatory augmentation in insulin secretion occurs following inhibition or cessation of catecholamine signalling in IUGR fetuses. This finding has been replicated in normally grown sheep fetuses following a 7-day noradrenaline (norepinephrine) infusion. Together, these programmed effects will potentially create an imbalance between insulin secretion and insulin-stimulated glucose utilization in the neonate which probably explains the transient hyperinsulinism and hypoglycaemia in some IUGR infants.

Oxygen and oxidative stress in the perinatal period

Fetal life evolves in a hypoxic environment. Changes in the oxygen content in utero caused by conditions such as pre-eclampsia or type I diabetes or by oxygen supplementation to the mother lead to increased free radical production and correlate with perinatal outcomes. In the fetal-to-neonatal transition asphyxia is characterized by intermittent periods of hypoxia ischemia that may evolve to hypoxic ischemic encephalopathy associated with neurocognitive, motor, and neurosensorial impairment. Free radicals generated upon reoxygenation may notably increase brain damage. Hence, clinical trials have shown that the use of 100% oxygen given with positive pressure in the airways of the newborn infant during resuscitation causes more oxidative stress than using air, and increases mortality. Preterm infants are endowed with an immature lung and antioxidant system. Clinical stabilization of preterm infants after birth frequently requires positive pressure ventilation with a gas admixture that contains oxygen to achieve a normal heart rate and arterial oxygen saturation. In randomized controlled trials the use high oxygen concentrations (90% to 100%) has caused more oxidative stress and clinical complications that the use of lower oxygen concentrations (30-60%). A correlation between the amount of oxygen received during resuscitation and the level of biomarkers of oxidative stress and clinical outcomes was established. Thus, based on clinical outcomes and analytical results of oxidative stress biomarkers relevant changes were introduced in the resuscitation policies. However, it should be underscored that analysis of oxidative stress biomarkers in biofluids has only been used in experimental and clinical research but not in clinical routine. The complexity of the technical procedures, lack of automation, and cost of these determinations have hindered the routine use of biomarkers in the clinical setting. Overcoming these technical and economical difficulties constitutes a challenge for the immediate future since accurate evaluation of oxidative stress would contribute to improve the quality of care of our neonatal patients.

Chronic anemic hypoxemia attenuates glucose-stimulated insulin secretion in fetal sheep

Fetal insulin secretion is inhibited by acute hypoxemia. The relationship between prolonged hypoxemia and insulin secretion, however, is less well defined. To test the hypothesis that prolonged fetal hypoxemia impairs insulin secretion, studies were performed in sheep fetuses that were bled to anemic conditions for 9 ± 0 days (anemic, n = 19) and compared with control fetuses (n = 15). Arterial hematocrit and oxygen content were 34% and 52% lower, respectively, in anemic vs. control fetuses (P < 0.0001). Plasma glucose concentrations were 21% higher in the anemic group (P < 0.05). Plasma norepinephrine and cortisol concentrations increased 70% in the anemic group (P < 0.05). Glucose-, arginine-, and leucine-stimulated insulin secretion all were lower (P < 0.05) in anemic fetuses. No differences in pancreatic islet size or β-cell mass were found. In vitro, isolated islets from anemic fetuses secreted insulin in response to glucose and leucine as well as control fetal islets. These findings indicate a functional islet defect in anemic fetuses, which likely involves direct effects of low oxygen and/or increased norepinephrine on insulin release. In pregnancies complicated by chronic fetal hypoxemia, increasing fetal oxygen concentrations may improve insulin secretion.

Fetal growth-retardation and brain-sparing by malnutrition are associated to changes in neurotransmitters profile

The present study assesses possible changes in the levels of different neurotransmitters (catecholamines and indoleamines) in fetuses affected by nutrient shortage. Hence, we determined the concentration of catecholamines and indoleamines at the hypothalamus of 56 swine fetuses obtained at both 70 and 90days of pregnancy (n=33 and 23 fetuses, respectively). The degree of fetal development and the fetal sex affected the neurotransmitters profile at both stages. At Day 70, there were found higher mean concentrations of l-DOPA in both female and male fetuses with severe IUGR; male fetuses with severe IUGR also showed higher concentrations of TRP than normal male littermates. At Day 90 of pregnancy, the differences between sexes were more evident. There were no significant effects from either severe IUGR on the neurotransmitter profile in male fetuses. However, in the females, a lower body-weight was related to lower concentrations of l-DOPA and TRP and those female fetuses affected by severe IUGR evidenced lower HVA concentration. In conclusion, the fetal synthesis and use of neurotransmitters increase with time of pregnancy but, in case of IUGR, both catecholamines and indoleamines pathways are affected by sex-related effects.

Chronic Hyperinsulinemia Increases Myoblast Proliferation in Fetal Sheep Skeletal Muscle

Insulin is an important fetal growth factor. However, chronic experimental hyperinsulinemia in the fetus fails to accelerate linear and lean mass growth beyond normal rates. Mechanisms preventing accelerated lean mass accretion during hyperinsulinemia are unknown. To address potential mechanisms, late-gestation fetal sheep were infused with iv insulin and glucose to produce euglycemic hyperinsulinemia (INS) or saline for 7-9 days. Fetal substrate uptake and protein metabolic rates were measured. INS fetuses had 1.5-fold higher insulin concentrations (P < .0001) and equivalent glucose concentrations. INS fetuses had 20% more Pax7(+) nuclei in the biceps femoris, which indicates the potential for hyperinsulinemia to increase the number of myoblasts within late-gestation fetal skeletal muscle. Additionally, the percentage of Pax7(+) myoblasts that expressed Ki-67 was 1.3-fold higher and expression of myogenic regulatory factors was 50% lower in INS fetuses (MYF5 and MYOG [myogenin], P < .005), which indicates a shift toward myoblast proliferation over differentiation. There were no differences for fetal body, organ, or muscle weights, although INS placentas weighed 28% less (P < .05). Protein synthesis and accretion rates did not change in INS fetuses, nor did fiber muscle size. Essential amino acid concentrations were lower in the INS group (P < .05) except for tryptophan. Umbilical blood flow, net total amino acids, and O2 uptakes rates did not differ between groups. Arterial O2 content was 33% lower (P < .005) and norepinephrine was 100% higher in the INS fetuses (P < .01), all of which are factors that may counteract fetal protein accretion during hyperinsulinemia despite an increase in myoblast proliferation.

Chronic anemic hypoxemia increases plasma glucagon and hepatic PCK1 mRNA in late-gestation fetal sheep

Hepatic glucose production (HGP) normally begins just prior to birth. Prolonged fetal hypoglycemia, intrauterine growth restriction, and acute hypoxemia produce an early activation of fetal HGP. To test the hypothesis that prolonged hypoxemia increases factors which regulate HGP, studies were performed in fetuses that were bled to anemic conditions (anemic: n = 11) for 8.9 ± 0.4 days and compared with control fetuses (n = 7). Fetal arterial hematocrit and oxygen content were 32% and 50% lower, respectively, in anemic vs. controls (P < 0.005). Arterial plasma glucose was 15% higher in the anemic group (P < 0.05). Hepatic mRNA expression of phosphonenolpyruvate carboxykinase (PCK1) was twofold higher in the anemic group (P < 0.05). Arterial plasma glucagon concentrations were 70% higher in anemic fetuses compared with controls (P < 0.05), and they were positively associated with hepatic PCK1 mRNA expression (P < 0.05). Arterial plasma cortisol concentrations increased 90% in the anemic fetuses (P < 0.05), but fetal cortisol concentrations were not correlated with hepatic PCK1 mRNA expression. Hepatic glycogen content was 30% lower in anemic vs. control fetuses (P < 0.05) and was inversely correlated with fetal arterial plasma glucagon concentrations. In isolated primary fetal sheep hepatocytes, incubation in low oxygen (3%) increased PCK1 mRNA threefold compared with incubation in normal oxygen (21%). Together, these results demonstrate that glucagon and PCK1 may potentiate fetal HGP during chronic fetal anemic hypoxemia.

Potential benefits of physical activity during pregnancy for the reduction of gestational diabetes prevalence and oxidative stress

Changes in quality of nutrition, habits, and physical activity in modern societies increase susceptibility to obesity, which can deleteriously affect pregnancy outcome. In particular, a sedentary lifestyle causes dysfunction in blood flow, which impacts the cardiovascular function of pregnant women. The main molecular mechanism responsible for this effect is the synthesis and bioavailability of nitric oxide, a phenomenon regulated by the antioxidant capacity of endothelial cells. These alterations affect the vascular health of the mother and vascular performance of the placenta, the key organ responsible for the healthy development of the fetus. In addition to the increases in systemic vascular resistance in the mother, placental oxidative stress also affects the feto-placental blood flow. These changes can be integrated into the proteomics and metabolomics of newborns.

Cumulative biomedical risk and social cognition in the second year of life: prediction and moderation by responsive parenting

At 18 months, children show marked variability in their social-cognitive skill development, and the preponderance of past research has focused on constitutional and contextual factors in explaining this variability. Extending this literature, the current study examined whether cumulative biomedical risk represents another source of variability in social cognition at 18 months. Further, we aimed to determine whether responsive parenting moderated the association between biomedical risk and social cognition. A prospective community birth cohort of 501 families was recruited at the time of the child's birth. Cumulative biomedical risk was measured as a count of 10 prenatal/birth complications. Families were followed up at 18 months, at which point social-cognitive data was collected on children's joint attention, empathy, cooperation, and self-recognition using previously validated tasks. Concurrently, responsive maternal behavior was assessed through observational coding of mother-child interactions. After controlling for covariates (e.g., age, gender, child language, socioeconomic variables), both cumulative biomedical risk and maternal responsivity significantly predicted social cognition at 18 months. Above and beyond these main effects, there was also a significant interaction between biomedical risk and maternal responsivity, such that higher biomedical risk was significantly associated with compromised social cognition at 18 months, but only in children who experienced low levels of responsive parenting. For those receiving comparatively high levels of responsive parenting, there was no apparent effect of biomedical risk on social cognition. This study shows that cumulative biomedical risk may be one source of inter-individual variability in social cognition at 18 months. However, positive postnatal experiences, particularly high levels of responsive parenting, may protect children against the deleterious effects of these risks on social cognition.

Evaluating the fetus at risk for cardiopulmonary compromise

The in-utero environment is relatively hypoxic, but fetal physiologic adaptation assures adequate tissue oxygen supply. Fetal reactions to acute or chronic hypoxia are different and are modified by the preceding fetal condition. Acute fetal hypoxia episodes are often not preventable. By contrast, good obstetric care during labor may prevent poor fetal outcome in many cases of acute fetal hypoxia. The pathophysiology of chronic fetal hypoxia caused by placental insufficiency differs from chronic fetal hypoxia seen during the last weeks of diabetic pregnancies. The efficacy of antenatal fetal surveillance methods in preventing perinatal complications is different in these two conditions. Electronic fetal heart rate testing and Doppler flow assessment methods have been successful in detecting chronic fetal hypoxia caused by placental insufficiency. However, these methods have been unable to prevent chronic fetal hypoxia complications in diabetic pregnancies. Therefore, research to find new strategies and early and reliable biomarkers is necessary to assess fetal well-being and to decide when to deliver the fetus.

Maternal hyperglycemia leads to fetal cardiac hyperplasia and dysfunction in a rat model

Accelerated fetal myocardial growth with altered cardiac function is a well-documented complication of human diabetic pregnancy, but its pathophysiology is still largely unknown. Our aim was to explore the mechanisms of fetal cardiac remodeling and cardiovascular hemodynamics in a rat model of maternal pregestational streptozotocin-induced hyperglycemia. The hyperglycemic group comprised 107 fetuses (10 dams) and the control group 219 fetuses (20 dams). Fetal cardiac function was assessed serially by Doppler ultrasonography. Fetal cardiac to thoracic area ratio, newborn heart weight, myocardial cell proliferative and apoptotic activities, and cardiac gene expression patterns were determined. Maternal hyperglycemia was associated with increased cardiac size, proliferative, apoptotic and mitotic activities, upregulation of genes encoding A- and B-type natriuretic peptides, myosin heavy chain types 2 and 3, uncoupling proteins 2 and 3, and the angiogenetic tumor necrosis factor receptor superfamily member 12A. The genes encoding Kv channel-interacting protein 2, a regulator of electrical cardiac phenotype, and the insulin-regulated glucose transporter 4 were downregulated. The heart rate was lower in fetuses of hyperglycemic dams. At 13-14 gestational days, 98% of fetuses of hyperglycemic dams had holosystolic atrioventricular valve regurgitation and decreased outflow mean velocity, indicating diminished cardiac output. Maternal hyperglycemia may lead to accelerated fetal myocardial growth by cardiomyocyte hyperplasia. In fetuses of hyperglycemic dams, expression of key genes that control and regulate cardiomyocyte electrophysiological properties, contractility, and metabolism are altered and may lead to major functional and clinical implications on the fetal heart.

Intermittent maternal hypoxia has an influence on regional expression of endothelial nitric oxide synthase in fetal arteries of rabbits

BACKGROUND

Maternal hypoxia induces sustained fetal adaptations associated with changes in gene expression. We hypothesized that intermittent maternal hypoxia has an influence on regional expression of endothelial nitric oxide synthase (eNOS) in fetal arteries of New Zealand White rabbits.

METHODS

Timed-pregnant New Zealand White rabbits (term = 30 ± 1 d) were randomly assigned to a normoxic control group (n = 5) or a hypoxia group (12% O2, n = 5) during days 10-29 of pregnancy. At the end of pregnancy (29 d gestation), blood samples were collected from mothers and fetuses. Carotid and femoral arteries of fetuses were extracted for eNOS mRNA and protein concentration and analysis of total NOS activities.

RESULTS

Our data demonstrate that chronic intermittent maternal hypoxia significantly increased eNOS mRNA and protein concentrations and total NOS activities in carotid artery segments but decreased eNOS mRNA and protein concentrations and total NOS activities in femoral artery segments in the same fetuses. Vascular endothelial cells, but not smooth muscle cells, of fetal rabbits exhibited positive immunostaining for the eNOS protein.

CONCLUSION

These observations suggest that chronic hypoxia can regulate regional expression of eNOS as an adaptive response to hypoxic stress in fetal arteries.

Association of maternal diabetes and child asthma

BACKGROUND

Perinatal programming is an emerging theory for the fetal origins of chronic disease. Maternal asthma and environmental tobacco smoke (ETS) are two of the best-known triggers for the perinatal programming of asthma, while the potential role of maternal diabetes has not been widely studied.

OBJECTIVE

To determine if maternal diabetes is associated with child asthma, and if so, whether it modifies the effects of ETS exposure and maternal asthma.

METHODS

We studied 3,574 Canadian children, aged 7-8 years, enrolled in a population-based birth cohort. Standardized questionnaires were completed by the children's parents, and data were analyzed by multivariable logistic regression.

RESULTS

Asthma was reported in 442 children (12.4%). Compared to those without asthma, asthmatic children were more likely to have mothers (P = 0.003), but not fathers (P = 0.89), with diabetes. Among children without maternal history of diabetes, the likelihood of child asthma was 1.4-fold higher in those exposed to ETS (adjusted odds ratio, 1.40; 95% confidence interval, 1.13-1.73), and 3.6-fold higher in those with maternal asthma (3.59; 2.71-4.76). Among children born to diabetic mothers, these risks were amplified to 5.7-fold (5.68; 1.18-27.37) and 11.3-fold (11.30; 2.26-56.38), respectively. In the absence of maternal asthma or ETS, maternal diabetes was not associated with child asthma (0.65, 0.16-2.56).

CONCLUSION

Our findings suggest that maternal diabetes may contribute to the perinatal programming of child asthma by amplifying the detrimental effects of ETS exposure and maternal asthma.

Contribution of increased VEGF receptors to hypoxic changes in fetal ovine carotid artery contractile proteins

Recent studies suggest that vascular endothelial growth factor (VEGF) can modulate smooth muscle phenotype and, consequently, the composition and function of arteries upstream from the microcirculation, where angiogenesis occurs. Given that hypoxia potently induces VEGF, the present study explores the hypothesis that, in fetal arteries, VEGF contributes to hypoxic vascular remodeling through changes in abundance, organization, and function of contractile proteins. Pregnant ewes were acclimatized at sea level or at altitude (3,820 m) for the final 110 days of gestation. Endothelium-denuded carotid arteries from full-term fetuses were used fresh or after 24 h of organ culture in a physiological concentration (3 ng/ml) of VEGF. After 110 days, hypoxia had no effect on VEGF abundance but markedly increased abundance of the Flk-1 (171%) and Flt-1 (786%) VEGF receptors. Hypoxia had no effect on smooth muscle α-actin (SMαA), decreased myosin light chain (MLC) kinase (MLCK), and increased 20-kDa regulatory MLC (MLC(20)) abundances. Hypoxia also increased MLCK-SMαA, MLC(20)-SMαA, and MLCK-MLC(20) colocalization. Compared with hypoxia, organ culture with VEGF produced the same pattern of changes in contractile protein abundance and colocalization. Effects of VEGF on colocalization were blocked by the VEGF receptor antagonists vatalanib (240 nM) and dasatinib (6.3 nM). Thus, through increases in VEGF receptor density, hypoxia can recruit VEGF to help mediate remodeling of fetal arteries upstream from the microcirculation. The results support the hypothesis that VEGF contributes to hypoxic vascular remodeling through changes in abundance, organization, and function of contractile proteins.

Steroidogenesis in sheep pregnancy with intrauterine growth retardation by high-altitude hypoxia: effects of maternal altitudinal status and antioxidant treatment

Sheep pregnancy in high-altitude environments frequently involves hypoxia and oxidative stress and causes intrauterine growth retardation. The adverse effects of altitude on fetal growth can be prevented by the administration of antioxidant vitamins, but the mechanisms responsible are not well known. The maintenance of a viable pregnancy depends largely on adequate placental steroidogenesis, especially in the last two-thirds of pregnancy. Thus, in the present study we evaluated the effect of antioxidant vitamins (C and E) on plasma concentrations of progesterone and 17β-oestradiol during the last two-thirds of high-altitude pregnancies in ewes both native and naïve to the high-altitude environment. In addition, pregnancy outcomes were evaluated by determining the bodyweight of newborn lambs. Sex steroid patterns differed between ewes with and without vitamin supplementation. Concentrations of plasma progesterone and 17β-oestradiol were significantly higher in the supplemented groups from approximately 40 days before parturition until near term. Newborn weights were significantly lower in animals not adapted to the higher altitude, and vitamin supplementation prevented this decrease. In conclusion, the administration of antioxidant vitamins in the present study enhanced placental steroidogenesis, thus favouring fetal development in pregnancies developing at high altitudes.

Trends in maternal BMI, glycaemic control and perinatal outcome among type 1 diabetic pregnant women in 1989-2008

AIMS/HYPOTHESIS

Our objective was to examine the trends in prepregnancy BMI and glycaemic control among Finnish type 1 diabetic patients and their relation to delivery mode and perinatal outcome.

METHODS

We analysed the obstetric records of 881 type 1 diabetic women with a singleton childbirth during 1989-2008. Maternal prepregnancy weight and height were obtained from the maternity cards, where they are recorded as reported by the mother.

RESULTS

Maternal BMI increased significantly during 1989-2008 (p < 0.001). The mean HbA(1c) in the first trimester remained unchanged, but the midpregnancy and the last HbA(1c) before delivery increased (p = 0.009 and 0.005, respectively). Elective Caesarean sections (CS) decreased (p for trend <0.001), while emergency CS increased (p for trend <0.001). The mean umbilical artery (UA) pH decreased in vaginal deliveries (p for trend <0.001). The frequency of UA pH <7.15 and <7.05 increased (p for trend <0.001 and 0.008, respectively). The macrosomia rate remained at 32-40%. Neonatal intensive care unit (NICU) admissions increased (p for trend 0.03) and neonatal hypoglycaemia frequency decreased (p for trend 0.001). In multiple logistic regression analysis, maternal BMI was associated with macrosomia and NICU admission. The last HbA(1c) value before delivery was associated with delivery before 37 weeks' gestation, UA pH <7.15, 1 min Apgar score <7, macrosomia, NICU admission and neonatal hypoglycaemia.

CONCLUSIONS/INTERPRETATION

Self-reported pregestational BMI has increased and glycaemic control during the second half of pregnancy has deteriorated. Poor glycaemic control seems to be associated with the observed increases in adverse obstetric and perinatal outcomes.

Biomarkers of maternal diabetes and its complication in pregnancy

There are specific biomarkers - indicators of normal and abnormal processes - in diabetic pregnancies that predict the degree of diabetic control as well as embryonic and fetal growth and development. They can be detected in maternal blood, amniotic fluid or in the cord plasma of the newborn infant. While the cord plasma levels are of little clinical relevance because they do not allow us to interfere with the outcome of pregnancy, biomarkers in maternal blood or amniotic fluid may help us to better control the outcome of diabetic pregnancies. Important biomarkers in maternal blood are fasting glucose, HbA1c and IGFs. Relevant biomarkers in amniotic fluid are insulin, erythropoietin and markers of bone formation and resorption. Cord plasma biomarkers include IGFs, leptin, adiponectin, resistin, markers of oxidative stress and of hypoxia. Whether these biomarkers can be predictors of long term outcome in infants of diabetic mothers is yet to be determined.