Direct relationship of antepartum glucose control and fetal erythropoietin in human type 1 (insulin-dependent) diabetic pregnancy

Fetal monitoring technologies for the detection of intrapartum hypoxia - challenges and opportunities

Intrapartum fetal hypoxia is related to long-term morbidity and mortality of the fetus and the mother. Fetal surveillance is extremely important to minimize the adverse outcomes arising from fetal hypoxia during labour. Several methods have been used in current clinical practice to monitor fetal well-being. For instance, biophysical technologies including cardiotocography, ST-analysis adjunct to cardiotocography, and Doppler ultrasound are used for intrapartum fetal monitoring. However, these technologies result in a high false-positive rate and increased obstetric interventions during labour. Alternatively, biochemical-based technologies including fetal scalp blood sampling and fetal pulse oximetry are used to identify metabolic acidosis and oxygen deprivation resulting from fetal hypoxia. These technologies neither improve clinical outcomes nor reduce unnecessary interventions during labour. Also, there is a need to link the physiological changes during fetal hypoxia to fetal monitoring technologies. The objective of this article is to assess the clinical background of fetal hypoxia and to review existing monitoring technologies for the detection and monitoring of fetal hypoxia. A comprehensive review has been made to predict fetal hypoxia using computational and machine-learning algorithms. The detection of more specific biomarkers or new sensing technologies is also reviewed which may help in the enhancement of the reliability of continuous fetal monitoring and may result in the accurate detection of intrapartum fetal hypoxia.

The impact of maternal diabetes on birth to placental weight ratio and umbilical cord oxygen values with implications for fetal-placental development

INTRODUCTION

We determined the impact of gestational diabetes (GDM) and pre-existing diabetes (DM) on birth/placental weight and cord oxygen values with implications for placental efficiency and fetal-placental growth and development.

METHODS

A hospital database was used to obtain birth/placental weight, cord PO₂ and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA >34 weeks (N = 69,854). Oxygen saturation was calculated from the cord PO₂ and pH data, while fetal O₂ extraction was calculated from the oxygen saturation data. The effect of diabetic status on birth/placental weight and cord oxygen values was examined adjusting for covariates.

RESULTS

Birth/placental weights were stepwise decreased in GDM and DM compared to non-diabetics with placentas disproportionally larger indicating decreasing placental efficiency. Umbilical vein oxygen was marginally increased in GDM but decreased in DM attributed to the previously reported hyper-vascularization in diabetic placentas with absorbing surface area of capillaries initially increased, but then constrained by increasing distance from maternal blood within the intervillous space. Umbilical artery oxygen was unchanged in GDM and DM, with fetal O₂ extraction decreased in DM indicating that fetal O₂ delivery must be increased relative to O₂ consumption and likely due to increased umbilical blood flow.

DISCUSSION

Increased villous density/hyper-vascularization in GDM and DM with placentas disproportionately larger and umbilical blood flow increased, are postulated to normalize umbilical artery oxygen despite increased birth weights and growth-related O₂ consumption. These findings have implications for mechanisms signaling fetal-placental growth and development in diabetic pregnancies and differ from that reported with maternal obesity.

Cinnamaldehyde mitigates placental vascular dysfunction of gestational diabetes and protects from the associated fetal hypoxia by modulating placental angiogenesis, metabolic activity and oxidative stress

Gestational diabetes mellitus (GDM) is a major pregnancy-related disorder with an increasing prevalence worldwide. GDM is associated with altered placental vascular functions and has severe consequences for fetal growth. There is no commonly accepted medication for GDM due to safety considerations. Actions of the currently limited therapeutic options focus exclusively on lowering the blood glucose level without paying attention to the altered placental vascular reactivity and remodelling. We used the fat-sucrose diet/streptozotocin (FSD/STZ) rat model of GDM to explore the efficacy of cinnamaldehyde (Ci; 20 mg/kg/day), a promising antidiabetic agent for GDM, and glyburide/metformin-HCl (Gly/Met; 0.6 + 100 mg/kg/day), as a reference drug for treatment of GDM, on the placenta structure and function at term pregnancy after their oral intake one week before mating onward. Through genome-wide transcriptome, biochemical, metabolome, metal analysis and histopathology we obtained an integrated understanding of their effects. GDM resulted in maternal and fetal hyperglycemia, fetal hyperinsulinemia and placental dysfunction with subsequent fetal anemia, hepatic iron deficiency and high serum erythropoietin level, reflecting fetal hypoxia. Differentially-regulated genes were overrepresented for pathways of angiogenesis, metabolic transporters and oxidative stress. Despite Ci and Gly/Met effectively alleviated the maternal and fetal glycemia, only Ci offered substantial protection from GDM-associated placental vasculopathy and prevented the fetal hypoxia. This was explained by Ci's impact on the molecular regulation of placental angiogenesis, metabolic activity and redox signaling. In conclusion, Ci provides a dual impact for the treatment of GDM at both maternal and fetal levels through its antidiabetic effect and the direct placental vasoprotective action. Lack of Gly/Met effectiveness to restore it's impaired functionality demonstrates the vital role of the placenta in developing efficient medications for GDM.

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.

The Effect of Gestational Diabetes Mellitus on the Chorionic Villi of Human Placenta Among Saudi Arabian Mothers: A Quantitative and Comparative Study

Background The placenta is a temporary pivotal organ - the gate between the mother and the fetus. It has multiple functions such as nutrient uptake, elimination of waste products, gas exchange, and production of some vital hormones. However, the pregnancy state is a diabetogenic condition caused by insulin resistance, resulting from physiological variations. Gestational diabetes mellitus (GDM) can have an impact on both the mother and the fetus by causing numerous complications. In our research study, we aim to study and compare the quantitative effect of GDM at the microscopical level within the chorionic villi of the placenta of both mothers diagnosed with GDM and healthy mothers as well as the clinical correlation. Methods After applying the inclusion and exclusion criteria, we collected 84 placental samples from February 2017 until May 2017, which were composed of 42 GDM samples and 42 healthy samples. All of these samples have been studied under a light microscope for measuring different parameters. Results We found that some of the measured parameters among diabetic villi were lower than those of healthy villi with a p-value < .05 being significant. These include the surface area of the blood vessels (P = .008), the perimeters of the blood vessels (P = .002), the placental barrier thickness/perimeters of the villous blood vessels ratio (P ≤ .001), the placental barrier thickness/surface area of the blood vessels ratio (P ≤ .001), the number of Hofbauer cells/surface area of the villous ratio (P ≤ .001), the number of the blood vessels/surface area of the villous ratio (P = .001), the surface area of the blood vessels/surface area of the villous ratio (P = .004), and the perimeters of the blood vessels/surface area of the villous ratio (P ≤ .001). These parameters have significant effects on fetal development as well as the mother's status. Conclusions GDM is associated with multiple changes in the placenta. Moreover, these changes can impact the fetoplacental circulation and cause multiple complications for the mother and the fetus. Therefore, identifying pregnant women with GDM and controlling hyperglycemia will improve the outcomes of the pregnancy.

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.

Longer-term outcomes in offspring of GDM mothers treated with metformin versus insulin

Insulin has traditionally been the gold standard pharmacological treatment for gestational diabetes mellitus (GDM). Insulin requires multiple injections a day, can cause frequent hypoglycaemia, requires careful handling, and is generally more expensive compared to oral agents. Metformin has been increasingly popular in recent years. Based on the short-term data available, metformin appears to be safe and effective for the treatment of GDM but existing studies have all stressed the lack of longer-term offspring data. This article will analyse the evidence available on the longer-term outcomes in the offspring of women with GDM treated with metformin versus insulin. Pubmed, EMBASE, CENTRAL, and CNKI were searched for follow-up studies of randomised controlled trials that compared metformin with insulin for the treatment of GDM. Existing follow-up studies did not find any significant increase in the risk of adverse effects in terms of growth and development in the offspring of GDM mothers managed with metformin versus insulin.

HYDROCEPHALY, SCHIZENCEPHALY, SPONDYLOCOSTAL DYSPLASIA, AND HYPOPARATHYROIDISM IN AN INFANT OF A DIABETIC MOTHER

CONTEXT

Diabetes mellitus is the most frequent chronic complication in pregnancy and continues to contribute to increased perinatal morbidity and mortality in newborns. Macrosomia, respiratory distress syndrome, metabolic and electrolytic disturbances, and increased rates of congenital structural defects are well-known neonatal complications associated with maternal diabetes, even if well-controlled.

CASE REPORT

A macrosomic infant born from an insulin-dependent mother, with uncontrolled diabetes and lack of adequate prenatal care, prenatally diagnosed with hydrocephaly showed a complicated postnatal course. Initial respiratory distress syndrome and transient hypoglycemia, rapidly corrected under treatment, were followed by persistent hypocalcemia and hyperphosphatemia due to hypoparathyroidism and evolving hydrocephaly. Ventriculoperitoneal shunting was followed by resolution of hypocalcemia, but seizures associated with schizencephaly and recurrent respiratory tract infections, aggravated by spondylocostal dysplasia, concurred to infant's demise at the age of 5 months.

CONCLUSIONS

The reported case is rare due to multiple aspects: persistent hypoparathyroidism, uncommon association of schizencephaly, and even rarely association with spondylocostal dysplasia, all these conditions requiring a multidisciplinary therapeutic approach. Also, the reported case is evocative for challenges associated with infants born from diabetic mothers.

Risks of asphyxia-related neonatal complications in offspring of mothers with type 1 or type 2 diabetes: the impact of maternal overweight and obesity

AIMS/HYPOTHESIS

We aimed to compare the risks of severe asphyxia-related neonatal complications in the offspring of mothers with type 1 or type 2 diabetes, and to assess the impact of maternal overweight/obesity on these risks.

METHODS

This was a population-based study of 1,343,751 live-born singleton infants in Sweden between 1997 and 2011, including 5941 and 711 infants of mothers with type 1 and type 2 diabetes, respectively. ORs with 95% CIs were calculated for low Apgar score (0-6) at 5 min after birth, hypoxic ischaemic encephalopathy and neonatal seizures.

RESULTS

The rates of a low Apgar score were 0.9%, 2.6% and 2.1% in the offspring of mothers without diabetes or with type 1 or type 2 diabetes, respectively. After controlling for maternal confounders (including BMI), the risk of a low Apgar score increased in the offspring of mothers with type 1 diabetes (OR 2.67, 95% CI 2.23, 3.20) but not in the offspring of mothers with type 2 diabetes (OR 1.25, 95% CI 0.66, 2.35). The ORs of hypoxic ischaemic encephalopathy or neonatal seizures were increased in the offspring of mothers with type 1 diabetes (OR 3.41, 95% CI 2.58, 4.49) and type 2 diabetes (OR 2.54, 95% CI 1.13, 5.69). Maternal overweight/obesity was a risk factor for asphyxia-related neonatal complications and low Apgar scores in the offspring of mothers with type 1 diabetes and mothers without diabetes.

CONCLUSIONS/INTERPRETATION

The risks of a low Apgar score and severe asphyxia-related neonatal complications are increased in the offspring of mothers with type 1 or type 2 diabetes. Maternal overweight/obesity is an important contributing factor.

Inter-pregnancy Weight Change and Risks of Severe Birth-Asphyxia-Related Outcomes in Singleton Infants Born at Term: A Nationwide Swedish Cohort Study

BACKGROUND

Maternal overweight and obesity are associated with increased risks of birth-asphyxia-related outcomes, but the mechanisms are unclear. If a change of exposure (i.e., maternal body mass index [BMI]) over time influences risks, this would be consistent with a causal relationship between maternal BMI and offspring risks. Our objective was to investigate associations between changes in maternal BMI between consecutive pregnancies and risks of birth-asphyxia-related outcomes in the second offspring born at term.

METHODS AND FINDINGS

This study was a prospective population-based cohort study that included 526,435 second-born term (≥37 wk) infants of mothers with two consecutive live singleton term births in Sweden between January 1992 and December 2012. We estimated associations between the difference in maternal BMI between the first and second pregnancy and risks of low Apgar score (0-6) at 5 min, neonatal seizures, and meconium aspiration in the second-born offspring. Odds ratios (ORs) were adjusted for BMI at first pregnancy, maternal height, maternal age at second delivery, smoking, education, mother´s country of birth, inter-pregnancy interval, and year of second delivery. Analyses were also stratified by BMI (<25 versus ≥25 kg/m2) in the first pregnancy. Risks of low Apgar score, neonatal seizures, and meconium aspiration increased with inter-pregnancy weight gain. Compared with offspring of mothers with stable weight (BMI change of -1 to <1 kg/m2), the adjusted OR for a low Apgar score in the offspring of mothers with a BMI change of 4 kg/m2 or more was 1.33 (95% CI 1.12-1.58). The corresponding risks for neonatal seizures and meconium aspiration were 1.42 (95% CI 1.00-2.02) and 1.78 (95% CI 1.19-2.68), respectively. The increased risk of neonatal seizures related to weight gain appeared to be restricted to mothers with BMI < 25 kg/m2 in the first pregnancy. A study limitation was the lack of data on the effects of obstetric interventions and neonatal resuscitation efforts.

CONCLUSIONS

Risks of birth-asphyxia-related outcomes increased with maternal weight gain between pregnancies. Preventing weight gain before and in between pregnancies may improve neonatal health.

Increased Proportion of Hematopoietic Stem and Progenitor Cell Population in Cord Blood of Neonates Born to Mothers with Gestational Diabetes Mellitus

We assessed the hematopoietic stem and progenitor cell (HSPC) population in the cord blood of neonates born to mothers with gestational diabetes mellitus (GDM) in a hypothesis generating pilot study, due to that, neonatal polycythemia may be the consequence of GDM pregnancy. Forty-five pregnant women with GDM (last trimester mean HbA1C = 33.9 mmol/mol) and 42 (nondiabetic) control pregnant women were enrolled after their routine 75 g oral glucose tolerance test (OGTT) between the 24th and 28th gestational week (with expected differences in their mean routine clinical characteristics: plasma glucose at OGTT: 0′ = 5.07 vs. 4.62 mM, 120′ = 8.9 vs. 5.76 mM, age = 35.07 vs. 31.66 years, prepregnancy body mass index = 27.9 vs. 23.9 kg/m², GDM vs. control, respectively) on a voluntary basis after signing the informed consent. EDTA-treated cord blood samples were analyzed by flow cytometry and the software Kaluza1.2 using CD45 and CD34-specific fluorescent antibodies to identify the HSPC population (CD34⁺ cells within the CD45^dim blast gate). The proportion of CD34⁺CD45^dim HSPCs among the nucleated cells was significantly (P < 0.05, statistical power = 60.8%) higher in the cord blood samples of neonates born to mothers with GDM (median 0.38%) compared to neonates born to nondiabetic mothers (median 0.32%) and according to treatment types (P < 0.05) median: control 0.32%, GDM-diet only 0.37%, GDM-on insulin 0.45%; control versus GDM on insulin (P < 0.05). The increased proportion of circulating CD34⁺CD45^dim cells in the cord blood may possibly be related to altered fetal stem cell mobilization in GDM pregnancy, yet these results should be interpreted only as preliminary due to the small sample sizes.

Amniotic fluid erythropoietin and neonatal outcome in pregnancies complicated by intrauterine growth restriction before 34 gestational weeks

OBJECTIVE

High amniotic fluid erythropoietin concentration reflects chronic fetal hypoxia. Our aim was to study amniotic fluid erythropoietin concentration in relation to neonatal outcome in pregnancies complicated by intrauterine growth restriction.

DESIGN

Retrospective case series.

SETTING

Helsinki University Hospital, Finland.

SAMPLE

A total of 66 singleton pregnancies complicated by intrauterine growth restriction.

METHODS

Amniocentesis or amniotic fluid sampling at cesarean section was performed between 24 and 34 gestational weeks. Values of amniotic fluid erythropoietin were quantitated with immunochemiluminometric assay. Normal amniotic fluid erythropoietin was defined as <3 IU/L, intermediate as 3-27 IU/L, and abnormal as >27 IU/L.

MAIN OUTCOME MEASURES

Adverse neonatal outcome.

RESULTS

Abnormal biophysical profile and reversed end-diastolic flow in umbilical artery were associated with abnormal amniotic fluid erythropoietin (p < 0.001 and p = 0.042, respectively). Abnormal amniotic fluid erythropoietin was not associated with absent end-diastolic flow in umbilical artery or with oligohydramnios (p = 0.404 and p = 0.080, respectively). Decreased umbilical artery pH and base excess values were associated with abnormal amniotic fluid erythropoietin (p = 0.027 and p = 0.007, respectively). Composite adverse neonatal outcome defined as intraventricular hemorrhage, periventricular leukomalacia, cerebral infarction and/or necrotizing enterocolitis was associated with abnormal amniotic fluid erythropoietin (p < 0.001).

CONCLUSIONS

High amniotic fluid erythropoietin concentrations are associated with decreased umbilical artery pH and base excess and with adverse neonatal outcome in pregnancies complicated by intrauterine growth restriction before 34 gestational weeks. In selected pregnancies complicated by intrauterine growth restriction, determining amniotic fluid erythropoietin could be a useful additional tool in fetal surveillance and possibly in optimizing timing of delivery.

Anaemia, a common but often unrecognized risk in diabetic patients: a review

Anaemia in patients with diabetes, both type 1 and type 2, is a frequent clinical finding. The mechanisms of anaemia are multifactorial and often not very well understood. Iatrogenic causes, including oral antidiabetic drugs, ACE inhibitors and ARBs, and renal insufficiency are the major causes of anaemia in patients with type 2 diabetes. In patients with type 1, the cause is often an associated autoimmune disease, and screening for autoimmune gastritis, pernicious anaemia, Hashimoto's thyroiditis, coeliac disease and Addison's disease is recommended. Other rare causes - including G6PD deficiency, microangiopathic haemolytic anaemia and thiamine-responsive megaloblastic anaemia - should be suspected in young patients or when the classical causes are excluded. Early detection and recognition of the cause(s) of anaemia in patients with diabetes could help to prevent other clinical manifestations as well as the complications of diabetes.

Amniotic fluid oxidative and nitrosative stress biomarkers correlate with fetal chronic hypoxia in diabetic pregnancies

BACKGROUND

In spite of improvement in obstetrical care, pregnancy in women with type 1 diabetes mellitus is associated with increased perinatal morbidity and mortality. Hyperglycemia during pregnancy causes excessive fetal growth and chronic fetal hypoxia as reflected in increased erythropoietin (EPO) levels in amniotic fluid (AF).

OBJECTIVES

We hypothesized that the degree of fetal hypoxia would correlate with fetal oxidative and nitrosative stress as evidenced ty the concentration of specific biomarkers in AF.

MATERIAL AND METHODS

19 pregnant women with type 1 or insulin-treated gestational diabetes mellitus were studied. AF samples were collected and processed for EPO, meta-tyrosine, nitro-tyrosine and 8-hydroxy-2-deoxiguanosine by chemiluminescent immunoassay and high-performance liquid chromatography coupled to tandem mass spectrometry methods, respectively.

RESULTS

The mean (SD) of the last HbA1c concentration before delivery was 7.7% (1.1). Median gestational age was 258 days (range 231-268). Birth weight was 3,868 ± 695 g with a z-score >2 SD in 47% of the cases. A significant correlation was found between the concentrations of AF EPO and meta-tyrosine/phenylalanine ratio (p < 0.001), nitro-tyrosine (p < 0.01) and 8-oxo-dG/2dG ratio (p < 0.001).

CONCLUSIONS

We confirmed that fetuses of type 1 diabetes or insulin-treated gestational diabetes pregnancies experience chronic hypoxia as reflected by increased EPO concentrations in AF near term. Moreover, EPO levels significantly correlated with the concentration of oxidative and nitrosative stress biomarkers in AF. This pro-oxidant status may predispose newborn infants to poor postnatal adaptation and early neonatal complications.

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.

Are the neonatal outcomes similar in large-for-gestational age infants delivered by women with or without gestational diabetes mellitus?

BACKGROUND

Infants are considered large for gestational age (LGA) if their birth weight is greater than the 90th percentile for gestational age and they have an increased risk for adverse perinatal outcomes. Maternal diabetes is one of the factors affecting birthweight. However there are limited data on the perinatal outcomes of infants of gestational diabetic mothers. The aim of the present study was to compare the neonatal outcomes of LGA infants delivered by women with and without gestational diabetes mellitus.

METHODS

This was a retrospective study of LGA infants of ≥36 weeks of gestation born at the Gazi University Medical School Hospital during the period of 2006-2009. Neonatal outcomes included hypoglycemia and polycythemia in the early neonatal period and hospital admissions. The Chi-square and Student's t test were used for comparing variables.

RESULTS

Seven hundred eligible infant-mother pairs were enrolled in the study. Eighty-seven of them (12.4%) were infants of gestational diabetic mothers and 613 (87.6%) were infants of non-diabetic mothers. The incidence of hypoglycemia at the first hour was higher in infants of diabetic mothers (12.8%) than in infants of non-diabetic mothers (5.3%) (P=0.014). Polycythemia was also more frequently observed in infants of the gestational diabetic mothers (9.3%) than in infants of the non-diabetic mothers (3.0%) (P=0.010). Although overall hospital admission rates were not different between the two groups, infants of diabetic mothers were more likely to be admitted because of resistant hypoglycemia (P=0.045).

CONCLUSIONS

The results of this study suggested that LGA infants of mothers with gestational diabetes mellitus were at a greater risk for hypoglycemia and polycythemia in the early neonatal period than LGA infants of nondiabetic mothers.

Foetal and neonatal complications in gestational diabetes: perinatal mortality, congenital malformations, macrosomia, shoulder dystocia, birth injuries, neonatal complications

OBJECTIVE

To evaluate the risks of perinatal complications in infants born to mothers with treated or untreated gestational diabetes mellitus (GDM).

METHODS

A search of the PubMed database was performed and recommendations from NICE and the French National Authority for Health were consulted.

RESULTS

Untreated moderate or severe GDM increases the risk of foetal and neonatal complications (EL1). The risk of malformations slightly increases in newborns of mothers with GDM compared to the general population (EL2). This risk is probably associated with the presence of undiagnosed type 2 diabetes among patients with GDM (EL2). There is a linear relationship between maternal blood glucose levels and an increased birth weight (EL2). Treatment for GDM reduces the incidence of macrosomia (EL1). Although the risk of cardiomyopathy in cases of GDM cannot be accurately estimated based on the available data, severe clinical forms are rare. The risks of neonatal asphyxia and perinatal mortality are no higher in infants born to women with GDM (EL2). Birth injuries and brachial plexus injuries are rare, and no more likely to occur in cases of untreated GDM. It is difficult to assess the risk of respiratory distress, regardless of its cause. It is not possible to establish a link between GDM and neonatal respiratory problems due to insufficient data. Although the risk of neonatal hypoglycaemia is difficult to determine due to the variable definitions reported in the literature, the incidence of hypoglycaemia requiring intravenous therapy is low (EL1). The risks of hypocalcaemia (EL4) and hyperbilirubinemia (EL1) are similar to the general population.

CONCLUSION

Serious perinatal complications specifically associated with GDM are rare. Macrosomia has been demonstrated to be the predominant adverse outcome in cases of GDM. It is the main factor linked to reported cases of complications in GDM. Maternal obesity is an additional risk factor for complications, regardless of diabetes status.

Stillbirth in diabetic pregnancies

Pregnancy in women with pregestational diabetes is associated with high perinatal morbidity and mortality. Stillbirth accounts for the majority of cases with perinatal death. Intrauterine growth restriction, pre-eclampsia, foetal hypoxia and congenital malformations may be contributing factors, but more than 50% of stillbirths are unexplained. Majority of stillbirths are characterised by suboptimal glycaemic control during pregnancy. Foetal hypoxia and cardiac dysfunction secondary to poor glycaemic control are probably the most important pathogenic factors in stillbirths among pregnant diabetic women. There is thus a need for new strategies for improving glycaemic control to near-normal levels throughout pregnancy and for preventing and treating hypertensive disorders in pregnancy. Antenatal surveillance tests including ultrasound examinations of the foetal growth rate, kick counting and non-stress testing of foetal cardiac function are widely used. However, future research should establish better antenatal surveillance tests to identify the infants susceptible to stillbirth before it happens.

Obstetric problems in diabetic pregnancy - The role of fetal hypoxia

Perinatal mortality has not decreased over the last two decades in pregestational diabetic pregnancies. Stillbirth rate is 4-6 times and neonatal mortality 2-4 times higher in diabetic than in non-diabetic pregnancies despite modern electronic fetal surveillance methods. Majority of late stillbirths are "unexplained", many of which are presumably caused by fetal hypoxia. Both experimental and clinical studies have shown that fetal hyperglycaemia and hyperinsulinaemia can independently cause fetal hypoxia, which ultimately can lead to fetal death. Poor glycaemic control is associated with perinatal complications. Sharp increases in amniotic fluid erythropoietin levels indicate fetal hypoxia in diabetic pregnancy. Fetal erythropoietin concentrations correlate directly with maternal HbA(1c) levels. It is therefore important to maintain near-normal glycaemic level throughout pregnancy. Measurement of amniotic fluid erythropoietin level is a new way to detect fetal hypoxia antenatally. Sufficiently large controlled studies are needed before definitive answer of the clinical utility of amniotic fluid erythropoietin measurements in diabetic pregnancies can be determined.

Erythrocytosis in offspring of mothers with Type 1 diabetes--are factors other than insulin critical determinants?

AIM

Maternal diabetes is associated with polycythaemia and thrombocytopaenia in the offspring; however, the relationship with fetal hormones is unknown. We assessed the association of maternal glycaemic control, birthweight and fetal hormones with haematological indices in pregnancies complicated by maternal diabetes.

METHODS

Prospective study using cord blood samples from 89 offspring of mothers with Type 1 diabetes (OT1DM) and 34 control offspring. Full blood count, insulin, leptin, adiponectin, cortisol, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3, intercellular adhesion molecule 1 and C-reactive protein were measured in the umbilical vein at birth.

RESULTS

Haematocrit was higher in OT1DM (OT1DM 0.55 +/- 0.17%, control offspring 0.51 +/- 0.06%; P = 0.02). The difference in platelets count was not statistically significant [OT1DM 214 x 10(9)/l (173-259); control offspring 253 x 10(9)/l (180-310), P = 0.06]. Maternal glycated haemoglobin (HbA(1c)) showed a moderate positive correlation with fetal haematocrit (r = 0.30, P = 0.02). Cord platelet counts were negatively associated with birthweight in OT1DM (r = -0.27, P = 0.01). In multivariate models, cord insulin was not associated with haematocrit, but cord leptin was negatively associated with platelets in control offspring (P < 0.001) and OT1DM (P = 0.046), with additional contributions from male sex (P = 0.08) in OT1DM, and IGF-1 (P = 0.04) and insulin (P = 0.04) in control offspring.

CONCLUSIONS

Fetal haematocrit is increased in response to diabetes in pregnancy and is related to maternal glycaemic control. Fetal hyperinsulinism, hyperleptinaemia or macrosomia, although readily demonstrable in this cohort, do not emerge as determinants of raised fetal haematocrit in OT1DM. Both increased birthweight and fetal leptin are negatively associated with platelet count.

Fetal and embryonic hemoglobins in erythroblasts from fetal blood and fetal cells enriched from maternal blood in pregnancies complicated by maternal diabetes mellitus

OBJECTIVES

To determine whether there is a delay or reversal in switch mechanisms from embryonic (epsilon and zeta) to fetal (gamma) hemoglobins accompanying the erythroblastosis in fetuses of diabetic mothers, and whether the increased erythroblast count in the fetal blood is associated with an increase in fetomaternal cell trafficking.

MATERIALS AND METHODS

Fetal and maternal blood samples were obtained from 11 fetuses and five pregnant women in pregnancies complicated by maternal diabetes mellitus. Blood samples were also taken as controls from 35 fetuses and 33 mothers. Fetal erythroblasts were isolated by triple density gradient centrifugation and magnetic cell sorting with anti-CD71 antibody. Fluorescent antibodies were used to immunostain for gamma (gamma), epsilon (epsilon) and zeta (zeta) hemoglobin chains. In the maternal samples, fluorescence in situ hybridization for X and Y chromosomes was also carried out, to confirm the presence and proportion of enriched fetal cells from the maternal blood.

RESULTS

In both fetal and maternal blood the median percentages of erythroblasts positive for gamma-globin, epsilon-globin and zeta-globin chains were significantly higher in fetuses of diabetic mothers compared to controls (fetus, gamma-globin, 76 vs. 64%, p < 0.0001; epsilon-globin, 4 vs. 0%, p < 0.0001; zeta-globin, 4 vs. 0%; p < 0.0001; mother, gamma-globin, 14 vs. 1%, p < 0.0005; epsilon-globin, 0.25 vs. 0%, p < 0.0003; zeta-globin, 0.2 vs. 0%, p < 0.0003). The median percentage of cells with Y signals in maternal blood was also higher in diabetic pregnancies compared to normal controls (7.5 vs. 1%, p < 0.002).

CONCLUSIONS

The findings suggest that the fetal erythroblastosis in diabetic pregnancies is accompanied by a delay in the switch from embryonic to fetal hemoglobin chains. In addition, it is associated with an increase in fetomaternal cell trafficking.

TYPE 1 DIABETES IN PREGNANCY; INFLUENCES ON MOTHER AND FETUS

Type 1 diabetes complicates around 1 in 200 to 300 pregnancies in the United Kingdom. Historically maternal type 1 diabetes carried very high risks for mother and child. Introduction of insulin led to an immediate, marked decline in the previously very high rates of maternal mortality; in contrast an improvement in perinatal outcomes occurred more slowly but was nevertheless dramatic. This is strikingly demonstrated by the temporal decline in perinatal mortality in offspring of mothers with type 1 diabetes which was virtually universal before use of insulin in the 1920's, likely remained in excess of 20% even in the 1960's and fell to under 4% by the 1990's. The reasons for this more gradual improvement in perinatal outcomes cannot be defined with precision but will have been influenced by improved glycaemic management with use of intensive, multiple dose insulin treatment and home glucose monitoring; improvements in obstetric and neonatal management, and better management of complications of diabetes before and during pregnancy. In 1989 the St Vincent declaration proposed that pregnancy outcomes in women with type 1 diabetes should approximate those of the non-diabetic population. While the long term improvements in fetal outcomes have been dramatic, contemporary surveys confirm a persistent doubling or more of rates of congenital anomaly and a three to four fold increase in perinatal mortality in the UK and other European countries which will require further clinical innovation to overcome.

Amniotic fluid S100B protein and erythropoietin in pregnancies at risk for fetal hypoxia

OBJECTIVE

S100B protein is a biochemical marker for brain injury, and high serum S100B levels have been observed in newborns with birth asphyxia. We hypothesized that the concentration of amniotic fluid erythropoietin, which increases in chronic fetal hypoxia, correlates with amniotic fluid S100B concentration.

STUDY DESIGN

Amniotic fluid samples in 35 pregnancies at high risk for chronic fetal hypoxia were obtained at cesarean section or by amniocentesis done within a median of 2 days before delivery. S100B and erythropoietin concentrations were measured by chemiluminescent immunoassays.

RESULTS

A positive correlation existed between the concentrations of S100B and erythropoietin in the amniotic fluid (r=0.57, p<0.0001). Amniotic fluid S100B concentration was higher (70 ng/l; 33-469, n=17) (median; range) in pregnancies with elevated amniotic fluid erythropoietin (>or= 50 IU/l) than in pregnancies with normal erythropoietin (34 ng/l; 20-340, n=18) (p<0.0001, Mann-Whitney U-test). S100B predicted an elevated amniotic fluid erythropoietin concentration in the study population with the sensitivity of 94% and specificity of 83%.

CONCLUSION

A strong positive correlation exists between amniotic fluid S100B and erythropoietin concentrations in pregnancies at high risk for chronic fetal hypoxia. This suggests that chronic fetal hypoxia increases the intrauterine release of S100B.

Increased fetal plasma and amniotic fluid erythropoietin concentrations: markers of intrauterine hypoxia

Tissue hypoxia is the major stimulus of erythropoietin (EPO) synthesis in fetuses and adults. Since EPO does not cross the placenta and is not stored, fetal plasma and amniotic fluid levels indicate EPO synthesis and elimination. Acutely, the rate and magnitude of the increase in plasma EPO levels correlate with the intensity of hypoxia. Amniotic fluid EPO levels correlate with cord plasma levels in normal and abnormal pregnancies, with fetal plasma EPO levels in humans averaging 2.6 times higher than the corresponding amniotic fluid EPO levels. Recent experimental and clinical studies demonstrate that EPO has neuroprotective effects related to its anti-apoptotic and vascular growth-promoting properties. Although under basal conditions the fetal kidneys are the main site of EPO production, during hypoxia recent experimental data indicate an important role of the placenta. Amniotic fluid EPO levels have been shown to increase exponentially during fetal hypoxia in preeclamptic, diabetic and Rh-immunized pregnancies, to correlate inversely with cord blood pH, pO(2) and base excess and to predict neonatal morbidities and NICU admission. As an indicator of chronic intrauterine hypoxia, fetal EPO measurements have increased our knowledge about the pathogenesis and importance of intrauterine growth restriction, macrosomia, diabetic pregnancy, prolonged pregnancy, meconium staining, fetal hemorrhage, fetal anemia, maternal smoking and alcohol consumption, abnormal fetal heart rate and abnormal Doppler flow patterns. While the clinical utility of fetal amniotic fluid and plasma EPO measurements in the management of high-risk pregnancies and their offspring is promising, adequately powered clinical trials are urgently needed.

Morphometric study of placental villi and vessels in women with mild hyperglycemia or gestational or overt diabetes

In this study, morphometric measures of placental terminal villi and villous vessels were compared in overt, as well as gestational diabetes mellitus, and mild hyperglycemia diagnosed by oral 100 g glucose tolerance test (100 g-OGTT) and glucose profile (GP). At delivery (gestational age> or =34 weeks) a total of 207 placentas were assigned to a control group (n=56) or to one of three groups complicated by mild hyperglycemia (n=51), gestational diabetes (n=59) and overt diabetes (n=41). Placenta samples were randomly selected for blind morphometric assessment with an image analyser. Morphometric measures obtained included area and number of terminal villi and their respective villous vessels. Statistical analyses were performed using the chi-square test, ANOVA and stepwise regression (p< or =0.05). Glycemic means were 86.2 mg/dL in controls, 98.9 mg/dL in mild hyperglycemia, 114.1 mg/dL in gestational diabetes and 122.1 mg/dL in overt diabetes. Our results show that abnormal maternal glycemic levels may change the placental morphometric characteristics related to materno-fetal exchanges.

Elevated zinc protoporphyrin/heme ratios in umbilical cord blood after diabetic pregnancy

OBJECTIVE

Offspring of diabetes patients may suffer from tissue iron deficiency. Erythrocyte zinc protoporphyrin/heme (ZnPP/H) ratios measure impaired iron status. The aim of the study was to examine whether cord ZnPP/H ratios were associated with pregnancy glycemic control.

METHODS

ZnPP/H was measured in cord blood from 31 pregnancies with insulin-treated diabetes (diabetes group) and compared to population normal values. Maternal glycemic control was assessed by daily glucose log, glycosylated hemoglobin and birth weight.

RESULTS

Median cord ZnPP/H was higher in the diabetes group than the population normal values (106 (65.2 to 146.8) microM/M vs 68.2 (37.6 to 98.8) micro/M, P < 0.0001). Ratios were directly correlated to surrogates of control (glycosylated hemoglobin, P = 0.05, and birth weight, P < 0.04). Cord ZnPP/H ratios from pregnancies with pre-existing and gestational diabetes were similar.

CONCLUSION

Because cord ZnPP/H was higher in large offspring of diabetic pregnancy, it might identify greater iron utilization for fetal erythropoiesis.

High amniotic fluid erythropoietin levels are associated with an increased frequency of fetal and neonatal morbidity in type 1 diabetic pregnancies

AIMS/HYPOTHESIS

In this study we investigated whether chronic fetal hypoxia, as indicated by amniotic fluid erythropoietin levels, is associated with perinatal morbidity in type 1 diabetic pregnancies.

METHODS

A total of 331 women with type 1 diabetes had at least one childbirth between 1995 and 2000. The amniotic fluid erythropoietin concentration was measured in 156 diabetic singleton pregnancies at a median time of 1 day before Caesarean section without labour contractions and in 19 healthy control subjects at Caesarean section.

RESULTS

The median amniotic fluid erythropoietin level was 14.0 mU/ml (range 2.0-1975.0) in diabetic pregnancies and 6.3 mU/ml (range 1.7-13.7) in controls (p<0.0001). Of the 156 diabetic patients, 21 (13.5%) had amniotic fluid erythropoietin levels higher than 63.0 mU/ml. Amniotic fluid erythropoietin levels correlated negatively with umbilical artery pH (r=-0.49, p<0.0001) and pO2 (r=-0.62, p<0.0001) at birth and neonatal lowest blood glucose level (r=-0.47, p<0.0001). Positive correlations were found between amniotic fluid erythropoietin levels and umbilical artery pCO2 (r=0.49, p<0.0001) and last maternal HbA1c (r=0.43, p<0.0001). Furthermore, a U-shaped correlation was demonstrated between amniotic fluid erythropoietin levels and birthweight z score (z score below -0.6 SD units: r=-0.63, p=0.0007; z score above +1.0 SD units: r=0.32, p=0.0014). Neonatal hypoglycaemia, hypertrophic cardiomyopathy and admission to the neonatal intensive care unit occurred significantly more often in cases with high amniotic fluid erythropoietin levels (>63.0 mU/ml) than in those with normal levels. Multivariate logistic regression analysis revealed that amniotic fluid erythropoietin was the only variable independently related to low umbilical artery pH (<7.21; p<0.0001) and neonatal hypoglycaemia (p=0.002). Low umbilical artery pO2 (<15.0 mm Hg) was explained by amniotic fluid erythropoietin (p<0.0001) and birthweight z score (p=0.004).

CONCLUSIONS/INTERPRETATION

Antenatal high amniotic fluid erythropoietin levels can identify type 1 diabetic pregnancies at increased risk of severe perinatal complications.

Amniotic fluid and cord plasma erythropoietin levels in pregnancies complicated by preeclampsia, pregnancy-induced hypertension and chronic hypertension

AIMS

The purpose of the present study was to compare fetal and neonatal outcomes with amniotic fluid erythropoietin (EPO) levels obtained in the antepartum period in pregnancies complicated by preeclampsia, pregnancy-induced hypertension or chronic hypertension.

METHODS

Erythropoietin concentrations were measured in amniotic fluid within 2 days before delivery and in cord blood at birth in 75 hypertensive women and in 23 healthy controls delivered by cesarean section before labor contractions. Erythropoietin levels did not influence clinical decisions.

RESULTS

Amniotic fluid erythropoietin levels correlated highly significantly with cord plasma EPO levels and were significantly higher in pregnancies complicated by hypertension than in control pregnancies. Umbilical arterial pH, acid-base and blood gas values at birth were not different from controls. Both cord plasma and amniotic fluid erythropoietin levels correlated with cord blood pH, acid-base and blood gas values at birth in the study group. Newborn infants admitted to the newborn intensive care unit had significantly higher fetal erythropoietin levels and were more acidotic, hypoxemic and hypoglycemic than infants admitted to the normal care nursery.

CONCLUSIONS

Our findings suggest that elevated amniotic fluid erythropoietin levels are markers of chronic or subchronic fetal hypoxia and are associated with neonatal morbidity in pregnancies complicated by hypertension.

Hyperinsulinemia may boost both hematocrit and iron absorption by up-regulating activity of hypoxia-inducible factor-1α

There is growing evidence that increases in both hematocrit and body iron stores are components of the insulin resistance syndrome. The ability of insulin and of IGF-I - whose effective activity is increased in the context of insulin resistance - to boost activity of the transcription factor hypoxia-inducible factor-1alpha (HIF-1alpha), may be at least partially responsible for this association. HIF-1alpha, which functions physiologically as a detector of both hypoxia and iron-deficiency, promotes synthesis of erythropoietin, and may also mediate the up-regulatory impact of hypoxia on intestinal iron absorption. Insulin/IGF-I may also influence erythropoiesis more directly, as they are growth factors for developing reticulocytes. Conversely, the activation of HIF-1alpha associated with iron deficiency may be responsible for the increased glucose tolerance noted in iron-deficient animals; HIF-1alpha promotes efficient glucose uptake and glycolysis - a sensible adaptation to hypoxia - by inducing increased synthesis of glucose transporters and glycolytic enzymes. Recent reports that phlebotomy can increase the efficiency of muscle glucose uptake in lean healthy omnivores are intriguing and require further confirmation. Whether increased iron stores contribute to the elevated vascular risk associated with insulin resistance is doubtful, inasmuch as most prospective studies fail to correlate serum ferritin or transferrin saturation with subsequent vascular events. However, current data are reasonably consistent with the possibility that moderately elevated iron stores are associated with increased overall risk for cancer - and for colorectal cancer in particular; free iron may play a catalytic role in 'spontaneous' mutagenesis. Thus, iron excess may mediate at least some of the increased cancer risk associated with insulin resistance and heme-rich diets. People who are insulin resistant can minimize any health risk associated with iron overload by avoiding heme-rich flesh foods and donating blood regularly.

Stereological comparison of 3D spatial relationships involving villi and intervillous pores in human placentas from control and diabetic pregnancies

In human placenta, 3D spatial relationships between villi and the maternal vascular bed determine intervillous porosity and this, in turn, influences haemodynamics and transport. Recently-developed stereological methods were applied in order to examine and quantify these relationships. Placentas were collected after 37 wk from control pregnancies and those associated with maternal diabetes mellitus classified according to duration and severity (White classification scheme). Two principal questions were addressed: (1) are normal spatial arrangements maintained in well-controlled diabetes mellitus? and (2) do arrangements vary between diabetic groups? To answer these questions, tissue sections cut at random positions and orientations were generated by systematic sampling procedures. Volume densities of villi (terminal + intermediate), intervillous spaces and perivillous fibrin-type fibrinoid deposits were estimated by test point counting and converted to global volumes after multiplying by placental volumes. Design-based estimates of the sizes (volume- and surface-weighted volumes) of intervillous 'pores' were obtained by measuring the lengths of point- and intersection-sampled intercepts. From these, theoretical numbers of pores were calculated. Model-based estimates (cylinder model) of the hydraulic diameters and lengths of pores were also made. Second-order stereology was used to examine spatial relationships within and between villi and pores and to test whether pair correlation functions deviated from the value expected for 'random' arrangements. Estimated quantities did not differ significantly between diabetic groups but did display some departures from control values in non-insulin-dependent (type 2) diabetic placentas. These findings support earlier studies which indicate that essentially normal microscopical morphology is preserved in placentas from diabetic subjects with good glycaemic control. Therefore, it is likely that fetal hypoxia associated with maternal diabetes mellitus is due to metabolic disturbances rather than abnormalities in the quantities or arrangements of maternal vascular spaces.

Effects of diabetic pregnancy on the fetus and newborn

Diabetes in pregnancy is unique because of the diversity of problems that can affect the embryo/fetus beginning with conception. Considerable effort has been devoted to understanding the basic developmental biology from observing young embryos in vitro or in vivo. Maternal glucose control has been identified as an important event. The preponderance of evidence indicates that rigid glucose control will minimize the incidence of anomalies incurred before 9 weeks of pregnancy. Later events are related to fetal hyperinsulinemia. These include fetal macrosomia, respiratory distress syndrome, neonatal hypoglycemia, neonatal hypocalcemia, and neonatal hypomagnesemia. Control of maternal metabolism can have a significant impact on each of the above. Finally, the long-term effects of maternal diabetes are as diverse as the pathogenetic events during pregnancy. Surprisingly, there is a significant transmission rate of 2% of type I diabetes if the mother has insulin-dependent diabetic mother, whereas the rate is 6% for the father. The Diabetes in Early Pregnancy Study showed that good maternal control was associated with normal neurodevelopmental outcome.

Quantitative studies on the villi, trophoblast and intervillous pores of placentae from women with well-controlled diabetes mellitus

Human placentae from well-controlled diabetic women were collected after 37 weeks of gestation and divided into three groups according to the duration and severity of diabetes mellitus established by White classification criteria. A fourth group of subjects served as matched controls. Various morphometric variables not estimated hitherto (including the star volumes of villous 'domains' and intervillous 'pores' and trophoblast surface denudation) were assessed stereologically. The aims were to test whether or not (1) control values of these structural quantities are preserved in well-controlled diabetes mellitus, and (2) differences occurred between alternative diabetic groups. Placental specimens were obtained by systematic random sampling procedures and paraffin sections were cut at random positions and orientations. Volume densities of peripheral (terminal+intermediate) villi and intervillous spaces were estimated by test point counting and multiplied by placental volumes in order to convert them into absolute volumes. Volume estimates were also obtained for trophoblast, syncytiotrophoblast nuclei and intervillous fibrin-type fibrinoid. Villous surface areas were estimated by intersection counting and the star volumes of villi and intervillous pores were obtained by measuring the lengths of point-sampled intercepts. Calculations were also made of the theoretical numbers of villous domains and intervillous pores and of the numbers of syncytiotrophoblast nuclei. No significant differences were detected between control and diabetic placentae, or between White classes, for any of the estimated quantities. It is concluded that normal values are preserved by good glycaemic control regardless of diabetic grouping.

Erythropoietin in amniotic fluid as a marker of chronic fetal hypoxia

OBJECTIVE

To determinate the erythropoietin concentration in amniotic fluid in normal pregnancies and pregnancies with suspected hypoxia.

METHOD

The erythropoietin concentration of 164 samples of amniotic fluid was determined by ELISA. The samples were taken by amniotomy during birth, as well as amniocentesis conducted during prenatal care.

RESULTS

A distribution of 1.07-7.29 U/l (10th-90th percentile) within the normal group (n = 106) was determined. Significantly elevated erythropoietin levels in amniotic fluid were determined in maternal hypertension (P = 0.039) and low birth-weight children (P = 0.0032). A correlation with the child's sex could be excluded.

CONCLUSION

Elevated erythropoietin levels in amniotic fluid indicated chronic fetal hypoxia.

The infant of the diabetic mother

The history of the medical success in treatment of the pregnant diabetic woman and her infant in the twentieth century illustrates how the combined efforts of dedicated clinicians and researchers have resulted in dramatic improvements in outcome for this patient group. This article discusses fetal growth, metabolic complications of the infant of the diabetic mother, risk of respiratory distress syndrome, hypertrophic cardiomyopathy, and congenital anomalies.

The ontogeny of the biological role and production of erythropoietin

In has been long recognized that erythropoiesis in adults is under control of erythropoietin, a glycoprotein produced mainly by adult kidneys in inverse relation to oxygen availability. Increasing evidence indicates nowadays that EPO is also an essential growth factor for red cell precursors at different sites of fetal erythropoiesis. The primary site of EPO production during fetal and neonatal life is the liver, and the fetus has been shown to be able to increase EPO production in response to hypoxia through intrinsic oxygen sensing mechanisms of hepatocytes. Thus despite different sites of both erythropoiesis and EPO production a similar oxygen dependent feedback control of red cell formation appears to operate during all stages of development. EPO levels in fetal blood are potentially useful parameters of fetal stress, and, as in adults, the availability of recombinant EPO raises the possibility to modulate erythropoiesis in the perinatal period.

Response to repeated phlebotomies in patients with non-insulin-dependent diabetes mellitus

Regardless of type, uncontrolled diabetes represents a serious disruption of fuel homeostasis with consequences throughout the body. This may hamper the applicability of predeposited autologous blood transfusion in diabetic patients because metabolic changes are expected as a consequence of repeated bleeding. We undertook this study to determine whether the presence of non-insulin-dependent diabetes mellitus (NIDDM) influences the erythropoietin (EPO) response to repeated phlebotomies with respect to normal subjects. We included 22 consecutive patients scheduled for major surgery during a 2-year period in which clinical and metabolic complications were excluded and renal and liver function was considered unaffected. Selected biochemical and hematologic variables were serially measured during donation of several units of blood in a 12- to 29-day period. Bleeding produced a significant decrease in serum glucose, cholesterol, triglyceride, and apoprotein B concentration in diabetic patients. Except for glucose, this effect was not observed in controls. Both groups were comparable with respect to initial hemoglobin concentrations and all hematologic variables measured. The decrease in hemoglobin concentration did not produce clinical symptoms in these patients, and recovery was regarded as normal in both groups. Serum EPO levels in diabetic patients were negatively influenced by the initial hemoglobin A1c (HbA1c) proportion. Moreover, three nonrespondent diabetic patients with poor glycemic control responded normally 6 to 13 months later, in a second operation, when glycemic control had improved significantly. In conclusion, NIDDM may limit the donation of requested units for major surgery only if poor glycemic control is present. When possible, phlebotomies should be delayed and metabolic control reinforced.

Oxygen diffusive conductance in placentae from control and diabetic women

Random tissue sections of placentae from control and diabetic deliveries were analysed stereologically. The aim was to test whether or not adaptations in oxygen diffusive conductances occur to help compensate for fetal hypoxic stress in utero. Organs were from 34 control and 55 diabetic deliveries (39 from White's classes A, B, C and 16 from classes D, F/R) arranged in two major groups (ABC and DFR). Tissue samples were fixed in formalin and processed for wax histology. Stereological and physicochemical quantities were used to calculate the partial conductances of six tissue layers, viz. maternal erythrocytes and plasma, villous trophoblast, villous stroma, fetal plasma and fetal erythrocytes. From partial conductances and birthweights, total and specific conductances for each placenta were determined. No differences were detected between diabetic placentae in different classes (A, B, C, D, F/R). However, both the ABC and DFR groups of diabetic placentae had higher total diffusive conductances than control organs. The increase was in the order of 7-25% and persisted even when adjustments were made for apparent differences in birthweights. The principal contributors to these changes were the post-trophoblastic (fetally located) tissue layers. These findings suggest that the diabetic placenta adapts to facilitate the diffusion of oxygen across the placenta and, thereby, to assist the hypoxic fetus.

Prenatal diagnosis of familial neonatal hyperinsulinemia

A kindred with familial neonatal hyperinsulinemia is described. Infant A was macrosomatic and stillborn. Infant B was macrosomatic at birth following a pregnancy uncomplicated by maternal diabetes. Following diagnosis of hyperinsulinemic hypoglycemia, this patient was treated with oral diazoxide. Therapy continued until hyperinsulinemia resolved by two years of age. Based on this history, the pregnancy with infant C was intensively monitored using ultrasonography and amniocentesis. Insulin and C-peptide concentrations in amniotic fluid were markedly increased compared to control pregnancies. Based on these results, infant C was delivered immediately upon obtaining evidence of lung maturation. Neonatal hyperinsulinemia was confirmed by a markedly increased cord plasma insulin concentration. Based on our experience, we recommend that insulin concentrations in amniotic fluid be used as an indicator of fetal hyperinsulinemia in kindreds with prior newborn hyperinsulinemic hypoglycemia. This information may be used to direct timing of delivery and therapy in the immediate postnatal period.

Effect of intravenous beta-sympathomimetic tocolysis on human fetal serum erythropoietin levels

OBJECTIVE

The major stimulus for erythropoietin production is tissue hypoxia. We sought to investigate the relationship of beta-sympathomimetic administration for tocolysis and fetal serum erythropoietin.

STUDY DESIGN

Umbilical cord blood was obtained from infants whose mothers received intravenous beta-sympathomimetic tocolysis and who were delivered at < or = 34 weeks' gestation. Serum erythropoietin was measured by radioimmunoassay. On the basis of the presumed 2- to 4-hour half-life of fetal erythropoietin, the infants were divided into two groups. In group 1 (n = 16) beta-sympathomimetic therapy was discontinued < 24 hours before delivery; in group 2 (n = 11) it was discontinued > or = 24 hours before delivery.

RESULTS

Group 1 fetuses had significantly higher erythropoietin levels than did group 2 fetuses (37.3 vs 13.9 mU/ml, p = 0.02). The duration of beta-sympathomimetic tocolysis and the maximum infusion rate were not different. The two groups did not differ in gestational age, birth weight, route of delivery, presence of labor, or duration of first or second stage of labor.

CONCLUSIONS

We speculate that intravenous beta-sympathomimetic tocolytic therapy stimulates fetal erythropoietin production by decreasing fetal oxygenation as a result of the reversible fetal metabolic effects of the tocolysis. These data suggest that beta-sympathomimetic tocolysis should be undertaken cautiously if fetal compromise is suspected, fetal well-being should be assessed carefully if tocolysis is undertaken, and treatment should be discontinued promptly if a clear benefit is not realized.

Fetal plasma erythropoietin in pregnancies complicated by maternal diabetes mellitus

OBJECTIVE

Our purpose was to investigate the relationship between fetal plasma erythropoietin concentration and measures of short-term and long-term glycemic control and fetal oxygenation in pregnancies complicated by maternal diabetes mellitus.

STUDY DESIGN

A cross-sectional study was performed at The Harris Birthright Research Centre for Fetal Medicine, London. Cordocentesis was performed in 31 diabetic pregnancies for the measurement of umbilical venous blood pH, PO2, PCO2, lactate and glucose concentration, erythroblast count, hemoglobin, and plasma erythropoietin concentrations.

RESULTS

The mean pH was significantly lower and the PCO2, lactate, erythropoietin, hemoglobin, and erythroblast counts were significantly higher than the appropriate normal mean for gestation. There were significant associations between (1) fetal erythropoietin and erythroblast count, (2) fetal erythroblast count and hemoglobin, (3) fetal hemoglobin and maternal glycosylated hemoglobin, and (4) maternal glucose and fetal glucose, pH, and lactate.

CONCLUSIONS

We postulate that maternal hyperglycemia causes fetal hyperglycemia and acidemia. Increased erythropoietin may be caused by tissue hypoxia or hyperinsulinemia. The increase in fetal hemoglobin may be the consequence of increased erythropoiesis, mediated by either erythropoietin or hyperinsulinemia.

Neonatal hematocrit and maternal glycemic control in insulin-dependent diabetes

We hypothesized that in infants of diabetic women neonatal hematocrit would correlate with third-trimester maternal glycemic control. Neonatal hematocrit correlated with the maternal total glycosylated hemoglobin level at delivery (r = 0.36; p less than 0.05) but not at 36 weeks of gestation in 32 mother-infant pairs. Improved maternal glycemic control during late gestation may decrease the incidence of neonatal polycythemia.