Effect of maternal hyperketonemia in hyperglycemic pregnant ewes and their fetuses

Diabetic ketoacidosis in pregnancy - Case series, pathophysiology, and review of the literature

OBJECTIVE

Diabetic ketoacidosis (DKA) during pregnancy is a life-threatening emergency for both the mother and the fetus. The pathophysiology of DKA in pregnancy has its own characteristics due to multiple factors, such as insulin resistance, accelerated starvation and respiratory alkalosis, thus creating ketosis-prone state, with DKA occurring at milder degrees of hyperglycemia, even in normoglycemic levels, which can result in delayed diagnosis and treatment with potential for adverse metabolic consequences.

STUDY DESIGN

In this article, we presented 8 clinical cases of DKA during pregnancy. We discuss the spectrum of the clinical picture, the entity of euglycemic DKA vs hyperglycemic DKA, the period of pregnancy in appearance of episode of DKA and triggers of DKA.

CONCLUSION

The treatment of DKA in pregnant women must be started immediately and must be accentuated on intravenous fluids, insulin and electrolyte replacement. DKA in pregnancy may be euglycemic. Prevention, early recognition, immediate hospitalization, and aggressive management remain the cornerstones in DKA management in pregnancy.

Maternal Obesity and Diabetes Mellitus as Risk Factors for Congenital Heart Disease in the Offspring

Congenital heart disease (CHD) is the most common anatomical malformation occurring live‐born infants and an increasing cause of morbidity and mortality across the lifespan and throughout the world. Population‐based observations have long described associations between maternal cardiometabolic disorders and the risk of CHD in the offspring. Here we review the epidemiological evidence and clinical observations relating maternal obesity and diabetes mellitus to the risk of CHD offspring with particular attention to mechanistic models of maternal‐fetal risk transmission and first trimester disturbances of fetal cardiac development. A deeper understanding of maternal risk factors holds the potential to improve both prenatal detection of CHD by identifying at‐risk pregnancies, along with primary prevention of disease by improving preconception and prenatal treatment of at‐risk mothers.

Polycythaemia in infants of diabetic mothers: β-hydroxybutyrate stimulates erythropoietic activity

This study tested whether elevated maternal β-hydroxybutyrate (β-OHB) levels contribute to polycythaemia in infants of diabetic mothers. Pregnant diabetic women (n = 27) and non-diabetic controls (n = 20) and their singleton infants were included. Maternal glycosylated haemoglobin and β-OHB levels were studied at 34-36 weeks' gestation; levels were significantly higher in mothers with diabetes than in controls. Birth weights and cord blood levels of insulin and fetal haemoglobin were significantly higher in infants from diabetic mothers compared with control infants, as were haematocrit levels in venous blood samples taken from each infant at 4 h following delivery. Cord blood erythropoietin levels were similar in both groups. There was a positive strong correlation between maternal β-OHB levels and polycythaemia in newborn infants, indicating that β-OHB could activate erythropoiesis independently from intrauterine hyperinsulinaemia and/or erythropoietin levels, and may be important in the pathogenesis of polycythaemia in infants born to diabetic mothers.

Bilateral basal ganglia infarctions in a neonate born during maternal diabetic ketoacidosis

Diabetic ketoacidosis (DKA) during pregnancy carries significant risk of intrauterine fetal demise, but little is known about its postnatal sequelae in surviving neonates. We report here the case of an infant who was born to a mother with White's class C diabetes mellitus during an episode of DKA. Throughout pregnancy her glucose control was suboptimal, as evidenced by a predelivery glycosylated hemoglobin level of 8.1%. At 33 weeks' gestation, the mother presented with nausea and vomiting, a serum glucose concentration of 575 mg/dL, and other metabolic derangements consistent with DKA. Despite rehydration and insulin therapy, fetal distress necessitated cesarean delivery. At birth the infant required intubation, but her clinical status quickly improved and she was extubated within the first day of life. However, on day-of-life 4 she exhibited seizure-like activity, and subsequent brain MRI revealed bilateral basal ganglia infarctions. Previous research has revealed that the keto acid β-hydroxybutyrate (β-OHB) can cross the placenta into the fetal circulation and thereafter accumulate in the fetal brain, which leads to severe metabolic derangements. Furthermore, β-OHB accumulates rapidly in the basal ganglia of older children during episodes of DKA, wherein its presence is associated with neuronal injury. We suspect that transplacental transfer of maternal β-OHB led to an acquired ketoacidosis in the fetus and that accumulation of β-OHB contributed to neuronal injury and subsequent infarction of the basal ganglia. Further research is necessary to better characterize neonatal complications of maternal DKA, as well as the possible inclusion of β-OHB levels in the goal-directed treatment of this disease.

Fetal monitoring in type 1 diabetic pregnancies

Stillbirth and perinatal mortality rates are 5 times greater for an insulin-dependant diabetic mother than in the general population. Neonatal and infant mortality rates are 15 and 3 times greater, respectively. In addition, macrosomia is a major problem resulting in both fetal and maternal injury. Fetal monitoring is considered mandatory in such pregnancies. The rational approach would be to use surveillance strategies based on the underlying pathophysiology. However, in the diabetic pregnancy, the underlying pathophysiology is poorly understood and is likely to be multifactorial. Thus, in practice, a pragmatic approach is followed using methods that are applied in other high-risk pregnancies although the pathophysiology is different. Given the limitations in the predictive power of many fetal monitoring methods and the lack of randomised controlled trials, it is not surprising that there is no agreement over the best way to monitor fetal health in diabetic pregnancies. This article analyses the evidence regarding the value of these tests and proposed protocols for their use in the context of the diabetic pregnancy.

Diabetic ketoacidosis in pregnancy

Diabetic ketoacidosis (DKA) remains a medical emergency with high maternal and fetal mortality. Prompt recognition and resuscitative therapy markedly improves outcome. The pathophysiology and management of DKA in pregnancy is discussed in detail in this article.

Common clinical manifestations of maternal diabetes in newborn infants: implications for the practicing pediatrician

Even though perinatal mortality of infants of diabetic mothers has decreased remarkably in recent years and now approaches that of the general population, these infants still face a multitude of potential complications and the propensity for increased morbidity, both in utero and postnatally. Many of these complications are clearly related to the metabolic status of the diabetic mother. Increasing awareness among insulin-dependent diabetic patients and health providers of the need for glycemic control and the ever-growing understanding of the peculiarities of diabetic pregnancies eventually should combine to provide the best possible outcome for these infants.

Management of hypoglycemia and diabetic ketoacidosis in pregnancy

The article discusses the incidence and management of hypoglycemia and diabetic ketoacidosis (DKA) in pregnancy. Additional topics addressed are the incidence of hypoglycemia, pathophysiology, diagnosis and management of hypoglycemia in pregnancy, fetal monitoring with short- and long-term fetal sequelae, and prevention of hypoglycemic recurrences. Subsequently, attention is focused on the diagnosis and management of hyperglycemia and DKA in pregnancy.

Poor glycemic control and antepartum obstetric complications in women with insulin-dependent diabetes

OBJECTIVE

The purpose of this study was to test the hypothesis that the rate of complications of pregnancy in women with insulin-dependent diabetes is higher than in nondiabetic women and is associated with poor glycemic control and microvascular disease.

METHOD

Women who enrolled in a multidisciplinary program of diabetes in pregnancy prior to 20 weeks' gestation were included in the study and matched 1:2 by age, race and parity to a control group of nondiabetic women. Complications of pregnancy were retrospectively analyzed and compared between groups. The association of complications with glycemic control and microvascular disease was analyzed within the diabetic group.

RESULT

Women with diabetes had significantly higher rates of pregnancy-induced hypertension (PIH), polyhydramnios, pyelonephritis, preterm delivery and meconium-stained amniotic fluid. Poor glycemic control, particularly during the first and second trimesters of pregnancy, was associated with all complications, except pyelonephritis. Microvascular disease was associated with PIH and preterm delivery prior to 34 weeks.

CONCLUSION

Women with insulin-dependent diabetes are at high risk for complications of pregnancy. Glycemic control during the first and second trimesters may affect events later in pregnancy.

Effects of beta-hydroxybutyrate infusion on hind limb metabolism in fetal sheep

OBJECTIVES

This study investigated the effects of high ketone levels on fetal carcass metabolism. Specifically, we aimed to determine whether beta-hydroxybutyrate was taken up by fetal muscle and whether lactate production by the fetal hind limb contributed to the raised circulating lactate levels seen in high ketone states.

STUDY DESIGN

Hind limb metabolism was studied in 10 chronically catheterized fetal sheep. Substrate/oxygen quotients were measured before and after 2 hour infusions of beta-hydroxybutyrate and compared with the Wilcoxon signed-rank test.

RESULTS

beta-Hydroxybutyrate was taken up by hind limb tissues in large amounts (butyrate/oxygen quotient = 1.02 +/- 0.40). Lactate was produced by the hind limb (lactate/oxygen quotient = -0.96 +/- 0.52) in amounts almost equivalent to glucose uptake (glucose/oxygen quotient = 1.32 +/- 0.29). Hind limb oxygen consumption increased 35% and fetal arterial oxygen content fell 16%.

CONCLUSION

beta-Hydroxybutyrate may be consumed by the fetal carcass in amounts sufficient to entirely substitute for glucose. Glucose may then be released as lactate for metabolism elsewhere. Ketones may be important fetal substrates during maternal starvation.

Maternal glucose loading and fetal cardiac function in humans

Fetal cardiac function determined using M-mode echocardiography was studied subsequent to the maternal intravenous injection of 20 g of glucose. There were 11 appropriate for date infants (AFD), 7 noneventful, light for date infants (LFD) and one high risk fetus in severe toxemia of pregnancy (Case 1), at 32-40 weeks' gestation. The fetal heart rate showed no significant changes after glucose injection in each group. The left ventricular fractional shortening and cardiac output showed significant changes, whereas the right ventricular fractional shortening and cardiac output were unchanged in both AFD and LFD. In Case 1, the adverse change was noted in both left and right cardiac functions, as compared with AFD or LFD. The combined total cardiac output in AFD increased significantly at 5 min following glucose injection, whereas that in LFD did not change significantly. On the other hand, the combined total cardiac output in Case 1 decreased markedly at 5 min after glucose injection. These findings show that the glucose loading in the mother alters cardiac function in the fetus.

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

In the present study the antepartum relationship between maternal diabetic glucose control and fetal hypoxaemia was examined in 44 Type 1 (insulin-dependent) diabetic and 23 non-diabetic control pregnancies. Maternal HbA1C was used to assess maternal integrated blood glucose control while fetal metabolic control was evaluated by antepartum glucose, insulin, and C-peptide determinations in amniotic fluid at elective caesarean delivery. Fetal hypoxaemia was assessed indirectly by fetal umbilical vein plasma erythropoietin level at delivery. A prospectively developed statistical pathway model was used to examine the relationship of these variables. In applying forced stepwise multiple regression with this model, we observed in the diabetic subjects that mean maternal HbA1C during the last month of pregnancy correlated significantly with fetal umbilical venous erythropoietin at delivery (r = 0.57, p less than 0.001). Additional significant contributions to umbilical venous erythropoietin were found for amniotic fluid glucose and amniotic fluid insulin when these two independent variables were added in stepwise fashion (p less than 0.01). We conclude that in diabetic pregnancy, antepartum control of maternal hyperglycaemia is a significant factor associated with fetal hypoxaemia. We speculate that this effect is mediated through perturbations which accelerate fetal metabolism and which is expressed by amniotic fluid levels of glucose and insulin.

Alloxan-induced diabetes mellitus in the pregnant ewe: metabolic and cardiovascular effects on the mother and her fetus

Diabetes mellitus was acutely produced in nine pregnant sheep by the intravenous administration of alloxan 40 mg/kg in the maternal inferior vena cava. Maternal and fetal plasma concentrations of glucose, lactate, beta-hydroxybutyrate, insulin, glucagon, and PaO2, oxygen content, and pH were determined before and at days 1, 3, and 5 after the injection of alloxan. Two animals aborted between days 1 and 3 after alloxan administration. In the other animals, significant changes occurred from baseline to day 5: maternal hyperglycemia (56.8 +/- 5.2 vs. 227.3 +/- 54.6 mg/dl; p less than 0.01), maternal hypoinsulinemia (6.2 +/- 3.5 vs. 1.0 +/- 0.4 microU/ml, p = 0.016); maternal hyperketonemia (beta-hydroxybutyrate: 0.79 +/- 0.27 vs. 4.69 +/- 2.64 mmol/L, p less than 0.01); fetal hyperglycemia (17.0 +/- 2.6 vs. 86.0 +/- 16.2 mg/dl, p less than 0.001); fetal hyperinsulinemia (8.4 +/- 4.5 vs. 19.2 +/- 6.4 microU/ml, p less than 0.001); fetal hyperketonemia (beta-hydroxybutyrate: 0.03 +/- 0.03 vs. 0.06 +/- 0.02 mmol/L, p less than 0.05); fetal hypoxemia (arterial PO2: 21.6 +/- 1.8 vs. 18.0 +/- 2.8 mm Hg, p less than 0.05, and oxygen content: 7.1 +/- 0.5 vs. 4.5 +/- 1.9 vol/dl, p less than 0.02). Thus alloxan administered in the pregnant ewe can produce major metabolic and endocrine derangements acutely simulating those occurring in human insulin-dependent diabetic pregnancy.

Perinatal asphyxia in infants of insulin-dependent diabetic mothers

Infants of diabetic mothers are thought to be at risk for perinatal asphyxia. We hypothesized that the following are significant risk factors for perinatal asphyxia: poor third-trimester glycemic control, diabetic vascular disease (nephropathy, retinopathy) appearing in pregnancy, pregnancy-associated hypertension, smoking, prematurity, fetal macrosomia, and maternal hyperglycemia and hypoglycemia within 6 hours preceding delivery. We prospectively studied 162 infants born to 149 diabetic mothers (White classes B through R-T). Perinatal asphyxia was defined clinically as fetal distress during labor (late decelerations, persistent fetal bradycardia, or both), 1-minute Apgar score less than or equal to 6, or intrauterine fetal death. Forty-four infants (26.7%) had perinatal asphyxia. The presence of perinatal asphyxia did not correlate with third-trimester glycemic control, pregnancy-associated hypertension, smoking, fetal macrosomia, or maternal hypoglycemia before delivery, but it did correlate significantly with nephropathy appearing in pregnancy, maternal hyperglycemia before delivery, and prematurity. We speculate that (1) the appearance of diabetic vasculopathy (nephropathy) during pregnancy is accompanied by placental vascular disease and subsequently by fetal compromise and (2) in pregnancy complicated by diabetes, maternal and subsequently fetal hyperglycemia before delivery leads to fetal hypoxemia.