[Continuous glucose monitoring using the glucose sensor CGMS in metabolically normal pregnant women during betamethasone therapy for fetal respiratory distress syndrome]

Alterations of materno-placento-fetal glucose homeostasis after a single course of antenatal betamethasone

INTRODUCTION

Intrauterine growth impairment is associated with long-term metabolic changes (perinatal programming). We recently demonstrated that antenatal betamethasone (BET) decreased head circumference in term born females. Since glucose is the main energy source for fetal growth, BET-induced changes in maternal glucose homeostasis, a reduced transplacental glucose transfer or an altered fetal glucose utilization may be linked with the observed growth impairment.

METHODS

86 pregnant women exposed to BET (single course, <34 + 0 weeks of gestation (wks)) were compared to 92 gestational-age/sex-matched controls. Glucose, insulin, leptin, insulin-like growth factors (IGF-1, IGF-2) and their binding proteins (IGFBP-1, IGFBP-3) were measured in maternal and umbilical cord blood samples. Homeostasis Model Assessment (HOMA-IR) was calculated. Placental glucose transporter 1 and 3 (GLUT1, GLUT3) protein levels were determined. Statistics were performed for overall and subgroup analysis (gestational age, sex).

RESULTS

After BET maternal HOMA-IR was elevated, IGFBP-1 reduced. In female pregnancies, glucose levels ≥37 + 0 wks and IGF-1 levels <37 + 0 wks were tendentially increased. Placental GLUT1 and GLUT3 protein levels were not significantly altered. Fetal umbilical venous glucose levels ≥37 + 0 wks were increased. HOMA-IR tended to be elevated in females.

DISCUSSION

Growth impairment after BET appears neither caused by maternal nor fetal hypoglycemia nor changes of GLUT1 and GLUT3 total protein levels. Nonetheless, glucose homeostasis of mothers and daughters was altered even beyond the BET time frame (hyperglycemia, enhanced insulin resistance). Despite glucose supply was sufficient, an anabolic effect was apparently absent. Overall, our results highlight the relevance of adequate glucose management after BET and peripartum.

Latency of late preterm steroid administration to delivery and risk of neonatal hypoglycemia

BACKGROUND

Late preterm antenatal corticosteroid administration has been associated with an increased risk of neonatal hypoglycemia. The mechanism is thought to be secondary to transient fetal hyperinsulinemia, which may be more likely if delivery occurs during peak antenatal corticosteroid levels.

OBJECTIVE

This study aimed to investigate whether there is a latency interval between antenatal corticosteroid administration and delivery that places neonates at the greatest risk of hypoglycemia.

STUDY DESIGN

This was a retrospective matched cohort study of pregnant women who received antenatal corticosteroid vs unexposed women between 34 0/7 and 36 6/7 weeks of gestation from 2016 to 2019. Unexposed women were those who did not receive antenatal corticosteroid matched according to gestational age at delivery, diabetes mellitus status, and maternal body mass index from 2010 to 2015. Latency periods from initial steroid administration to delivery were defined in grouped intervals until ≥72 hours. The primary outcome was neonatal hypoglycemia, defined as a neonatal glucose level of <40 mg/dL within 24 hours of life. Poisson regression was used to generate an adjusted relative risk of hypoglycemia for each latency period adjusting for confounders.

RESULTS

A total of 812 women were included in the analysis (406 exposed and 406 unexposed). Women who received antenatal corticosteroids were more likely to be nulliparous (P=.009); moreover, the women were well matched on pregnancy complications and baseline demographics. Neonatal hypoglycemia was more frequently identified in women receiving antenatal corticosteroids than in women not receiving antenatal corticosteroids (42% vs 26%; P<.001). Severe hypoglycemia, defined as a glucose level of <20 mg/dL, was significantly more common in patients receiving antenatal corticosteroids than in patients not receiving antenatal corticosteroids (8.4% vs 2.7%; P<.001). Latency time intervals of 12 to 71 hours from antenatal corticosteroid administration were significantly associated with neonatal hypoglycemia in exposed women compared with unexposed women after adjustment; within this time frame, the highest risk was 24 to 47 hours after antenatal corticosteroid administration (adjusted relative risk, 2.09; 95% confidence interval, 1.29-3.38).

CONCLUSION

In the late preterm period, the risk of neonatal hypoglycemia is the greatest in the latency period of 12 to 71 hours between steroid administration and delivery. Neonates exposed to antenatal corticosteroids were more likely to experience severe hypoglycemia within 24 hours of life than unexposed neonates.

Pharmacokinetics and Pharmacodynamics of Intramuscular and Oral Betamethasone and Dexamethasone in Reproductive Age Women in India

High-dose betamethasone and dexamethasone are standard of care treatments for women at risk of preterm delivery to improve neonatal respiratory and mortality outcomes. The dose in current use has never been evaluated to minimize exposures while assuring efficacy. We report the pharmacokinetics and pharmacodynamics (PDs) of oral and intramuscular treatments with single 6 mg doses of dexamethasone phosphate, betamethasone phosphate, or a 1:1 mixture of betamethasone phosphate and betamethasone acetate in reproductive age South Asian women. Intramuscular or oral betamethasone has a terminal half-life of 11 hours, about twice as long as the 5.5 hours for oral and intramuscular dexamethasone. The 1:1 mixture of betamethasone phosphate and betamethasone acetate shows an immediate release of betamethasone followed by a slow release where plasma betamethasone can be measured out to 14 days after the single dose administration, likely from a depo formed at the injection site by the acetate. PD responses were: increased glucose, suppressed cortisol, increased neutrophils, and suppressed basophils, CD3CD4 and CD3CD8 lymphocytes. PD responses were comparable for betamethasone and dexamethasone, but with longer times to return to baseline for betamethasone. The 1:1 mixture of betamethasone phosphate and betamethasone acetate caused much longer adrenal suppression because of the slow release. These results will guide the development of better treatment strategies to minimize fetal and maternal drug exposures for women at risk of preterm delivery.

Ritodrine Should Be Carefully Administered during Antenatal Glucocorticoid Therapy Even in Nondiabetic Pregnancies

Aim. Antenatal glucocorticoid therapy (AGT) has been commonly used recently. However, this therapy has severe harmful effects such as maternal hyperglycemia. In Japan, ritodrine hydrochloride has been used as a tocolytic agent. In this study, we performed retrospective casecontrol study to clarify whether concomitant use of ritodrine and glucocorticoid was safe to pregnant women without diabetes mellitus. Methods. We reviewed the computerized records of pregnant women with pregestational diabetes (n = 9) and nondiabetes (n = 45) who gave birth at our hospital between 2002 and 2011. Cases and controls received AGT. Blood glucose after the therapy was analyzed, and additional volume of insulin was compared to that before the therapy. Results. From this study, 30 units of insulin were necessary when performing AGT in diabetic pregnant women. And also, an increase in blood glucose of 40 mg/dL was seen after the therapy even in nondiabetic pregnant women. Blood glucose increased significantly in the group that also received ritodrine, and it was shown that the number of pregnant women who might develop ketoacidosis might increase 11-fold. Conclusions. Ritodrine should be carefully administered during antenatal glucocorticoid therapy. It may be necessary to adequately monitor blood glucose, when performing the therapy, even in nondiabetic pregnant women.

Effect of insulin and dexamethasone on fetal assimilation of maternal glucose

The growing fetus depends upon transfer of glucose from maternal blood to fetal tissues. Insulin and glucocorticoid impact maternal glucose metabolism, but the effects of these hormones on fetal glucose assimilation in vivo are understudied. We thus used positron emission tomography imaging to determine the disposition of [(18)F]fluorodeoxyglucose (FDG) in rats on gestational d 20, quantifying the kinetic competition of maternal tissues and fetus for glucose. Three fasting maternal states were studied: after 2-d dexamethasone (DEX), during euglycemic hyperinsulinemic clamp insulin receiving (INS), and control (CON). In CON and DEX mothers, FDG accumulation in fetuses and placentae was substantial, rivaling that of maternal brain. By contrast, FDG accumulation was reduced in INS fetuses, placentae, and maternal brain by approximately 2-fold, despite no diminution in FDG extraction kinetics from maternal blood into these structures. The reduced FDG accumulation was due to more rapid clearance of FDG from the circulation in INS mothers, related to increased FDG avidity in INS select maternal tissues, including skeletal muscle, brown adipose tissue, and heart. DEX treatment of mothers reduced fetal weight by nearly 10%. Nonetheless, the accumulation of FDG into placentae and fetuses was similar in DEX and CON mothers. In our rat model, fetal growth restriction induced by DEX does not involve diminished glucose transport to the fetus. Maternal insulin action has little effect on the inherent avidity of the fetal-placental unit for glucose but increases glucose utilization by maternal tissues, thus indirectly reducing the glucose available to the fetus.

[Obstetrical care in gestational diabetes and management of preterm labor]

OBJECTIVES

Search for data necessary to elaborate recommendations for obstetrical care in gestational diabetes and management of preterm labor.

METHODS

Systematic review of the literature and levels of evidence.

RESULTS

In case of gestational diabetes and in the absence of disease or other risk factor associated, there is no evidence to support a systematic rate of clinical follow up different from other pregnancy. The relevance of ultrasound estimates of fetal weight is limited. No formula is superior to others or to the simple measurement of abdominal circumference for the prediction of macrosomia (EL3). The usefulness of the research septal hypertrophy is not demonstrated (EL4). The systematic application of umbilical Doppler has no proven benefits in the absence of growth restriction or hypertension associated (EL4). Monthly ultrasound monitoring of the fetus can be proposed for diabetics on insulin or poorly controlled. In cases of gestational diabetes controlled by diet, cardiotocography of fetal heart rate has not proven useful. In poorly controlled diabetes and/or on insulin, the registration may be discussed taking into account other risk factors associated (EL4). A weekly recording of fetal heart rate is often recommended in case of type 2 diabetes discovered during pregnancy. In case of preterm labor, calcium channel blockers and oxytocin antagonists can be used without specific precautions. The risk of using beta-adrenergic outweighs the benefit. Administration of corticosteroid can be done under glycemic control, with insulin therapy if necessary. Screening test for gestational diabetes should not be performed within few days after last steroid injection.

Use of real time continuous glucose monitoring and intravenous insulin in type 1 diabetic mothers to prevent respiratory distress and hypoglycaemia in infants

Background

Pregnancy in Type 1 diabetic patients is a precarious condition, both for mother and fetus with increased the risk of prematurity and, immediately after delivery with risk of respiratory distress syndrome and hypoglycaemia in newborns. A strict control and monitoring of diabetes throughout pregnancy is important in reducing the impact of the disease on the fetus and newborn. In recent years many new technologies have been introduced to ameliorate diabetes monitoring, where the last is the Real-time Continuous Glucose Monitoring System (RT-CGMS).

Methods

In the last three years, 72 h continuous glucose monitoring system (RT-CGMS) (Medtronic, CA) was performed in 18 pregnant women with Type 1 diabetes in two moments of pregnancy: during treatment with betamethasone to prevent respiratory distress and during delivery. In both cases insulin was administered intravenous and the dose was changed on the basis of glycaemia.

Results

The results present the use of this new technique during two topics moments of pregnancy of type 1 diabetes patients when is very important intensively to monitor diabetes and to obtain the well being of the fetus. No infant experimented hypoglycaemia or respiratory distress syndrome at the moment and in the first hours after the birth.

Conclusion

We wish to stress the importance reducing glycaemia during administration of betamethasone and during labor. It is conceivable that the scarce attention paid to monitoring glucose levels in diabetic mothers during labor in gynaecological world may be due to the difficulty in glucose monitoring with the devices until now available. Hopefully, our anecdotal account may prompt improvements with RT-CGMS, and may lead to a better approach to the problem, thereby changing the prognosis of infants born to diabetic mothers.

Longitudinal changes in the continuous glucose profile measured by the CGMS in healthy pregnant women and determination of cut-off values

OBJECTIVE

This longitudinal study performed continuous evaluation of daily blood glucose level profiles in healthy normal-weight pregnant patients during various gestational age and determined normal levels.

STUDY DESIGN

Thirty-two healthy normal-weight pregnant women received a continuous glucose monitoring system (CGMS) device for periods of 72h in the 16th, 22nd, 30th and 36th weeks of gestational age and at 6 weeks after delivery. All observations took place in the outpatient clinic of the Charité hospital. The daily blood glucose level profiles obtained with the CGMS provided pre- and postprandial blood glucose levels and a mean glucose value for a 24-h period. Caloric intake was determined using detailed food logs. Additionally, a fetal biometry and an measurement of maternal weight were performed at each visit. The correlation was tested using Spearman's test.

RESULTS

The average age of the study subjects was 29.6+/-4.5. Average pre-pregnancy BMI was 22.4+/-2.5kg/m(2). The births occurred on average in the 40th week of pregnancy. Average caloric intake was 2223+/-356kcal. No significant changes in caloric intake were observed during the course of the study. The blood glucose levels showed a significant rise throughout the course of the pregnancy, going from 4.84+/-0.4mmol/l (87.2+/-7.2mg/dl) during the 30th week of pregnancy to 5.22+/-0.5mmol/l (94.0+/-9.0mg/dl) during the 36th week (p=0.002). Postpartum levels were 5.20+/-0.5mmol/l (93.7+/-9.0mg/dl) (p=0.51). Fasting blood glucose levels did not change during the course of the pregnancy. A noticeable aspect were the significantly increased fasting postpartum levels with 5.02+/-0.6mmol/l (90.4+/-10.8mg/dl) (p=0.00). Analysis of the postprandial glucose levels confirmed a rise from 5.30+/-0.6mmol/l (95.5+/-10.8mg/dl) in the 16th week to 6.14+/-0.7mmol/l (110.6+/-12.6mg/dl) in the fourth study phase (36th week), and a decrease after the birth to 5.59+/-0.6mmol/l (100.7+/-10.8mg/dl). These measurements were adapted to the gestational age.

CONCLUSION

Continuous measured glucose levels rose during the pregnancy in healthy pregnant women in spite of normal pre-pregnancy metabolism and unchanged carbohydrate intake during gestation. These results suggest the necessity of gestational-age-dependent cut-off values.