Control of blood glucose during labour in diabetic women with combined glucose and low-dose insulin infusion

Type 2 diabetes and neonatal hypoglycemia: role of route of delivery and insulin infusion

OBJECTIVE

To compare the rate of neonatal hypoglycemia among newborns delivered by individuals with Type 2 diabetes mellitus (T2DM) in two clinical scenarios: who attempted vaginal delivery vs. had a planned cesarean delivery (CD); who had intrapartum insulin infusion vs. who did not.

METHODS

This was a retrospective cohort study of individuals with insulin-treated T2DM who had non-anomalous singleton pregnancy and delivered at a single tertiary center (March 2012 and May 2018). Individuals with chronic renal failure, proliferative retinopathy, or major congenital anomalies were excluded. The primary outcome was neonatal hypoglycemia (blood glucose < 40 mg/dl <24 h of age or < 50 mg/dl >24 h of age). Secondary outcomes included neonatal outcomes. Multivariable Poisson regression models with robust error variance were used to examine the association between groups and the primary outcome. Adjusted relative risk (aRR) and 95% confidence intervals (CI) were calculated.

RESULTS

Of 233 individuals with T2DM, 215 (92.2%) met the inclusion criteria, of whom 95 (44%) attempted vaginal delivery and 120 (56%) had a planned CD. Individuals who labored had a higher gestational age at delivery (36.6 vs. 35.8 weeks, p = .005), and higher blood glucose levels upon admission (125 vs 103, p < .001) compared to those with a planned CD. After adjustment for potential confounders, there was no difference in risk of neonatal hypoglycemia between the groups (41.2 vs 44.1%, aRR 1.05, 95% CI = 0.75-1.45). Among those who attempted vaginal delivery, 34 (35.8%) required insulin infusion. There was no difference in the risk of neonatal hypoglycemia (aRR = 0.79, 95% CI = 0.45-1.37) between newborns delivered by individuals who required insulin infusion and those who did not.

CONCLUSION

Over 40% of newborns delivered by individuals with insulin-dependent T2DM had hypoglycemia; however, there was no significant difference in the risk of hypoglycemia, irrespective of the route of delivery and the use of insulin infusion.

Peripartum management of glycemia in women with type 1 diabetes

OBJECTIVE

We aimed to 1) describe the peripartum management of type 1 diabetes at an Australian teaching hospital and 2) discuss factors influencing the apparent transient insulin independence postpartum.

RESEARCH DESIGN AND METHODS

We conducted a retrospective review of women with type 1 diabetes delivering singleton pregnancies from 2005 to 2010. Information was collected regarding demographics, medical history, peripartum management and outcome, and breast-feeding. To detect a difference in time to first postpartum blood glucose level (BGL) >8 mmol/L between women with an early (<4 h) and late (>12 h) requirement for insulin postpartum, with a power of 80% and a type 1 error of 0.05, at least 24 patients were required.

RESULTS

An intravenous insulin infusion was commenced in almost 95% of women. Univariate analysis showed that increased BMI at term, lower creatinine at term, longer duration from last dose of long- or intermediate-acting insulin, and discontinuation of an insulin infusion postpartum were associated with a shorter time to first requirement of insulin postpartum (P = 0.005, 0.026, 0.026, and <0.001, respectively). There was a correlation between higher doses of insulin commenced postpartum and number of out-of-range BGLs (r[36] = 0.358, P = 0.030) and hypoglycemia (r[36] = 0.434, P = 0.007). Almost 60% had at least one BGL <3.5 mmol/L between delivery and discharge.

CONCLUSIONS

Changes in the pharmacodynamic profile of insulin may contribute to the transient insulin independence sometimes observed postpartum in type 1 diabetes. A dose of 50-60% of the prepregnancy insulin requirement resulted in the lowest rate of hypoglycemia and glucose excursions. These results require validation in a larger, prospective study.

Inpatient management of women with gestational and pregestational diabetes in pregnancy

For women with type 1 diabetes (T1DM), type 2 diabetes (T2DM), and gestational diabetes (GDM), poor maternal glycemic control can significantly increase maternal and fetal risk for adverse outcomes. Outpatient medical and nutrition therapy is recommended for all women with diabetes in order to facilitate euglycemia during the antepartum period. Despite intensive outpatient therapy, women with diabetes often require inpatient diabetes management prior to delivery as maternal hyperglycemia can significantly increase neonatal risk of hypoglycemia. Consensus guidelines recommend maternal glucose range of 80-110 mg/dL in labor. The most optimal inpatient strategies for the prevention of hyperglycemia and hypoglycemia proximate to delivery remain unclear and will depend upon factors such as maternal diabetes diagnosis, her baseline insulin resistance, duration and route of delivery etc. Low dose intravenous insulin and dextrose protocols are necessary to achieve optimal predelivery glycemic control for women with T1DM and T2DM. For most with GDM however, euglycemia can be maintained without intravenous insulin. Women treated with a subcutaneous insulin pump during the antepartum period represent a unique challenge to labor and delivery staff. Strategies for self-managed subcutaneous insulin infusion (CSII) use prior to delivery require intensive education and coordination of care with the labor team in order to maintain patient safety. Hospitalization is recommended for most women with diabetes prior to delivery and in the postpartum period despite appropriate outpatient glycemic control. Women with poorly controlled diabetes in any trimester have an increased baseline maternal and fetal risk for adverse outcomes. Common indications for antepartum hospitalization of these women include failed outpatient therapy and/or diabetic ketoacidosis (DKA). Inpatient management of DKA is a significant cause of maternal and fetal morbidity and remains a common indication for hospitalization of the pregnant woman with diabetes. Changes in maternal physiology increase insulin resistance and the risk for DKA. A systematic approach to its management will be reviewed.

Glucose control during labor and delivery

Neonatal hypoglycemia is an important consequence for the infant of the mother with diabetes. We have reviewed 24 published papers of various protocols for control of glucose in pregnant diabetic women during labor and delivery including our own published work. A relationship of maternal glucose during labor and neonatal hypoglycemia was sought in 19 of these studies. A significant inverse relationship was found in 10 reports with 3 others showing a similar trend. In all but 1 of these 13 studies the participants had pregestational diabetes. Three of the 6 studies not reporting an inverse relationship involved women with GDM. From this review it appears that the maternal glucose should be maintained between 4.0 and 6.0-7.0 mmol/L during labor. Most women with gestational diabetes, especially if they require <1.0 units/kg/d of insulin, can simply be monitored without intravenous insulin. Our own results demonstrate that a target glucose of 4.0-6.0 mmol/L can be used safely and results in a low rate of neonatal hypoglycemia using an iterative glucose insulin infusion protocol for women with pregestational diabetes and when needed for women with gestational diabetes.

[Gestational diabetes mellitus: importance of blood glucose monitoring]

Gestational diabetes mellitus (GDM) is common during pregnancy, and is frequently associated with maternal and perinatal complications. Intensive treatment of hyperglycaemia during pregnancy has been shown to reduce perinatal morbidity. In women with pregestational type 1 or 2 diabetes, hyperglycaemia during labour and delivery is an important factor in the development of neonatal hypoglycaemia. There are no generally accepted recommendations for women with GDM. Recent studies evaluating patients with GDM show that peripartum glucose control can be achieved in these women without the need for insulin use in the majority of cases. Hyperglycaemia during labour is not related with treatment established during pregnancy but rather with non-compliance of endocrinological follow-up. Factors such as ethnic origin, neonatal hypoxaemia, and large for gestational age seem to play an important role in the development of neonatal hypoglycaemia.

Intrapartum application of the continuous glucose monitoring system in pregnancies complicated with diabetes: A review and feasibility study

Intrapartum maternal normoglycemia seems to play an important role in the prevention of adverse perinatal, maternal and neonatal outcomes. Several glucose monitoring protocols have been developed, aiming to achieve a tight glucose monitoring and control. Depending on the type of diabetes and the optimal or suboptimal glycemic control, the treatment options include fasting status of the parturient, frequent monitoring of capillary blood glucose, intravenous dextrose infusion and subcutaneous or intravenous use of insulin. Continuous glucose monitoring system (CGMS) is a relatively new technology that measures interstitial glucose at very short time intervals over a specific period of time. The resulting profile provides a more comprehensive measure of glycemic excursions than intermittent home blood glucose monitoring. Results of studies applying the CGMS technology in patients with or without diabetes mellitus (DM) have revealed new insights in glucose metabolism. Moreover, CGMS have a potential role in the improvement of glycemic control during pregnancy and labor, which may lead to a decrease in perinatal morbidity and mortality. In conclusion, the use of CGMS, with its important technical advantages compared to the conventional way of monitoring, may lead into a more etiological intrapartum management of both the mother and her fetus/infant in pregnancies complicated with DM.

Peripartum metabolic control in gestational diabetes

OBJECTIVE

We sought to evaluate intrapartum metabolic control in gestational diabetes mellitus (GDM) patients and maternal factors influencing intrapartum glycemic control and neonatal hypoglycemia risk.

STUDY DESIGN

A prospective observational study included 129 women with GDM admitted for delivery. Data collected included maternal intrapartum capillary blood glucose (CBG) and ketonemia, use of insulin, and neonatal hypoglycemia.

RESULTS

In all, 86% of maternal intrapartum CBG values fell within target range (3.3-7.2 mmol/L) without need for insulin use. There were no cases of maternal hypoglycemia or severe ketosis. Intrapartum CBG >7.2 mmol/L was associated with third-trimester glycated hemoglobin (P = .02) and lack of endocrinologic follow-up (P = .04). Risk of neonatal hypoglycemia was related with pregnancy insulin use compared with dietary control (60.5% vs 29.5%; P = .02).

CONCLUSION

Peripartum metabolic control in GDM patients was achieved without insulin in most cases. Intrapartum glycemic control was related with third-trimester glycated hemoglobin and with no endocrinologic follow-up. Neonatal hypoglycemia was associated with insulin use during pregnancy.

Antepartum and intra-partum insulin management of type 1 and type 2 diabetic women: Impact on clinically significant neonatal hypoglycemia

OBJECTIVE

Assess efficacy of intrapartum intravenous (i.v.) insulin and effect of antepartum and intrapartum diabetic control on various measures of clinical neonatal hypoglycemia.

DESIGN

Retrospective chart review.

SETTING

Regional Diabetes in Pregnancy Clinic.

RESULTS

Maternal hypoglycemia occurred intrapartum in 56% of subjects. Mean delivery blood glucose with intravenous insulin use was 6.7mmol/l. Capillary blood glucose <2.2mmol/l occurred in 69% of neonates and 44% received intravenous glucose. Maternal delivery glucose >6.5mmol/l correlated with occurrence of neonatal glucose <2.2mmol/l but not requirement for i.v. glucose or NICU admission. A third trimester HbA1c >6.5% had a stronger association with NICU admission and i.v. glucose requirement.

CONCLUSIONS

Blood glucose at delivery >6.5mmol/l predicts neonatal hypoglycemia but does not correlate with severity. Chronic maternal hyperglycemia, reflected by pre-delivery HbA1c, predicts severe fetal hyperinsulinism and requirement for aggressive intervention. This stresses the importance of a target third trimester HbA1c of <6.5%.

Intrapartum maternal glycemic control in women with insulin requiring diabetes: a randomized clinical trial of rotating fluids versus insulin drip

OBJECTIVE

The purpose of this study was to determine whether continuous insulin infusion provides a greater degree of intrapartum maternal glycemic control than rotating between glucose and non-glucose containing intravenous fluids.

STUDY DESIGN

Laboring patients with pregestational or gestational diabetes were recruited and randomized to an "insulin drip" or "rotating fluids" protocol. The primary outcome measure was mean maternal capillary blood glucose (CBG) levels (mg/dL). Power analysis indicated that 16 patients were needed in each arm to find a difference of 10 mg/dL.

RESULTS

Fifteen patients were randomized to the rotating fluids protocol and 21 patients to an insulin drip. There was no difference in mean intrapartum maternal CBG levels (103.9 +/- 8.7 mg/dL and 103.2 +/- 17.9 mg/dL in the rotating fluids and insulin drip group, respectively, P = .89). Neonatal outcomes were also similar between the 2 treatment groups.

CONCLUSION

In patients with insulin requiring gestational diabetes, intrapartum glycemic control may be comparable with a standard adjusted insulin drip or a rotation of intravenous fluids between glucose and non-glucose containing fluids.

Glucose and insulin requirements during labor and delivery: the case for normoglycemia in pregnancies complicated by diabetes

OBJECTIVE

To present protocols for maintaining normoglycemia during labor and delivery in order to achieve optimal outcomes of pregnancy in women with diabetes.

RESULTS

Labor has a glucose-lowering effect. In the case of women with insulin-requiring gestational diabetes, no additional insulin is needed with the onset of labor; sufficient glucose should be infused to keep such women from becoming ketotic from the pronged period of starvation. Likewise, protocols derived from glucose-controlled insulin infusion studies reveal that women with type 1 diabetes require no more subcutaneously administered insulin on the morning of an induction of labor or at the onset of spontaneous labor. The intravenously administered solutions should be started with isotonic saline or electrolyte solutions. As soon as active labor is achieved, the solutions should be switched to a glucose-containing fluid and administered at a rate of 2.55 mg/kg per minute.

CONCLUSION

Labor is a form of exercise and thus obviates the insulin requirement in women with all types of diabetes, but it also necessitates an eightfold increase in glucose substrate in order to prevent maternal hypoglycemia and ketosis. The literature presents clear evidence that neonatal hypoglycemia is directly related to maternal hyperglycemia during labor and delivery. Thus, protocols for maintaining normoglycemia during labor and delivery are necessary to achieve optimal results.

Cord blood insulin to assess the quality of treatment in diabetic pregnancies

According to the Pedersen hypothesis, fetal hyperinsulinism is the major cause for adverse neonatal outcome. We investigated associations between insulin levels in cord blood and fetal complications. Three groups of 21 insulin-dependent diabetic patients with different insulin levels in cord blood were matched according to White Classes. Insulin levels in cord blood of < 20 microU/ml were considered normal (controls), 20-50 microU/ml intermediate group, and > 50 microU/ml high (cases). The mean (+/-S.D.) insulin level in cord blood in the three groups was 10.7+/-5.6, 28.6+/-8.1, and 104.0+/-61.0 microU/ml, respectively. Controls and cases showed significant differences in birth weight > 90th percentile (9.5% vs. 76.2%), premature birth < 37 weeks (4.8% vs. 71.4%), caesarean delivery (28.6% vs. 66.4%), hypoglycaemia of the neonate (14.3% vs. 61.9%), cushingoid appearance (4.8% vs. 42.9%) and respiratory distress syndrome (0% vs. 33.3%). The results of the intermediate group were between the controls and the cases. Insulin levels in cord blood > 20 microU/ml represent a continuum of increasing diabetogenic fetopathy. We consider neonates with insulin levels in cord blood < 20 microU/ml as metabolically healthy, those with 20-50 microU/ml as having mild fetopathy, and those with > 50 microU/ml as having marked fetopathy, respectively.

Difference in prevalence of gestational diabetes and perinatal outcome in an innercity multiethnic London population

In order to establish the prevalence of gestational diabetes mellitus (GDM) among ethnic groups residing in the catchment area of one hospital in central London and to assess both the mode of delivery and the baby outcome, we studied retrospectively 703 women selected for screening for GDM during the years 1991 and 1992. While the prevalence of GDM was approximately 2% overall, within the ethnic groups a significant difference was found with Asians and Africans/Afrocaribbeans being four and two times more likely to have GDM, respectively, than Caucasians (P < 0.001). Both maternal obesity and the diagnosis of GDM influenced the time and the mode of delivery, but perinatal mortality and morbidity did not differ significantly between women with GDM and women with normal glucose tolerance. An association between the GTT glucose area and the gestational age and ethnicity adjusted birth weight was observed in women with normal glucose tolerance test, but was absent in the GDM pregnancies, providing indirect evidence that dietary treatment, with or without insulin treatment, altered the maternal milieu in the latter sufficiently to modify fetal growth.

Gestational diabetes. What are the implications?

Although gestational diabetes may have serious consequences for both mother and fetus, it is usually symptomless. The diagnosis can be missed unless all pregnant women are screened to determine those who need a full oral glucose tolerance test. When gestational diabetes is diagnosed, it is essential to (1) achieve euglycemia with diet and, if needed, insulin and (2) monitor for potential complications. Glucose tolerance must be reevaluated in the post-partum period and periodically thereafter to detect continuing intolerance or diabetes.

Diabetes and pregnancy

Despite improvement in perinatal outcome over the past several decades, controversy still exists regarding both the management and pathophysiology of pregnancy complicated by diabetes mellitus. In this article, potential factors contributing to morbidity observed in the offspring of diabetic women are considered. The clinical management of insulin-dependent and gestational diabetes is also discussed.

Seven years experience of home management in pregnancy in women with insulin-dependent diabetes

Fifty-eight of a consecutive series of 75 pregnancies in women with insulin-dependent diabetes went into the third trimester. Diabetes was managed by home blood glucose monitoring and women were not routinely admitted at any stage before delivery. The mean number of in-patient days before delivery was 15 for the whole series but has been reduced to 9 during the past four years. Each woman performed an average of 171 blood glucose measurements during her pregnancy. Mean blood glucose (including post-prandial levels) fell significantly from 7.9 mmol/l in the first trimester to 7.3 in the second and 6.4 in the third. Mean percentage of haemoglobin A1 was within the normal range in the second and third trimesters. The cesarean section rate was high at 66% but there were no perinatal deaths. Three infants had congenital abnormalities. We conclude that home blood glucose monitoring is a safe and effective way of managing pregnant diabetic women as out-patients. The cost of meters and sticks is repaid many times over in the saving of hospital costs. In addition, home blood glucose monitoring is popular with the patients and many choose to continue it after delivery.

Insulin and glucose requirements during the first stage of labor in insulin-dependent diabetic women

Studies utilizing glucose-controlled insulin infusion systems were undertaken to more accurately define the glucose and insulin requirements during the first stage of labor induced by oxytocin in 12 insulin-dependent diabetic women in whom normoglycemia had been maintained before delivery. Insulin requirements decreased to zero during active stage 1 labor, while the glucose infusion rate necessary to maintain a blood glucose level of 70 to 90 mg/dl (or 3.9 to 5.0 mmol/liter) was constant at 2.55 mg/kg per minute. The findings were confirmed in 40 additional studies of oxytocin-induced labor. Studies of six women undergoing spontaneous labor and one nonpregnant woman receiving oxytocin confirmed that the decrement in the insulin requirement during stage 1 labor was not influenced by oxytocin infusion. The changes occurred regardless of whether epidural anesthesia was employed. Insulin requirements returned during the second stage of labor. Active stage 1 labor in diabetic women thus appears to be associated with a predictable decrease in the need for insulin and a constant glucose requirement.

Use of low-dose insulin infusions in diabetics after myocardial infarction

Myocardial infarction in diabetics is often accompanied by poor diabetic control. An assessment of a low-dose insulin infusion regimen in 26 diabetic patients after myocardial infarction found this system to be simple, effective, and safe.

Insulin requirements during labor: a reappraisal

Continuous insulin infusion has been advocated for strict glucose control during labor in insulin-requiring diabetic patients. We studied 33 insulin-dependent diabetic patients who were at term and undergoing induction of labor with oxytocin. Each patient received a glucose infusion (6 gm/hr), and the blood glucose level was determined hourly. Blood glucose levels did not rise above 100 mg/dl in 16 patients (48.4%) despite continuous intravenous glucose infusion. No differences were found in the following parameters between these patients and those requiring insulin infusion: maternal age, weight, diabetic class, gravidity, and prior insulin requirement. Birth weights and the incidence of neonatal morbidity were similar between groups and occurred despite euglycemia during labor. We found that euglycemia during labor did not prevent infant morbidity irrespective of the use of continuous low-dose insulin infusion. Additionally, 48% of patients did not require any insulin during induction of labor despite large antenatal insulin requirements.

A method for maintaining normoglycemia during labour and delivery in insulin-dependent diabetic women

The effectiveness of combining the subcutaneous administration of short- and intermediate-acting insulin with the intravenous infusion of glucose in maintaining normoglycemia during labour and delivery in insulin-dependent diabetic women was tested. Fifty women were given intermediate-acting insulin twice daily in doses that were fractions of their usual dose, based on the projected duration of labour. In addition, they were given regular (i.e., short-acting) insulin every 6 hours, the dose being 1% of their total daily insulin dose for every increase of 10 mg/dl above 100 mg/dl (5.6 mmol/l) in the plasma glucose level 1 hour previously; the levels were measured every 3 hours. All the patients were fasting and received a basal intravenous infusion of 6 g/h of glucose; the rate of infusion was increased by 1 g/h for every decrease of 10 mg/dl in the plasma glucose level below 100 mg/dl. The mean plasma glucose levels (+/- standard deviation) were 90 +/- 46 mg/dl after 3 hours of labour, 92 +/- 35 mg/dl after 6 hours, 97 +/- 49 mg/dl after 9 hours and 107 +/- 65 mg/dl after 12 hours. With only one exception, in a premature infant, the 5-minute Apgar scores were identical to those of the infants of nondiabetic women.

Self-monitoring of blood glucose in diabetic pregnancy

Admission to hospital is usually recommended to achieve the best possible diabetic control during pregnancy. We have used blood glucose monitoring at home to find out if patients can achieve equally good control outside hospital. Twenty-five consecutive diabetic patients were studied, of whom 20 had taken insulin before pregnancy. Six of their 14 previous pregnancies had ended in perinatal death. The 25 women performed 4247 blood glucose measurements during their pregnancies. Overall the mean blood glucose concentration was 7.1 mmol/l (128 mg/100 ml); before meals the mean was 6.5 mmol/l (117 mg/100 ml). Mean concentrations were lower in the third trimester, but at no stage was control in hospital significantly better than at home. The mean hospital stay before delivery was 22 days, and all patients had live babies. Monitoring blood glucose concentrations at home produces greater understanding and motivation among patients, improves control early in pregnancy, and shortens time spent in hospital.

Intravenous insulin infusion in diabetic emergencies

Continuous intravenous insulin and dextrose infusions were used in managing various diabetic emergencies. Standard and constant rates of insulin and dextrose infusion resulted in satisfactory control of blood glucose concentrations during labour, after major surgery, and in patients recovering from ketoacidosis (average insulin infusion rates 1, 2, and 3 U/h respectively). Higher infusion rates were used to correct or prevent ketoacidosis in pregnant diabetic women who had received steroids and sympathomimetic agents. The infusion method is simple, reliable, and flexible, and may help to simplify management of diverse types of diabetic emergencies.

Studies with a pancreatic beta cell simulator in the third trimester of pregnancies complicated by diabetes

To determine the potential of an artificial pancreatic beta cell simulator as a therapeutic and research tool we have used the device for short-term monitoring and control of blood glucose concentrations in five pregnant patients with juvenile-onset diabetes (White's Class C) and three pregnant patients with maturity-onset diabetes (Class B). One patient with brittle juvenile-onset diabetes had successful control before, during, and after cesarean section. The other seven patients were studied during the third trimester of pregnancy and at least four weeks before delivery. Blood glucose control with Biostator regulation was excellent (mean, 96 mg. per deciliter; range, 85 to 107). The insulin requirements needed to achieve optimal glucose control with the Biostator were highly variable (range, 20 to 157 U. per 24 hours) but very similar to those previously calculated to provide optimal control by conventional means. Insulin requirements were unrelated to plasma growth hormone, placental lactogen, or glucagon concentrations. The greatest degree of insulin resistance was seen in obese patients with endogenous insulin-secretory capacity. This study indicates that a pancreatic beta cell simulator can normalize glucose concentrations and rapidly estimate daily insulin requirements in pregnant diabetic patients. In addition, the data suggest that exogenous insulin may indirectly suppress endogenous insulin secretion and thus contribute to the "insulin resistance" of obese patients with maturity-onset diabetes.

A glucose-controlled insulin infusion system for diabetic women during labour

A glucose-controlled insulin infusion system was used to control blood glucose concentration during labour or caesarean section in six insulin-dependent diabetics. The mean blood glucose concentration during the four hours of labour immediately before delivery was 4.6-5.2 mmol/1 (82.9-93.7 mg/100 ml). Feedback control of insulin delivery by blood glucose concentration should decrease the risk of postpartum hypoglycaemia in the infant and allow normal obstetric management for the insulin-dependent diabetic in labour.

Simplified management of pregnancy complicated by diabetes

Simple methods for the management of pregnancy complicated by diabetes are described. Emphasis was placed on keeping patients out of hospital, good control of diabetes and vaginal delivery at 38 weeks: using these methods, there were nine perinatal deaths in a consecutive series of 101 pregnancies complicated by diabetes. Four of the perinatal deaths were due to the respiratory distress syndrome. The patients whose diabetes was diagnosed during pregnancy had significantly heavier babies (18 pregnancies, mean birth weight 3337 g) than the established diabetics (83 pregnancies, mean weight 3011 g) despite significantly lower fasting blood glucose levels in the former and similar mean gestational ages at delivery. Mean fasting blood glucose levels for the whole series during the first, second and third trimesters were 9.0, 6.7 and 5.6 mmol/l respectively. The mean duration of antenatal stay in hospital for complications related to diabetes was 29 days. Diabetic retinopathy did not seem to be adversely affected by pregnancy.

Self-monitoring of blood-glucose. Improvement of diabetic control

An accurate pattern of blood-glucose changes in everyday life is the basis for treatment in insulin-dependent diabetes. 69 patients were taught to obtain their own blood-glucose profiles with a 'Reflomat' Boehringer Mannheim) reflectance meter on one working and one rest day, and to repeat these where necessary after adjustment of treatment. 2 did not complete the study satisfactorily. The other 67 produced profiles on 241 dyas. Even patients with a limited education could use the technique accurately and their readings correlated closely with simultaneous laboratory values (r = 0.96). Self-monitoring was especially useful in elucidating problems in diabetic control, preventing hypoglycaemia, and managing diabetic pregnancy. Unlike the measurement of HbA1c which only detects poor diabetic control, self-monitoring also shows how to improve it. Patients found self-monitoring more informative than urine tests; their active involvement in management of their disease resulted in better motivation, greater understanding of diabetes, and a sustained improvement in control. By the end of the study 32 of the 67 patients ahd profiles in which no more than one blood-glucose value exceeded 10 mmol/l. Smaller and more portable machines will make the technique more widely applicable.

Clinical perspectives in the care of the pregnant diabetic patient

Despite the considerable improvement in the care of the diabetic mother and the prognosis for her baby, a number of clinical problems remain unresolved. Apart from the increased incidence of major and minor fetal anomalies, morbidity amongst the newborn and the high incidence of diabetes in later life of women who have had relatively minor carbohydrate intolerance during pregnancy are a cause for concern. In this paper the outstanding clinical problems and thier possible solutions are considered. The elucidation of the origin of congenital malformations is discussed. The prevention of congenital anomalies in the diabetic requires a precise knowledge of their aetiology which is currently not available. However, on the hypothesis that diabetes creates an abnormal biochemical environment which may well disturb embryogenesis, it is logical to try and control maternal blood sugar as soon as possible in pregnancy or even before conception. To extend this argument further, it follows naturally that the maintenance of normoglycaemia throughout pregnancy until delivery is also desirable. The practicalities of various methods of screening for diabetes in pregnancy and new approaches in the medical and obstetric problems of the pregnant diabetic are also considered. Finally, the question of contraception and its implication for the woman who is known to have carbohydrate intolerance in pregnancy is discussed.