Ethnicity is a particularly important factor determining incidence of GDM (eg, very high risk -- Australian Indigenous, Polynesian and South Asian [Indian] groups; moderate high risk -- Middle Eastern and other Asian groups).

When selective screening is deemed more appropriate because of known low GDM incidence, the ADIPS criteria are similar to those recommended by the American "Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus".²⁰ A recent article by Naylor et al²¹ derived a risk factor scoring system that excluded the need for screening up to a third of pregnant women. However, complex criteria for selective screening may cause difficulties in busy clinical practice.

A summary of the screening and diagnostic procedures recommended by ADIPS is given in the Table.

Diagnosis

The guidelines for diagnosing GDM in Australia are essentially unchanged from those recommended for use in Australasia in 1991.²² Although there are no uniform international criteria for the diagnosis of GDM, commonly used criteria are those of O'Sullivan and Mahan²³ and the World Health Organization (WHO).²⁴ One problem with the development of absolute diagnostic criteria is the lack of evidence that perinatal mortality is increased in pregnancies associated with mild degrees of hyperglycaemia. The commonly used diagnostic criteria were not formulated to assess the risk of adverse perinatal outcomes, although this was a factor taken into account in the diagnostic criteria at the Mercy Hospital for Women, Melbourne.⁴ The existence of different methods of performing glucose tolerance tests has also hindered the development of uniform diagnostic criteria for GDM.

After consensus, ADIPS has endorsed the diagnostic criteria developed by the working party chaired by Dr F I R Martin in 1991, which are modified WHO criteria.²² In New Zealand, the 2 hour oral glucose tolerance test (OGTT) cut-off value for a positive diagnosis is a venous plasma glucose level of 9.0 mmol/L. This figure was chosen by a majority decision of specialists at the 1992 meeting of the New Zealand Society for the Study of Diabetes. They chose the higher figure to reduce the worry and inconvenience for women of being given a false positive diagnosis and to reduce the strain on stretched specialist resources in many centers. ADIPS recognizes the importance of working towards an Australasian consensus on this issue.

If the clinical suspicion of GDM is high, a diagnostic OGTT is indicated, irrespective of the stage of pregnancy. In such circumstances, if an OGTT gives normal results early in pregnancy the test should be repeated between 26 and 30 weeks' gestation. A 75 g OGTT should use 75 g of anhydrous glucose or the equivalent, and preferably should also be performed after a high carbohydrate diet of at least 150 g of carbohydrate for three days.

Management of GDM

A team approach is ideal for managing women with GDM and, if available, should be used. The team would usually comprise an obstetrician, diabetes physician, a diabetes educator (diabetes midwifery educator), dietitian, midwife and paediatrician. In practice, however, the team approach is not always possible due to limited resources. In such circumstances, management by an obstetrician or obstetric general practitioner knowledgeable in GDM management, often with the assistance of an appropriately skilled dietitian, diabetes educator or midwife, is acceptable.

Patient education

The importance of educating women with GDM (and their partners) about the condition and its management cannot be overemphasised.

Compliance with the treatment plan depends on the patient's understanding of:

   1- The implications of GDM for her baby and herself;

   2- The dietary and exercise recommendations; and

   3- The how and when as well as the goals of self monitoring of blood  glucose level.

Care should be taken to minimise the anxiety of the women. control

Dietary therapy: Dietary therapy is the primary therapeutic strategy for the achievement of acceptable glycaemic control in GDM. All women should receive nutritional advice, preferably from an appropriately skilled dietitian. However, it is important to avoid a severe calorie-restricted diet, as this can predispose to ketonuria, and also to infants that are small for their gestational age, which carries an increased risk of diabetes in later life.²⁵

The diet needs to:

• Conform with the principles of dietary management of diabetes in general;
• Meet the nutritional requirements of pregnancy;
• Be individualised for each patient, depending on maternal weight and body mass index; and
• Be culturally appropriate.

Moderate exercise has recently been recognized as an adjunct therapy, with potential benefits when used together with diet, or diet and insulin therapy, in the management of gestational diabetes in women without a medical or obstetric contraindication.²⁶

Monitoring: Glycaemic control needs to be monitored. Self monitoring of blood glucose level is the optimal method and is well tolerated by most women. On commencement of self monitoring, at least one fasting and one 1 or 2 hour postprandial glucose level should be obtained daily. The frequency may be decreased or increased depending on the results of the blood glucose monitoring and the progress of the pregnancy. If self monitoring is not possible, fasting and 1 or 2 hour postprandial laboratory capillary blood or venous plasma glucose levels should be performed regularly (at 1 to 2 weekly intervals). In pregnancies complicated by GDM, the value of self monitoring of blood glucose and appropriate insulin therapy in the prevention of macrosomia and its associated perinatal complications has previously been demonstrated.^27,28 The minimum goals for glycaemic control are:

1. a fasting capillary (venous plasma) blood glucose level <5.5 mmol/L
2. a 1 hour postprandial capillary (venous plasma) blood glucose level <8.0 mmol/L
3. a 2 hour postprandial capillary (venous plasma) blood glucose level <7.0 mmol/L.

These minimum goals have been set on the basis of informed consensus opinion in Australasia and vary little from those of the American Diabetes Association clinical practice recommendations on gestational diabetes (fasting glucose 5.8 mmol/L and 2 hour postprandial plasma glucose 6.7 mmol/L).²⁹ The setting of minimal goals for glycaemic control is controversial, however, as some, but not all, studies show benefit from tight glycaemic control in women with GDM.^27,28,30-32 The reasons for the variance in results between studies may relate to differences in the underlying rates of GDM complications from one study population to another. The recommended fasting glycaemia goal of <5.5 mmol/L is supported by Langer et al, who have shown that rates of large-for-gestational-age (LGA) infants are increased in diet-treated GDM pregnancies if the fasting glucose level is between 5.3 and 5.8 mmol/L (28.6% LGA) compared with 5.3 mmol/L (5.35% LGA).³² Insulin treatment was shown to reduce the rates of LGA infants to 10.3% in GDM pregnancies with fasting glucose levels between 5.3 and 5.8 mmol/L.³² In support of the 1 and 2 hour postprandial glycaemic goals of <8.0 and <7.0 mmol/L, respectively, it has been shown that glycohaemoglobin (HbA_1c) levels, birth weight, and rates of macrosomia, neonatal hypoglycaemia and caesarean section (for cephalopelvic disproportion) can all be significantly reduced in insulin-treated GDM subjects if insulin therapy is adjusted according to 1 hour postprandial, rather than pre-prandial, glucose measurements, aiming for <7.8 mmol/L.²⁷

HbA_1c levels may be used as an ancillary test, as assurance that the self monitored blood glucose results are appropriate. Fructosamine levels are reduced during pregnancy because of the dilutional effect of pregnancy on plasma proteins. HbA_1c and fructosamine are not reliable substitutes for self monitoring of blood glucose level.

Insulin therapy: Insulin therapy should be considered if the blood glucose goals are exceeded on two or more occasions within a 1 to 2 week interval, particularly in association with clinical or investigational suspicion of macrosomia. However, the benefit of instituting insulin therapy after 38 weeks' gestation is unproven.

Human insulin should be used. No insulin preparations have a pregnancy category listing, except for the new, rapidly acting insulin analogue lispro, which is Category B2 (Australian medicines in pregnancy category). Two cases of congenital malformations were recently noted in women with insulin-dependent diabetes treated in pregnancy with lispro.³³ The number of women treated with lispro in pregnancy is small to date, but no causative relationship between lispro and teratogenicity has been documented. In general, the insulin preparations and dosage schedules should be tailored to the abnormalities present in the glycaemic profile (eg, postprandial and/or fasting hyperglycaemia) and patient acceptability. The doses may be higher than those required in non-pregnant subjects and should be reviewed frequently so that adequate glycaemic control is achieved rapidly. Care should be taken to minimize the risk of hypoglycaemia, especially nocturnal episodes.

Oral hypoglycaemic agents have no place in treatment of GDM under normal circumstances.

Fetal surveillance

The timing of commencement and the frequency of fetal monitoring in pregnancies complicated by GDM depend on the presence of other pregnancy complications such as pre-eclampsia, hypertension, antepartum haemorrhage and intrauterine growth retardation. The regimen chosen should be dictated by the severity of the obstetric complication. Monitoring may be by either Doppler umbilical bloodflow measurement or cardiotocograph (CTG). Although CTG surveillance is commonly undertaken routinely from around 36 weeks' gestation, there is no objective evidence that fetal monitoring in uncomplicated GDM affects fetal outcome.³⁴ Common practice in the United States is to commence CTG monitoring after 40 weeks' gestation, while awaiting spontaneous onset of labour in uncomplicated GDM pregnancies,³⁵ but again there is no evidence-based medicine to support or refute this practice.

Ultrasonography should be considered at around 34 weeks' gestation to detect abnormalities of fetal growth and polyhydramnios. It may be indicated earlier in some women, for example for women unsure of their dates, or those with morbid obesity or suspected undiagnosed non-insulin-dependent diabetes. Ultrasonography may need to be repeated if any abnormality is detected.

Timing of delivery

The possibility that diagnosis of GDM may lead to increased obstetric intervention, including induction of labour and caesarean section,³⁶ is a concern. Delivery before full term is not indicated unless there is evidence of macrosomia, polyhydramnios, poor metabolic control or other obstetric indications (eg, pre-eclampsia or intrauterine growth retardation).³⁷ Continuation of the pregnancy in uncomplicated GDM to 10 days beyond term is acceptable provided that indications from fetal monitoring are reassuring.  

Delivery

During labour, good glycaemic control needs to be maintained while avoiding hypoglycaemia. Lower insulin requirements are common during labour (often no insulin is necessary). Fetal surveillance is needed, as it is for any high risk pregnancy. A paediatrician should be present at the delivery if significant neonatal morbidity is suspected. The maternal blood glucose level should be monitored for 24 hours postpartum and, if indicated, continued for longer.   

Neonatal management

The neonates of mothers with GDM are at risk of all the complications of infants born to mothers with overt diabetes, particularly those infants born macrosomic (birth weight >4000 g).³⁸ The neonates should be observed closely after delivery for respiratory distress. Capillary blood glucose should be monitored at 1 hour of age and before the first four feeds (and for up to 24 hours in high risk neonates). Currently, some amperometric blood glucose meters are acceptable for use in neonates, provided that suitable quality control procedures and operator training are in place. A neonatal blood glucose level <2.0 mmol/L needs to be verified by repeat testing (laboratory verification is preferred but should not delay the initiation of treatment). Levels <2.0 mmol/L should be considered abnormal and treated. If the baby is obviously macrosomic, calcium and magnesium levels should be checked on Day 2. Breastfeeding is actively encouraged.  

Maternal follow-up

It is important that women with GDM be counselled with regard to their increased risk of developing permanent diabetes. They should be made aware of the symptoms of hyperglycaemia. Advice should be given about the importance of healthy eating and exercise patterns. Contraceptive advice should be given in the puerperium, and women should be advised to plan future pregnancies and be reviewed medically by their general practitioner before conception (a pre-conception OGTT should be considered).

An OGTT, using WHO criteria for the non-pregnant population, should be performed at 6-8 weeks' postpartum to exclude permanent diabetes. Repeat OGTTs should be performed at least every two years (possibly at the same time as the cervical cancer screening). Impaired glucose tolerance merits careful follow-up, which should include at least twice-yearly checks for frank diabetes in addition to assessment of other risk factors for macrovascular disease.

The rates of development of permanent diabetes are much higher in several non-European ethnic groups. For example, the prevalence of type 2 diabetes in Polynesian women having a postpartum OGTT has been reported to be 30%.³⁹ Life-table analysis in a cohort of Latino women shown to have normal glucose tolerance in the postpartum period after pregnancy complicated by GDM revealed a 47% cumulative incidence of type 2 diabetes 5 years after delivery.⁴⁰ Similarly, 62% of women in Trinidad have been reported to develop type 2 diabetes after 3.6-6.5 years of follow-up.⁴¹ Follow-up OGTTs, therefore, should be more frequent than every two years in those groups at highest risk. 

ADIPS emphasises that, due to a lack of good quality randomised controlled clinical trials in the area of GDM, these guidelines are based on what is a reasonable consensus of informed opinion in Australasia. They are designed as a guide to practical management rather than a strict protocol. It is expected that the guidelines will not be static but will evolve as the results of clinical trials become available.

Carefully designed, randomized controlled clinical trials are needed in order to determine:

   1-Whether universal screening programs are warranted;

   2-The optimal criteria for diagnosis of GDM;

   3-The costs v. benefits of the team approach;

   4-Optimal management (eg, clarification of the indications for insulin therapy);

   5-The role of follow-up programs for affected mothers and babies; and

   6-Possible interventions to reduce the rates of development of permanent diabetes in the mother. 

One such trial is the prospective Australasian Carbohydrate Intolerance Study in Pregnancy (ACHOIS), which aims to clarify what degree of maternal hyperglycaemia results in specific adverse outcome. In the design of these trials consideration needs to be given not only to perinatal outcome, but also to the potential long term benefits of diagnosis and treatment for both the baby and the mother.     

'Diabetes risk' for lateborn babies

First born children of older mothers are at greater risk of developing diabetes, say researchers.

Professor Edwin Gale and colleagues at Southmead Hospital in Bristol looked at 1,375 families in the Oxford area in which one or more child had diabetes.

They found that the mother's age at the time of delivery was strongly related to the risk that the child would go on to develop type one (insulin dependent) diabetes before the age of 15.

The risk increased by 25% for each five years of the mothers' age, so that a 45-year-old mother was more than three times likely to have a child who developed diabetes than a 20-year-old mother.

To a lesser extent the risk of diabetes was also linked to older fathers.

Second children and their younger brothers or sisters were progressively less at risk of developing the condition.

Throughout the country women are in general having their children at an older age: between 1970 and 1996 the proportion of children born to mothers aged 30-34 years increased from 15% to 28%.

Diabetes increase

The authors of the British Medical Journal paper say: "The increase in maternal age at delivery in the UK over the past two decades could partly account for the increase in incidence of childhood diabetes over this period."

Researcher Dr Polly Bingley said the reason why the risk of diabetes fluctuated was unknown, and that further research was required.

Older mothers are known to have a higher risk of having babies with some conditions caused by damaged genes, but in this case there was no evidence of genetic abnormalities.

Dr Bingley told BBC News Online: "It appears some non-genetic factor is influencing the unborn child in uterus.

"It may be an interaction between the mothers immune system and the developing immune system of the unborn child, or it may be due to changes in placental function as the mother gets older."

Dr Bingley stressed that type one diabetes was still a relatively rare condition, affecting 3.5 children in every 1,000.

A spokesman for the Diabetes UK said: "There has been an alarming increase in type one  

diabetes in recent years, and the problem is that we don't know why this should be is possible

 -Hormones during pregnancy

1-Estrogen  is secreted by ovaries and placenta .Estrogen has a weak direct ant-insulin effect of increasing cortisol level which in turn has the strongest anti-insulin effect. Estrogen would stimulate the formation of globulin that binds cortisol in the liver thus increasing cortisol production .Hypercortisolemia would result in insulin resistance and delayed glucose    secretion, thus increasing glucose use by the fetus

2- HPL is a placental hormone that induces insulin resistance and carbohydrate intolerance. HPL also breaks down maternal lipids into free fatty acids that are used to provide fuel for the fetus.

3-Pregnancy  and age both are diabetogenic factors

4-islam orders to get marry  when they are young

5-The pregnant should  do prayer and fasting if no harmful for here or to her fetus to control insulin resistance .

6- female doing prayer for 25 days a month and take rest during menstruation cycle but pregnant female  will do prayer for 30 days monthly these will help pregnant to control the effect of diabetic hormones which occurs during pregnancy .