Gestational Diabetes Mellitus is a carbohydrate intolerance resulting in Hyperglycaemia of variable severity with the onset or first recognition during pregnancy. (WHO -1999)
We at King’s are aiming to achieve pregnancy outcome in the diabetic that approximates to that of the non-diabetic pregnant woman – St. Vincent declaration in 1989.
The pregnant mother will be seen within initial consultation giving advice on the diagnoses the outcomes and the management plan. They will be seen approximately every 2 weeks, or the frequency may change depending on the requirements of the individual. There is his close cooperation between the consultant diabetologist and the obstetrician and will be reviewed on same day and the case is discussed.
Most women with gestational diabetes have otherwise normal pregnancies with healthy babies.
Gestational diabetes can cause problems which require specialist care which we will provide. These problems may include:
- The baby growing larger and may lead to difficulties during the delivery and possibly increased chance of induced labour or a caesarean section. Increased amniotic fluid (the fluid that surrounds the baby) in the uterus, which can lead to premature labour or difficulties during
- It may increase the chances of premature birth before the 37th week of pregnancy and can lead to high blood pressure during pregnancy and pregnancy complications if not treated called Pre-eclampsia
- The baby may have low blood sugar or Jaundice yellowing of the skin and eyes
- It can increase risk of developing type 2 diabetes in the future.
The care for women with previously diagnosed gestational diabetes starts before pregnancy and continue during period.
Nearly 3% of women have diabetes before getting pregnant. 30-50% of women will develop diabetes within the next 28 years.
The diagnosis is made by an oral glucose tolerance test (OGTT). The result of this should be available when the rationale and methods of treatment are discussed with the woman.
Assess risk of GDM using risk factors in a healthy population. If women had GDM in previous pregnancy do 75g OGTT as soon as possible, if negative repeat again at 24-28 weeks. Other women with any other risk factors screen at 24-28 weeks by 2-hour OGTT with 75 g glucose load.
In women with a glucose (fasting or non-fasting) level of >11.0mmol/l do not perform a GTT. Refer urgently to the diabetic antenatal clinic.
Screening is advised for women at increased risk of overt diabetes based on:
- Body mass index ≥30 kg/m2
- Gestational diabetes mellitus in a previous pregnancy
- Glycated haemoglobin ≥5.7 percent (39 mmol/mol), impaired glucose tolerance, or impaired fasting glucose on previous testing
- First-degree relative with diabetes Type 1 or Type2
- High-risk race/ethnicity (eg, African American/ Latino American,/South Asian/Black Caribbean/Middle Eastern ethnic origin )
- History of cardiovascular disease
- Hypertension or on therapy for hypertension
- High-density lipoprotein cholesterol level <35 mg/dL (0.90 mmol/L) and/or a triglyceride level >250 mg/dL (2.82 mmol/L)
- Polycystic ovary syndrome
- Severe obesity, acanthosis nigricans
- Previous birth of an infant weighing ≥4000 g
- Previous unexplained stillbirth.
- Glycosuria, >1+, on 2 occasions
- Congenital abnormality in previous/present pregnancy
- Oral Glucose Tolerance Test in Pregnancy (OGTT)
- Large for dates fetus or increase fulids/ polyhydramnios.
- Polyhydramnios/ large for dates baby in current pregnancy
- Glycosuria, >1+, on 2 occasions
Performance of a Pregnancy Oral Glucose Tolerance Test (POGTT):
- If the patient is identified as having risk factors for GDM, perform a POGTT. This is usually performed at 24-28 weeks but may be performed at other times if clinically indicated.
- The POGTT must be performed in the morning.
- The patient should have 3 days of normal diet and must fast for 12 hours (usually from midnight) with only water to drink. Advice not to smoke or to chew gum.
- A fasting finger test sugar is taken before the formal OGTT. If ≤10 mmol/l /180 mg /dl proceed with OGTT. If >10/ 180 mg start BM monitoring and no need for OGTT.
Gestational Diabetes Diagnosis on OGTT:
- Fasting Blood sugar 5.6mmol/l or 101 mg/dl
- 2 hour Blood Sugar 7.8mmol/l or 140 mg/dl
The pregnant mother will be seen within initial consultation giving advice on the diagnoses the outcomes and the management plan. They will be seen approximately every 2 weeks or the frequency may change depending on the requirements of the individual. There is his close cooperation between the consultant diabetologist and the obstetrician and will be reviewed on same day and the case is discussed.