What is gestational diabetes?
Gestational diabetes is the diabetes mellitus that develop for the first time during pregnancy. It disappeared 6 weeks after delivery.
How does it occur?
During pregnancy, the placental secretes 3 anti-insulin hormones ® estrogen, hPL(human placental lactogen) & cortisol. These hormones against the function of insulin (The function of insulin is to reduce the blood sugar level). To counter this effect, the pancreas produces and secretes more insulin. Thus, the level of insulin is raised by the action of the placental hormones, placing a burden on the insulin-secreting cells (pancreatic islets). The pancreas may be unable to meet these demands in women genetically predisposed to develop both types of diabetes.
There are 2 scenarios of diabetes in pregnancy:
· Established diabetes
Women who are already diabetic at the start of pregnancy (most cases)
· Gestational diabetes
Development of diabetes for the first time during pregnancy.
Gestational diabetes may or may not disappear following delivery. Repeated pregnancy may increase the likelihood of developing permanent diabetes, particularly in obese women. Studies have shown that some 80% of women with gestational diabetes ultimately develop permanent clinical diabetes requiring treatment.
How to confirm gestational diabetes?
It is diagnosed by a test, called Modified Oral Glucose Tolerance Test (MOGTT), which show raised blood sugar level.
Procedure for MOGTT:
• MOGTT should be done in the morning after at least 3 days of normal diet and usual physical activity
• The test should be proceed by an overnight fast of 10-16 hours during which plain water may be allowed
• Subjects should be at rest for the duration of test. Smoking is not permitted. The presence of factors that influence interpretation of the result of the test must be recorded. (e.g. medication, inactivity, infection)
• After collection of fasting blood sample, the subject is required to drink 75g of anhydrous glucose in 250-300ml water within 10 minutes
• Another blood sample must be collected 2 hrs after finishing glucose drink
It is confirmed if:
• Fasting blood sugar >7.0mmol/L or
• 2 hours Post-sugar - >11.1 mmol/L
1-2% of women will develop gestational diabetes and they are having risk to develop diabetes mellitus type 2 in future.
What are the risk factors?
• Women >35 years old
• Maternal obesity (BMI >30)
• Family background of diabetes mellitus among 1st degree relatives
• Previous history of big baby (>4 kg)
• History of gestational diabetes in previous pregnancy
• History of unexplained fetal death
• History of congenital anomaly in previous pregnancy
What are the symptoms?
• Usually no symptom
• Sometime may develop:
– Excessive passage of urine
– Extreme thirsty
– Excessive passage of urine at night or during sleep
– Extreme hunger
– Sweet smelling breath
– Unusual weight loss
What are the effects to the mother and the baby?
Effects to the pregnant mother
1. Pregnancy induced hypertension (2 times greater risk to develop hypertension compared to non diabetic pregnant mother and it is because of the effect of estrogen hormone and the abnormality of blood vessel)
2. Excessive amniotic fluid + premature rupture of amniotic membrane
3. Premature labour give rise to premature baby
Urinary tract infection (d/t high sugar level in the urine, therefore bacteria are more likely to grow)
Candidiasis of the vulva and vagina
Effects to the fetus/baby
1. Early pregnancy
Congenital anomalies (heart, limbs, spinal cord)
2. Later pregnancy
Big baby (more than 4kg at birth, it is because when the mother’s blood sugar levels are elevated, the sugar crosses the placenta and cause blood sugar level in fetus increased as well. The fetus in such a setting is “overfed” and grows large, with increased deposits of fat and glycogen. Large baby has a significantly increased risk for birth trauma. Besides that, high blood sugar level in fetus also causing overproduction of insulin in the fetus. Insulin promotes growth, therefore the fetus grow rapidly)
Fetal death (Due to poor oxygen delivery to the fetus)
Polycythemia (A condition marked by an abnormally large number of red blood cells in the circulatory system as a compensation of lack of oxygen.)+ hyperbilirubinemia (excessive bilirubin in blood due to excessive breakdown of the red blood cell and it cause jaundice)
3. After delivery
Low blood sugar level (Fetus exposed to high blood sugar level results in over production of insulin hormone. When it is delivered and the sugar supply is cut off but the insulin secretion persists, the infant can develop extremely low sugar level, especially during the early hours of life. This can be serious since the brain utilizes sugar as a major substrate. Prolonged low blood sugar level can produce brain dysfunction.)
Jaundice (yellowish discoloration of the whites of the eyes, skin, and mucous membranes)
Breathing difficulty (because of delayed fetal lung maturation and the harming effect of insulin hormone on lung maturation)
What should I do to prevent/ overcome this problem?
· Control maternal blood sugar levels
· Early delivery (at least not post date) in an appropriate site based on fetal heart testing and lung maturity
4 stages of precaution/ management:
- Preconceptual/ before pregnant
- During pregnancy
- During delivery
- After delivery
• Normal healthy diet (A balanced diet consisting of 50-60% energy from carbohydrate, 15-20% energy from protein and 25-30% energy from fats are encouraged. 35 calories /kg (body weight). A high fiber diet (20-30g fiber/day or 5-7 servings/day) consisting of vegetables, fruits, legumes and whole grain cereals is encouraged. Take low glycemic index food such as fruits, green leafy vegetables, beans, legumes, nuts, breads which are wholegrain or wholemeal in nature, etc.) Avoid high glycemic index food such as white potatoes and white rice as they bring up the blood sugar level rapidly)
• Regular exercise (at least 3 days per week and 30 minutes per day)
• Maintain normal BMI (less than 30kg/m2)
• Medical counseling
• Assessment of risk factors
• Assessment of complications e.g. kidney function and eyes
• Control blood sugar to optimal level before conception
2. During pregnancy
What should I do if been diagnosed to have gestational diabetes?
• Early booking (first antenatal check up) & frequent follow up
• Start with diet control (take healthy diet as mentioned above)
• Check blood sugar profile (BSP) at clinic 2 weeks later, start on insulin therapy only if BSP more than 6.7, otherwise continue diet control
• Consult your doctor about the type and the dose of insulin
• Self monitoring of blood sugar level
• Maternal assessment (blood sugar profile, urine sugar level, body weight, blood pressure, urine protein)- look for diabetic status & screen for hypertension
• Fetal assessment
- Early ultrasound for dating in the 1st trimester
- Detailed ultrasound for fetal abnormality at 18-20 weeks
- Serial scan (Fortnightly) for fetal growth. Include measurement of head circumference and abdominal circumference
- Regular monitoring of fetal well being on weekly or two weekly in 3rd trimester, by biophysical profile together with fetal heart monitoring
- Monitor fetal kick count (normal count is at least 10 kicks per day)
How frequent should I go for antenatal follow up?
• Antenatal visit 2 weekly till 32 weeks, weekly after that until delivery
Should I been admitted to hospital?
It is indicated when:
• The diabetic status is poorly controlled
• When need to adjust the insulin dose
• For blood sugar profile
• Complications occur eg. Mother develop hypertension, fetal compromise (showed in ultrasound scanning or reduced fetal kick count)
• When delivery is indicated
3. During delivery
When to deliver?
• If diabetic is optimally controlled with diet only, can deliver at the estimated date of delivery (40 weeks, but not post date as the fetus will grow bigger with duration and causing difficulty in delivery later)
• If diabetic is optimally controlled with diet & insulin, deliver at 38-40 weeks is recommended (as fetal lung maturation is completed after 38 weeks)
• If not well controlled & associated with fetal compromise, delivered before 38 weeks ( make sure the mother is given dexamethasone before delivery, which is helping in fetal lung maturation)
What are the methods of delivery in gestational diabetes?
• Normally vaginal delivery is recommended if absence of any complication
• Consider operation if:
– Big baby (more than 4kg)
– A previous operation delivery
– Abnormal head position
– Size of the fetal head larger than the pelvic outlet
– Excessive amniotic fluid
– Evidence of fetal compromise
– Bad obstetric history
– History of infertility
– Poor diabetic control
– Vascular complications
4. After delivery
• Monitor blood sugar (glucostix) 6 hourly for 1 day
• Repeat MOGTT 6 weeks after delivery ( normally blood sugar level return to normal 6 weeks after delivery, if it still persisted that means the mother is having permanent diabetes and she need treatment)
• Contraception (at least 2 years recommended to ensure good spacing)
• Early antenatal booking for the future pregnancy
• The baby should be observed closely after delivery for respiratory difficulty
• Blood sugar should be monitored at 1 hour of age and before the first four feeds (and for up to 24 hours in high risk baby)
• Levels <2.6 mmol/L should be considered abnormal and treated
• Breastfeeding is actively encouraged as human breast milk is the best source of immunity & it promote mother-baby relationship
Can I take oral contraceptive pil (OCP) if I am having permanent diabetes?
• OCP is not recommended for diabetics because combined contraceptive pill increase the risk of vascular complications while progesterone-only pills is associated with irregular menstrual flow and higher failure rate
• Barrier method is the best option eg. Condom
• IUCD (intrauterine contraceptive device) is also not recommended in diabetics since there is an increase chance of infections