Gestational diabetes: can it affect my baby and me? What should I do?
Gestational Diabetes Mellitus (GDM) is an abnormal response to blood glucose levels, which may be initially diagnosed during pregnancy, in the second trimester in particular. It is amongst the most frequent pregnancy complications and may affect around 1 in 6 pregnancies. In this article we shall examine the causes, how it could affect your baby’s health or your own and what could be done to manage it.
1. What causes GDM?
GDM, as with regular diabetes, is caused by a dysfunction in glucose metabolism, with the added contribution of the placenta and fetus, which exacerbate it, by further increasing blood glucose levels.
2. Which women are more vulnerable? What are the risk factors?
The following are known risk factors for developing GDM:
- Advanced reproductive age (>40 years)
- Obesity (BMI>30 kg/m2)
- Family history of diabetes
- Personal history of GDM during previous pregnancy
- Latin, Asian or African descent
- Increased birth weight of previous baby (> 4,000 g)
- History of maternal, embryonic/neonatal complications (congenital abnormalities, polyhydramnios, intrauterine death etc)
- Multiple pregnancy
- History of recurrent miscarriage
- Polycystic ovary syndrome
- Sedentary lifestyle
3. Are there any warnings signs?
It is quite challenging to detect GDM based only on clinical findings, as it most frequently is asymptomatic (no noticeable symptoms) or its mild symptoms are considered part of the course of pregnancy. However, some women notice the following symptoms:
- Polyuria (frequent urination, large quantity of urine)
- Weight loss
- Frequent infections (vaginal, urinary tract infections)
4. Is it dangerous?
GDM could seriously impact your and your baby’s health and could cause severe disorders. Namely, GDM has been known to cause the following embryo/neonate complications:
- Large foetus (macrosomia) or small foetus
- Foetal developmental disorders
- Neonatal delivery complication (hypoglycaemia, risk of Acute Respiratory Distress Syndrome, shoulder dystocia etc)
Additionally, there might be long term complication on your child, which potentially may include:
- Psychological disorders
Potential negative effects on the mother may include:
- Urinary infections
- Premature delivery
- Post-partum haemorrhage/infection
- Recurrence of GDM in future pregnancy (30-80%)
- Development of diabetes post-partum
- BMI increase
- Cardiovascular disease
5. What should I do?
The aforementioned effects of GDM are definitely quite unsettling, however the intention of these extensive lists is not to frighten but to educate and prepare. With proper medical management, you can have a normal pregnancy, without any of the above potential effects. This is why GDM awareness, close monitoring and adherence to your doctor’s instructions is of vital importance.
6. How will I know if I have GDM?
Most physicians check blood glucose levels, at the latest by 24th-28th weeks of gestation, regardless of risk factors. The following tests are usually recommended:
- Fasting glucose
- Oral Glucose Tolerance Test (OGTT)
- HbA1c test
Of the above tests, OGTT is the most reliable and is used more frequently both as the basis of diagnosis and to confirm the findings of the other two. Typically, the two-step 75 g OGTT may be used. The following table shows normal values for each test:
|Fasting glucose (8-hour fast)||<92 g/dl|
|1-hour measurement||<180 g/dl|
|2-hour measurement||<153 g/dl|
|HbA1c||< 6.5 % (ideally < 6 % in pregnancy)|
7. What is the optimal management of GDM?
GDM management is based on two principles: monitoring and control. Should GDM be diagnosed, constant monitoring, either self-testing, fasting glucose measurement by the physician or midwife, or even constant monitoring via implant is a must. Monitoring is vital as it is the only means of assessment of GDM’s severity and response to treatment, given the lack of distinct clinical symptoms in most cases.
Regarding control, management ideally starts with a more conservative approach, namely proper diet and exercise. These measures usually achieve satisfactory control in most patients and even if they are not successful on their own, they are always recommended along with medication. It may be safer and more effective for each patient to be assessed individually and offered individualized care, however some general recommendations may include:
- Reduction of daily caloric intake (33% reduction, 1600-1800 kcal per day), avoidance of very low caloric intake diets (<1500 kcal).
- Carbohydrates: 35-45% of daily caloric intake, minimum of 175g/day divided in 3-5 daily meals/snacks.
- Reduction of high glycaemic index foods (white bread, white rice, potatoes and fries, cakes, cookies, sweet treats, sweet fruits and sweetened dairy products)
- Consume at least 28 g of fibre per day
- Maintain/reduce body weight (dependent on initial BMI)
- Exercise: improves glycaemic control via insulin resistance reduction. Personalized exercise programs are more effective, however these are some general guidelines:
- Planned physical activity 30min/day
- Brisk walking or seated arm exercises after each meal
Should such measures not suffice, then medication may be recommended. Insulin is the treatment of choice and an endocrinologist should be consulted and continue monitoring for some time after the delivery as well.
Epilogue – Conclusion
Gestational Diabetes Mellitus is a common complication in pregnancy, which could have very severe consequences if left unmanaged. However, they may all be avoided with vigilance, timely diagnosis and effective management, by experienced physicians.