HG and Gestational Diabetes
This is about gestational diabetes only. If you have Type 1 or Type 2 diabetes, and also have HG, please ask your GP for a referral to hospital early in pregnancy as your HG will need to be managed closely. You can see the HSE guidelines on diabetes and GDM in pregnancy here.
What is Gestational Diabetes?
Gestational Diabetes Mellitus (GDM) is a relatively common condition that occurs during pregnancy. It usually starts after 20 weeks. It is related to poor processing of sugars in the body because of pregnancy hormones and not being enough insulin being made. Insulin is a hormone that helps the body to break down sugars. If you have GDM, there are high levels of sugars in the your body. These normally do not cause symptoms in pregnancy which is why a screening test is important. High levels of sugar in the body can lead to complications during and after the pregnancy for you and for the baby if not treated. This is why it is important to screen for GDM if you have risk factors.
Most hospitals in Ireland will screen those who have risk factors for GDM such as a body mass index (BMI) >30, polycystic ovarian syndrome (PCOS), being over 35 years in age, or a family history of Type 2 Diabetes. A smaller number of maternity units will screen everyone for GDM.
Unfortunately, it’s possible to have both HG and GDM. If you are on steroids as part of your HG treatment, this also increases the risk of developing GDM.
What does the screening involve?
Screening for GDM is generally done between 24-28 weeks. Generally, the test is done early in the morning and it involves fasting beforehand (overnight). On arrival at the hospital, you will have a blood test. You will then drink a sugary drink and stay resting while awaiting further blood tests at 1 hour following this drink, and again at 2 hours following the drink. It is recommended not to be active during the waiting period between bloods as exercise will reduce your blood sugar level. Once these two blood tests are taken, you may leave. Usually the hospital will be in touch in the case of a positive result only (indicating that you have GDM).
Some units may do a two-stage screening - ask your unit what their process is.
What about when you have HG?
Understandably, you may be apprehensive about both the need to fast and the need to consume a sugary drink during the test.
You should contact your antenatal unit in advance and ask them about:
- Taking your regular medications on the morning of the test. Tell them you are concerned about vomiting - if you vomit during the 2h window the test is not valid.
- Getting an injection of anti-sickness medication to help ensure you don’t vomit.
- Having a quieter space to sit in, or a bed to rest on, can help keep nausea to a minimum.
Your hospital should be able to give you a different way of doing the test if their usual protocol won't work for you. For example:
I wasn’t able to take the drink without vomiting it up, so I was brought back a few days later. I fasted overnight, had my first blood test taken to check my fasting sugar levels and then I was given a slice of toast. After the toast, they took just one blood test. This was sufficient for them to check for GDM.
- Dr Naomi Smith, HI trustee, GP, and HG patient x2
What if you get diagnosed with GDM?
Firstly, don’t panic. The midwives and doctors will have met others in your situation. Secondly, please be kind to yourself as it is tough to have to deal with both of these conditions.
A diagnosis of GDM is usually managed to begin with by changes to your diet and increasing your physical activity, combined with checking your sugar levels yourself throughout the day.
A GDM diet focuses on:
1. Eating regular meals and snacks containing carbohydrates. Aim for 3 meals and 2-3 snacks per day.
2. Choosing the right type of carbohydrate foods. Choose slow release carbohydrates (like wholegrain bread, instead of white bread) and avoid foods high in sugar
3. Watching your carbohydrate portion size
Having HG and GDM can be really challenging, because often the foods that are your "safe foods" with HG, might not be recommended for GDM. For this reason, it is important to ask for a referral to a dietitian in your hospital to help you, to ensure that you are still eating enough, gaining weight appropriately, and managing your blood sugars.
It is also important to optimise the HG medication that you are on, so that you can eat well and manage your blood sugars.
If your sugars do not settle with changes to diet alone, tablets or insulin injections can also be used to help.
Further resources:
Diabetes Ireland: gestational diabetes information
Gestational Diabetes UK information on coping with GDM and HG
Evidence-Based Birth: information on screening for gestational diabetes
Diabetes in Pregnancy: a model of care for Ireland (HSE - aimed at healthcare providers).
HSE guidelines on management of diabetes in pregnancy
