Diabetes

Gestational diabetes

If you have been diagnosed with gestational diabetes, it is because it has been found that you have a higher than normal level of glucose (sugar) in your bloodstream. It is called gestational diabetes because it has been found whilst you are pregnant.  In a small amount of cases, it may be that a woman has undiagnosed diabetes, not caused by pregnancy.  The only way to know this is after your baby is born.  If your blood glucose remains high or uncontrolled postnatally then it is likely you have type 2 diabetes, your GP will check this at your eight week postnatal check.

Diabetes is when the insulin in your body is unable to unlock the glucose from your cells and use it as energy, therefore the glucose in your bloodstream builds up.  Women are more likely to become diabetic during pregnancy because from around 20 weeks gestation the growth hormones produced by the placenta, which encourage baby to grow can slow down the production of insulin.  To compensate for this your pancreas will release more insulin.  However in some women, this doesn’t happen very effectively, meaning there isn’t enough insulin to release the energy from the glucose you ingest.

Some women will be diagnosed with gestational diabetes and manage to keep their blood glucose levels within normal limits by a change in diet and lifestyle.  However, some women will struggle to control their blood glucose levels and will need insulin tablets or injections.  The risks associated with gestational diabetes are difficult to determine for these two sets of women because the majority of research that has been carried out has not separated the two groups.  However, it is known that the risk comes with uncontrolled blood glucose levels, not simply with the diagnosis of being a gestational diabetic.  If a woman manages to keep her blood glucose levels in a normal range then she is at no more chance of experiencing a complicated pregnancy and birth than a woman who does not have gestational diabetes.

One of the main concerns that caregivers have about women with gestational diabetes is that baby will grow too big.  If the mother has high glucose levels this will go through to baby.  Baby will then produce more insulin than normal to help break the glucose down.  A consequence of this is that baby’s organs will grow more and will lay down more fat around his/hers upper body and shoulders. This in turn increases the chance of shoulder dystocia; shoulder dystocia is when the baby’s shoulder becomes stuck on the front of the mother’s pelvis once the head is born, and stops the rest of the baby being born.  This is an emergency as baby’s cord is being compressed once the head is born and it requires the caregiver to encourage the mother to adopt a different position and possibly do some internal manuevres (inserting fingers to try and dislodge the shoulder).  This can sometimes cause injuries to the baby and be a traumatic experience for the woman.

Women with gestational diabetes who have normal blood glucose levels

If you have normal blood glucose levels throughout your pregnancy, you are not at risk of baby growing too big as baby is not receiving excess levels of glucose through the placenta.  The World Health Organisation advise that women with normal blood glucose levels should not be offered an induction of labour or caesarean section (31), whereas NICE guidelines advise women to have given birth by 40+6 (ref 32).  However, the evidence used by NICE doesn’t differentiate for normal and abnormal glucose levels. 

Women with high blood glucose levels

If you have uncontrolled blood glucose levels, this can make other conditions in pregnancy more likely, pre-eclampsia is one of these.  If this is true in your case, please also read the information sheet on pre-eclampsia.  It also makes the likelihood of developing type 2 diabetes later on in life, higher.  As detailed above, the main risk for baby is that baby may be big and the chance of shoulder dystocia happening is increased.  The insulin can delay the production of surfactant – this is an important substance that baby produces to help their lungs inflate.  Therefore some babies born to mother’s with high blood glucose levels can have some problems breathing after birth, especially if they have been induced at an earlier gestation or been born by elective caesarean section.