Study shows blood glucose levels need not influence people’s decision to breastfeed

What did the study measure?

The study, by Lois Donovan, has been recently published to investigate the impact higher blood glucose levels would have on growth of infants and volume of breast milk consumed. They measured many variables, such as the different sugars in the breast milk (glucose, fructose and lactose), alongside measuring for a hormone called leptin. Leptin is produced by fat cells and helps to regulate energy balance in the body and is often associated with controlling body weight.  

What were the results?

Both studies showed that increased blood sugar concentrations of glucose and fructose had no impact on weight gain of the infants, and it had no impact on volume of milk ingested. Lactose was not included here as levels of this sugar do not change between people with T1D and those without. There was a correlation in both studies between levels of leptin in breast milk, BMI of the mum and volume of milk consumed. 

These results provide much needed information and reassurance for  with T1D and supports that their pre-feed blood glucose does not need to influence their decisions to breastfeed. Larger studies are still required for this type of research.  

Why can breastfeeding be more difficult with T1D?

For people with T1D, navigating pregnancy can be challenging with tighter blood sugar targets, higher insulin requirements and increased hospital appointments. When the baby is born, insulin needs return to that of pre-pregnancy, however managing this after nine months of a different regime can be difficult. Blood sugars can be expected to fluctuate, meaning HbA1C levels or time in range may change.  

Breastfeeding uses up a lot of energy and calories, meaning there is an increased risk of low blood sugar (hypoglycaemia). It is well advised to keep some carbohydrate-based snacks in easy to reach places while breastfeeding to avoid this. Our pregnancy toolkit contains lots of useful information on this subject.  

During hypoglycaemia, it can be easy to overeat, which would lead to higher blood sugars (hyperglycaemia). There may then be a feeling that they should not then breastfed until their sugars are in a better range, for a fear of giving the baby too much glucose via the breastmilk. 

Get support

Breakthrough T1D has many resources to support women with T1D during their pregnancy, including a pregnancy toolkit, which gives information and support to women going through pregnancy and breastfeeding.