Pregnant question

Gestational diabetes is on the increase but the criteria for diagnosing the potentially dangerous condition are still the subject of debate.

- Nicky Pellegrino

Growing numbers of women are developing gestational diabetes. The condition affects about 6% of all pregnancies in New Zealand and that rate J is expected to rise, driven at least in part by an increase in obesity and a trend towards having children at a later age. This is bad news for the health of some mothers and their babies.

If there is excess sugar in a woman's bloodstream, it can lead to especially large babies and the potential for birth complications. There is a chance of shoulder dystocia - where the size of the baby's shoulders impedes the birth - and the child can have dangerously low blood sugar levels after birth, creating a risk of developmental problems.

Gestational diabetes also raises the risk of pre-eclampsia - a blood pressure condition that is potentially life-threatening for mother and child. And about half of women will develop Type 2 diabetes within 10 years of the pregnancy, while the infant will be at increased risk of obesity, diabetes and heart disease later in life.

If you have gestational diabetes it pays to find out sooner rather than later, but there has been a problem a lack of consensus over exactly where the threshold for diagnosis should lie. Some countries use a lower blood-sugar level than New Zealand does.

However, there has been uncertainty over whether this lower threshold brings a benefit, or if it unnecessarily labels women with a condition and puts further burden on the health service.