How gestational diabetes can affect mental health

Gestational diabetes, or diabetes during pregnancy, is a growing problem in Aotearoa New Zealand and around the world. Women with gestational diabetes are at heightened risk of mental health problems, and should be considered for routine mental health screening.

Overall, it’s estimated one in 16 New Zealand women will experience gestational diabetes, but non-Pākehā women, and particularly those from Asian/Indian and Pacific backgrounds, are disproportionally affected. Among these ethnicities, up to one in five women may develop gestational diabetes, according to data from Auckland City Hospital.

Worse, between 2013 and 2021 there was a 60 percent increase in the incidence of gestational diabetes from about 9 percent to about 14 percent of pregnant women.
This is a serious problem. Gestational diabetes predisposes mothers and their babies to a number of health risks. Women are more prone to complications such as birth injuries and giving birth by caesarean delivery, because their babies are likely to be big. There is also a risk that after delivery, the baby may experience fast and shallow breathing.

Worryingly, up to one in two mothers with gestational diabetes go on to get type 2 diabetes later in life, with the accompanying risk of kidney and heart disease, and eye problems.

But there is a lesser-known problem that gestational diabetes affects mental health.

My research into women across 10 hospitals in Aotearoa New Zealand shows one in four reported at least one mental health disorder – having symptoms of anxiety, depression or poor mental functioning in accomplishing daily activities. One in eight reported symptoms of all three symptoms at the same time after a gestational diabetes diagnosis.

Here too, there are ethnic differences. Pacific mothers are twice as vulnerable to depression than Pākehā mothers during pregnancy, with younger and older mums also being particularly vulnerable.

We may expect having diabetes could make you feel worried, anxious and depressed for yourself and your baby; feelings of guilt, worry and self-blame are common when women are diagnosed with gestational diabetes. But research shows there are also biological links between diabetes and mental health.

High levels of glucose in the blood can disturb normal brain functioning and cause inflammation in the blood vessels of the brain, and a number of studies over the last decade have linked inflammation in the brain with clinical depression.

In addition, when people have diabetes their insulin production doesn’t work well, and insulin is needed for proper functioning of the brain. In some cases, high glucose and insulin disturbances found in diabetic patients results in hormonal imbalances similar to those seen in people with depression. This suggests there are shared physiological pathways between depression and diabetes.

These hormonal imbalances can also cause disturbance in sleep patterns, a common symptom of depression and anxiety.

The good news is that when glucose levels are well-controlled, mental wellbeing improves. This is why we need screening for women who have gestational diabetes.

Unfortunately, few countries routinely screen for mental health problems in women who get gestational diabetes, including in New Zealand. Germany is one of the few that does, recommending that the mental wellbeing of women who get gestational diabetes should be checked using a wellbeing questionnaire, and if found to be at risk for poor mental health they are referred on for further care.

This approach should be considered in Aotearoa New Zealand and tailored to our health system needs. Screening women who are at an increased risk of poor mental health – for example non-Pākehā women, those who have had diabetes in previous pregnancies, young mums, and older pregnant women – would be a good start.

This would ensure women are supported to thrive physically and psychologically during their pregnancies.

We also need to improve mental health services for the most at-risk women, by providing culturally appropriate mental health services for Pacific and Asian women in pregnancy and up to 12 months after birth.

As well as checking for poor mental health for women during their pregnancies, mental health screening should also be done three months after they give birth. At this time, it is recommended that women who had gestational diabetes get their blood sugar levels checked (though that isn’t always followed through as well as it should be).

A mental health screening test would be a straightforward way to ensure any developing mental disorders are identified and managed in time, helping secure the health of both mother and baby in the present and future.