Gestational diabetes raises the risk of postnatal depression in first-time mothers, according to a large study into the subject.
Researchers also established that women with a history of depression were more than 20 times more likely to experience postnatal depression than mothers without a previous clinical diagnosis of depression.
“Having diabetes during pregnancy makes it 70% more likely that they will develop PPD”
In addition, while gestational diabetes alone increased risk for postnatal depression, a history of maternal depression in conjunction with gestational diabetes further increased the likelihood of postnatal depression.
The study represents the largest ever population-based piece of research to characterise postnatal depression in relation to depression history, involving more than 700,000 women.
The findings, by researchers from the Icahn School of Medicine in the US and the Karolinska Institutet in Sweden, have been published in the journal Depression and Anxiety.
In addition to gestational diabetes, the researchers studied other risk factors, including pre-gestational diabetes, for association with postnatal depression in women with and without a history of depression.
Among women with a history of depression, pre-gestational diabetes and mild preterm delivery increased risk.
Meanwhile, young age, instrument-assisted or caesarean delivery, and moderate preterm delivery increased risk in women who had no history of depression.
The researchers said that studying the modifying effect of maternal depression on pre- and perinatal postnatal depression risk factors shed new light on the relationship between diabetes and depression.
Showing that a history of depression modifies some of the risks associated with obstetric and perinatal factors suggests there may be different causal pathways of postnatal depression in women with and without a history of depression, they said.
Lead study author Dr Michael Silverman said: “Most practitioners think of gestational diabetes and postpartum depression as two isolated and very different conditions, but we now understand they should be considered together.
“While having diabetes increases postpartum depression risk for all women, for those women who have had a past depressive episode, having diabetes during pregnancy makes it 70% more likely that they will develop postpartum depression,” he said.
“With this information, we can now intervene early, before the mother gives birth,” he added.