Research out of Finland, published in August 2018, has established for the first time a close association between gestational type 2 diabetes (GDB) and an increased risk of postpartum depression (PPD).
While it has already been established that there is a link between general type 2 diabetes and depression, this new study looked specifically at diabetes that occurred during pregnancy as a potential cause for developing depression after birth.
GDB and PPD are both highly prevalent in perinatal conditions. In Finland, during the past five years, the 12-month prevalence of GDB has been reported at 9-13 percent, and worldwide the figures are as high as 17.8 percent. 10-15 percent of mothers are affected by PPD – representing a risk to a healthy mother-baby relationship and long-term impact on infant development.
Several potential risk factors for PPD have been identified, such as a history of depression before pregnancy, depression or anxiety during pregnancy and poor social support. Obesity at the beginning of pregnancy may also be a factor. PPD has been suggested to be a preface to a chronic depressive disorder. High pre-pregnancy BMI and excessive weight gain during pregnancy are associated with a significantly higher risk of GDB. Women with GDB are known to be at a higher risk of developing type 2 diabetes mellitus later in life.
The researchers set out to clarify the association between GDB and PPD. The study was conducted as part of the ongoing Kuopio Birth Cohort Study, which was initiated in Finland in 2012, collecting data from 10,000 mother and child pairs until the child reaches the age of 18. All women giving birth at the Kuopio University Hospital are invited to participate in the study. The study tested all participating women for GDB and PPD via clinical tests and surveys. In the whole study population, the prevalence rates of GDB and PPD were 14.1 percent and 10.3 percent respectively. Women with GDB had a higher prevalence of PPD. Women in the GDB group were also older and their BMI in the first trimester was higher than among women in the non-GDB group. Among women with GDB, the gestational age at delivery was lower than among those with no GDB.
Of the women with PPD, 40.9 per cent had third-trimester depressive symptomatology. In the whole sample, the prevalence of third-trimester depressive symptomatology was 9.5 percent – and of these women, 44.6 percent subsequently developed PPD.
Psychological factors may at least partly explain the observed association between GDB and PPD. The diagnosis of GDB may be considered as a stressful life event, which itself is an established risk factor for PPD.
Further studies should investigate whether women diagnosed with both GDB and PPD would benefit from closer follow-up and possible supportive interventions during pregnancy and the postpartum period to prevent further depressive symptoms. It would be beneficial to resolve whether the phycological burden related to the GDB diagnosis is a significant part of these mechanisms.
The association between gestational diabetes mellitus and postpartum depressive symptomatology: A prospective cohort study. Ruohomäki A, Toffol E, Upadhyaya S, Keski-Nisula L, Pekkanen J, Lampi J, Voutilainen S, Tuomainen TP, Heinonen S, Kumpulainen K, Pasanen M, Lehto SM. J Affect Disord (2018)