Incidence of gestational diabetes rises in England

More than one in eight births in England was affected by gestational diabetes (GDM) by the end of 2022, after diagnoses rose by 60% in just five years, according to a major study published in BMJ Medicine. The research also reported profound inequalities in incidence and pregnancy outcomes by ethnic group and socioeconomic status.

Gestational diabetes is the most common complication of pregnancy and is associated with adverse obstetric outcomes, including infants born either larger or smaller than expected for gestational age, preterm birth and intervention during delivery. It is also associated with an increased risk of long-term cardiometabolic disorders for mothers and their offspring.

Estimates of the incidence of GDM in the UK have previously been determined through clinical audit but have varied greatly across regions, limiting their usefulness in planning maternity services. To address this gap in understanding, researchers from the University of Edinburgh and King’s College London examined data from all NHS hospital births in England from 1 January 2018 to 31 December 2022. Over 2.3 million mothers and around 2.8 million births across 184 hospitals were included in the analysis.

The investigators identified 274,500 pregnancies with a diagnosis of GDM, representing 9.9% of all births during the study period. Although the total number of births fell, both the number and proportion of pregnancies affected by GDM increased. Prevalence rose from 7.5% in January 2018 to more than 12% by the end of 2022, a relative increase of 60% over five years.

Rates of GDM diagnoses increased for all socioeconomic and ethnic subgroups. In every year studied, GDM was most common among those experiencing the highest level of socioeconomic deprivation and those identifying as non-white; these groups were also at higher risk of adverse obstetric outcomes. The greatest absolute increase in GDM occurred in women from black and Asian ethnic groups, while the largest relative increase occurred among white individuals.

Rising maternal age, increasing rates of obesity and improved data capture each contributed to the increase in recorded GDM prevalence. Changes to screening methodology introduced during the Covid-19 pandemic did not meaningfully affect the overall diagnostic trends. The high rates of GDM and the inequalities revealed in the study underline the urgent need for strategies to improve maternity and follow-up care. This must include preventative measures to reduce the risk of future type 2 diabetes and cardiovascular disease.

The original article can be read here.