Pregnancy Outcome in Women with Gestational Diabetes - A Longitudinal Study of Changes in Demography and Treatment Modalities

Introduction Gestational diabetes is on the rise and demographics are changing in many countries due to increased migration. Simultaneously, the treatment of gestational diabetes in our clinic has shifted towards metformin with substantially less insulin treatment. The aim was to study the impact of these changes on metabolic control and pregnancy outcome by comparing women diagnosed with gestational diabetes during 2012-2013 and 2016-2017. Material and methods Our universal Oral Glucose Tolerance Test screening program for gestational diabetes diagnosed 199 women with singleton pregnancies during 2012-2013 and 203 during 2016-2017. Treatment and achieved metabolic control in the two different time periods were compared. Pregnancy outcome data related to gestational diabetes were retrieved from case notes and compared between the different time periods. Results When comparing results from 2016-2017 with 2012-2013 there was no difference in maternal weight or weight gain. There was a higher frequency of heredity (52.6 vs 35.4%; P = 0.001) and non-Scandinavian ethnicity (46.5 vs 33.8%; P = 0.011).The frequency of smoking during pregnancy was significantly lower (2.6 vs 7.7%; P = 0.023) There was an improved metabolic control as measured by median glucose in 2016-2017 compared with 2012-2013 (5.8 vs 6.2 mmol/L; P < 0.001). Insulin was less frequently used in 2016-2017 than in 2012-2013 (32.5 vs 44.7%; P = 0.012). There was a significant increase in the use of metformin (14.8 vs 0%; P < 0.001). There were no differences regarding the frequency of large-for-gestational-age infants (8.2% vs 7.3%; P = 0.762) or macrosomia (16.3 vs 15.1%; P = 0.745), median birthweight (3510 vs 3521; P = 0.879), frequency of cesarean section (28.1 vs 27.8%; P = 0.951) or Apgar scores at 10 minutes (10 [3-10] vs 10 [7-10]; P = 0.290). Conclusions In an increasing but changing population of gestational diabetes women in our region, with more hereditary and non-Scandinavian origins, but with fewer smokers, metabolic control has improved with maintained favorable pregnancy outcomes, with more frequent use of metformin and substantially less use of insulin treatment.