The changing face of gestational diabetes: the effect of the shift from risk factor-based to comprehensive screening

Abstract

Objective: To evaluate the effect of the change in the gestational diabetes (GDM) screening policy from risk-factor based to comprehensive screening on the prevalence and type of GDM and characteristics of GDM pregnancies. Design: Population-based register study in Finland. Subjects were GDM women who gave birth before (2006, nZ5185) and after (2010, nZ6683) the policy change. All the other women in those years without pre-pregnancy diabetes acted as controls (51 759 and 52 398 respectively). Methods: GDM women with singleton pregnancy were identified through The Finnish Medical Birth Register by abnormal oral glucose tolerance test or initiation of insulin. Main outcome measures were prevalence of GDM (total and insulin/ diet-treated), and caesarean section rate. Results: The proportion of screened mothers increased from 27.5 to 51.3% and the total prevalence of GDM from 9.1 to 11.3%. This increase consisted mainly of diet-treated mothers, while the number and proportion of insulin-treated mothers decreased (21.8% vs13.3%, P!0.001). The proportion of primiparous women increased (34.5-39.4%, P!0.0001) and mean pre-pregnancy BMI decreased (28.6-28.2, P!0.001). The overall caesarean section rate remained the same but increased among women with .1%) adjusted odds ratios being 1.22 (95% CI 1.14, 1.31) during comprehensive and 1.10 (95% CI 1.02, 1.19) during risk factor-based screening. Conclusions: The shift to comprehensive screening led to a significant increase in women with GDM, who were more often primiparous and had a lower BMI. Comprehensive screening did not perform better in diagnosing women needing insulin treatment.

Towards national comprehensive gestational diabetes screening – consequences for neonatal outcome and care

“…We showed previously that the introduction of a large‐scale screening policy for gestational diabetes led to a significant increase in the proportion of women with GDM, who mainly had a mild form of the disease . In the present study, we further found that in newborns, screening policy change led to decreased mean birthweight and macrosomia rates, but the prevalence of neonatal hypoglycemia increased in both diet‐ and insulin‐treated mothers.…”

“…The need for care on a neonatal ward did not grow to the same degree as the prevalence of GDM, which may be due to the increased proportion of mild forms of disease. The amount of insulin‐treated women with GDM decreased significantly when the new uniform guidelines standardized both screening policy and cut‐off levels to insulin treatment . However, the effect of this change to the increased incidence of neonatal hypoglycemia is unclear.…”

“…The previously used risk‐factor‐based screening was replaced with nearly comprehensive screening, excluding only the estimated approximately 20% of women at very low risk of GDM. The shift to wide‐scale screening led to a significant increase in women with mainly diet‐treated GDM, who were more often primiparous and had a lower body mass index (BMI) . Our aim was to evaluate how this change of policy affected the perinatal outcome and the need for care on a neonatal ward.…”

New guidelines for screening, diagnosing, and treating gestational diabetes – evaluation of maternal and neonatal outcomes in Finland from 2006 to 2012

“…The proportion requiring insulin treatment remained unchanged in our GDM study population. In a previous population-based Finnish study, the proportion of insulin-treated women with GDM was reduced from 21.8% in 2006 to 13.3% in 2010 (17), hence approaching the prevalence in our study population. According to our results, the comprehensive screening method was unable to detect more women with a severe form of GDM who require insulin treatment.…”

“…This study included universal screening . However, when comparing the shift from risk‐based to comprehensive screening in a Finnish study, the prevalence of GDM increased, but the population‐based study was unable to find evidence regarding the optimal screening method . The National Institute of Health and Care Excellence guidelines published in 2015 recommend risk‐based screening if a woman has one or several of the following risk factors: body mass index (BMI) >30 kg/m 2 , a previous macrosomic baby, a family history of diabetes, or a minority ethnic family of origin with a high prevalence of diabetes.…”