SCREENING FOR DIABETES IN THE FIRST TRIMESTER: WHY & HOW? Jillian Coolen, MD FRCSC DCPNS Spring Conference April 21, 2016
DISCLOSURE Site investigator for the CONCEPTT study funded by Juvenile Diabetes Research Foundation International
OBJECTIVES 1. To highlight why early screening and diagnosis is important 2. To present the evidence to inform an approach to early screening
BACKGROUND Prevalence of diabetes in reproductive aged women has increased - Increasing BMI - Advanced maternal age
NOVA SCOTIA: INCIDENCE OF DIABETES IN PREGNANCY % 7 6 5 4 3 2 1 0 Pre-existing GDM Total Source: Reproductive Care Program of Nova Scotia, Atlee Perinatal Database (2014)
NOVA SCOTIA: INCIDENCE OF GDM 7.0% 6.0% 5.0% 4.0% 3.0% 2.0% 1.0% 0.0% Source: Reproductive Care Program of Nova Scotia, Atlee Perinatal Database (2014)
GDM: BY MATERNAL AGE & PARITY 12% 2001/02 2002/03 2003/04 2004/05 2005/06 2006/07 2007/08 2008/09 2009/10 2010/11 2011/12 2012/13 2013/14 10% 8% 6% 4% 2% 0% <20 years 20-34 years > 34 years Nulliparous Parity 1+ Source: Reproductive Care Program of Nova Scotia, Atlee Perinatal Database (2014)
GDM: BY MATERNAL PREPREGNANCY BMI 25% 2001/02 2002/03 2003/04 2004/05 2005/06 2006/07 2007/08 2008/09 2009/10 2010/11 2011/12 2012/13 2013/14 20% 15% 10% 5% 0% < 20 20-24.99 25-29.99 30-34.99 35-39.99 40 Source: Reproductive Care Program of Nova Scotia, Atlee Perinatal Database (2014)
DIABETES IN PREGNANCY 13% Pre-existing 87% GDM - Includes Overt diabetes Undiagnosed type 2 diabetes
EARLY SCREENING CDA 2013 - Suggest screening before 24-28 weeks for: Women at risk for overt diabetes Women at high risk for GDM based on multiple risk factors - No specific test recommended
BENEFITS OF EARLY SCREENING & DIAGNOSIS 1. Improved pregnancy outcomes 2. Earlier referral for specialized services 3. Screening for diabetes related morbidity 4. Closer postpartum follow-up 5. GDM prevention?
1. IMPROVED PREGNANCY OUTCOMES Earlier diagnosis Earlier treatment Lower rates of adverse outcomes
2. EARLIER REFERRAL FOR SPECIALIZED SERVICES Earlier diagnosis Referral to FATC for EPR / Detailed US Earlier dx of congenital anomalies
3. SCREENING FOR DIABETES RELATED MORBIDITY Suspected Pre-existing diabetes Screen for diabetes related morbidity Retinopathy Nephropathy Associated with an increased risk for hypertensive disorders of pregnancy Autonomic Neuropathy Gastroparesis Urinary retention Hypoglycemic unawareness Orthostatic hypotension
4. CLOSER POSTPARTUM FOLLOW-UP 75-g OGTT 6 weeks to 6 months postpartum Poor compliance Vs. SMBG Continued hyperglycemia Earlier intervention Dietary & exercise counselling Weight management Oral hypoglycemics
5. GDM PREVENTION? Early screening Identified at increased risk for GDM Lifestyle counselling (ex: to reduce Gestational Weight Gain) Prevent diagnosis of GDM at 24-28 weeks
WHICH TEST & CRITERIA TO USE? 2 strategies: 1. Non-pregnancy recommended screening tests fasting plasma glucose (FPG) or glycated hemoglobin (A1C) 2. 24-28 week GDM screening / diagnostic tests 50-g GCT and/or 75-g OGTT using GDM criteria
WHICH TEST & CRITERIA TO USE? Flawed! 1. Non-pregnancy recommended screening tests fasting plasma glucose (FPG) or glycated hemoglobin (A1C) Does not take into account that both drop early in pregnancy underdiagnose women with preexisting diabetes
WHICH TEST & CRITERIA TO USE? Flawed! 2. 24-28 week GDM screening / diagnostic tests 50-g GCT and/or 75-g OGTT using GDM criteria Not validated for use in the first trimester
THE EVIDENCE
PREDICTION OF ADVERSE OBSTETRICAL OUTCOMES Riskin-Mashiah et al, 2009-6129 women, first trimester FPG < 105 mg/dl - Linear relationship between FPG results and macrosomia, c/section rates & second trimester dx with GDM
PREDICTION OF ADVERSE OBSTETRICAL OUTCOMES Hughes et al, 2014-16,122 women, first trimester A1C - A1C 5.9-6.4% associated with higher rates of Major congenital anomalies (RR 2.67, CI 1.28-5.53) Preeclampsia (RR 2.42, CI 1.34-4.38) Shoulder dystocia (RR 2.47, CI 1.05-5.85) Perinatal death (RR 3.96, CI 1.54-10.16)
PREDICTION OF GDM Hughes et al, 2014-16,122 women, first trimester A1C 5.9% Sensitivity = 100% Specificity = 97.4% PPV = 18.8% NPV = 100%
PREDICTION OF POSTPARTUM DYSGLYCEMIA Granada et al, 2014 - A1C 5.9% in the first trimester PPV = 47% NPV = 96%
LL PREGNANT WOMEN AT 24 TO 28 WEEKS 1ST TRIMESTER EARLY SCREENING ractice Guidelines Expert Committee. Canadian Diabetes Association 2013 Clinical Practice Guidelines for the Prevention and al of Diabetes. 2013;37 (Suppl 1):S1-212. CURRENT SCREENING ALGORITHMS FOR GDM Pregnancy and Diabetes Guidelines Manual APPENDIX A: SCREENING FOR GESTATIONAL DIABETES (GDM) Screening for GDM Screen pregnant women at HIGH RISK for GDM (see Table 1) as early in the pregnancy as feasible (random 50 g; 1-hour GCT) Venous plasma glucose (VPG) < 7.8 mm If GDM is strongly suspected, a 75-g OGTT* can be performed without initial GCT (e.g., multiple risk factors) VPG 7.8 mm to 11.0 mm SCREEN ALL PREGNANT women for GDM at 24 to 28 weeks gestation (random 50 g; 1-hour GCT) Administer 75 g, 2-hour OGTT* (Interpret as below) 1-hour PG < 7.8 mm 1-hour VPG 7.8 mm to 11.0 mm 1-hour VPG 11.1 mm** NO GDM GDM Administer 75 g, 2-hour OGTT* If normal, repeat 75 g OGTT* at 24 to 28 weeks (Do not repeat 50 g screen) If fasting VPG 5.3 mm, test should not be continued, as GDM is present Fasting VPG 5.3 mm 1-hour 10.6 mm 2-hour 9.0 mm NO ABNORMAL VALUES, NO GDM IF ONE VALUE ABNORMAL, GDM IS PRESENT CDA 2013 DCPNS 2014 Meal plan; physical activity; Self-monitoring of blood glucose (SMBG)
SUGGESTED ALGORITHM
THANK YOU QUESTIONS? Autumn 2015, Diabetes Communicator
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