2/13/2018 Update on Gestational Diabetes Lorie M. Harper, MD, MSCI - PDF document

2/13/2018 Update on Gestational Diabetes Lorie M. Harper, MD, MSCI Department of Obstetrics & Gynecology Division of Maternal-Fetal Medicine 2/18/2018 Disclosure  I have no financial conflicts of interest. Objectives  Identify appropriate screening strategies for gestational diabetes  Describe the risks associated with GDM and benefits of treatment  Describe the management of GDM, during & after pregnancy 1

2/13/2018 Outline  What is GDM?  What are the consequences of GDM?  Are there benefits to treating GDM?  How should I screen for GDM?  When should I screen for GDM?  How should I manage GDM? What is GDM? Carbohydrate intolerance of variable severity with onset or first recognition during pregnancy GDM Complications  Maternal  Neonatal  Hypertensive disorders  Stillbirth of pregnancy  Macrosomia  Increased risk of  Shoulder dystocia cesarean  Birth trauma  Hypoglycemia  Hyperbilirubinemia  Obesity  Diabetes 2

2/13/2018 Harms of Diagnosing/Treating GDM  More clinic visits  Time away from work  “Loss of control”  “Medicalization” of pregnancy  Increased induction  Iatrogenic cesarean  Iatrogenic NICU admissions Benefits of Treating GDM  Two randomized controlled trials:  ACHOIS – Crowther et al, NEJM 2005  MFMU – Landon et al, NEJM 2009 ACHOIS  Diagnosis of GDM:  Two-step screening (50g followed by 75g)  Normal fasting  2-hour <198 mg/dL =MILD GDM  Randomized  Blinded 3

2/13/2018 ACHOIS Treatment Routine Care Relative p (n=506) (n=524) Risk Any Serious 0.32 Perinatal 7 (1%) 23 (4%) 0.004 (0.14-0.73) Complication Death 0 5 (1%) -- 0.06 0.45 Shoulder Dystocia 7 (1%) 16 (3%) 0.07 (0.19-1.09) Admission to 1.15 357 (71%) 321 (61%) 0.002 Nursery (1.05-1.26) 0.62 LGA 68 (13%) 115 (22%) <0.001 (0.47-0.81) 0.47 Macrosomia 49 (10%) 110 (21%) <0.001 (0.34-0.64) 1.42 Hypoglycemia 35 (7%) 27 (5%) 0.16 (0.87-2.32) ACHOIS Treatment Routine Care Relative Risk p (n=506) (n=524) Induction of 1.31 189 (39%) 150 (29%) 0.002 Labor (1.10-1.56) 0.96 Cesarean 152 (31%) 164 (32%) 0.70 (0.80-1.16) 0.70 Preeclampsia 58 (12%) 93 (18%) 0.02 (0.51-0.95) MFMU  Diagnosis of GDM  Two step screening (50g followed by 100g)  Normal fasting (<95 mg/dL)  At least 2 abnormal: 1-hour >180, 2-hour >155, 3- hour >140 =MILD GDM  Randomized  Blinded 4

2/13/2018 MFMU Treatment Control Relative p (n=485) (n=473) Risk Gestational Age at 39.0 ± 1.8 38.9 ± 1.8 0.87 Birth 0.87 Composite 149 (32.4%) 163 (37.0%) 0.14 (0.72-1.07) 1.06 Hypoglycemia 62 (16.3%) 55 (15.4%) 0.75 (0.73-1.53) 0.74 Hyperbilirubinemia 43 (9.6%) 54 (12.9%) 0.12 (0.49-1.12) 0.78 C-peptide 75 (17.7%) 92 (22.8%) 0.07 (0.57-1.05) Death 0 0 0.48 Birth Trauma 3 (0.6%) 6 (1.3%) 0.33 (0.10-2.20) MFMU Treatment Control Relative p (n=485) (n=473) Risk < Birth Weight 3302 ± 502 3408 ± 589 0.001 0.41 < Macrosomia 28 (5.9%) 65 (14.3%) (0.26-0.66) 0.001 0.49 < LGA 34 (7.1%) 66 (14.5%) (0.32-0.76) 0.001 Fat Mass 427 ± 198 464 ± 222 0.003 0.37 Shoulder Dystocia 7 (1.5%) 18 (4.0%) 0.02 (0.14-0.97) MFMU Treatment Control Relative p (n=485) (n=473) Risk 1.02 Induction of Labor 130 (27.3%) 122 (26.8%) 0.86 (0.81-1.29) 0.79 Cesarean Delivery 128 (26.9%) 154 (33.8%) 0.02 (0.64-0.99) Preeclampsia or 0.63 Gestational 41 (8.6%) 62 (13.6%) 0.01 (0.42-0.96) Hypertension 5

2/13/2018 Benefits of Treating GDM ACHOIS MFMU Reduced Serious MAYBE YES Perinatal Morbidity? (shoulder dystocia) Reduced Macrosomia, YES YES LGA, Birth Weight? Reduced Neonatal NO NO Hypoglycemia? Reduced Neonatal Fat -- YES Mass? Induction of Labor INCREASED No Difference Reduced Cesarean? NO YES Reduced Preeclampsia? YES YES Screening for GDM Old versus “New” Screening for GDM  Two Step  One Step (IADPSG)  50-g load, 1-hour  75-g load, 2-hour  100-g load, 3-hour  Carpenter-Coustan  National Diabetes Data Group 6

2/13/2018 Diagnostic Thresholds Carpenter NDDG Coustan Fasting 95 105 One Hour 180 190 Two Hour 155 165 Three Hour 140 145 Requires: 2 abnormal values Diagnostic Thresholds Carpenter NDDG IADPSG Coustan Fasting 95 105 92 One Hour 180 190 180 Two Hour 155 165 153 Three Hour 140 145 -- Requires: 2 abnormal values 1 abnormal value Where did the new IADPSG criteria come from? Hyperglycemia & Adverse Pregnancy Outcomes  Prospective observational study  75-g glucose test between 24-32 weeks  Primary outcomes:  Birth weight >90 th percentile  Primary cesarean  Neonatal hypoglycemia  Cord blood C-peptide >90 th percentile 7

2/13/2018 HAPO: What we hoped to find HAPO: What we did find The HAPO PO St Study Cooperative Research Group. N En Engl J Med 2008;358:1991-2002. IADPSG Odds Ratio for Primary Outcome Prevalence of GDM 1.5 25% 1.75 16.1% 2.0 8.8% Glucose Cumulative Glucose Measure Concentration % Above Threshold (mg/dL) Fasting 92 8.3% 1-Hour 180 14.0% 2-Hour 153 16.1% IADPSG, Diabetes Care 2010; 33(3): 676-682 8

2/13/2018 Two Step versus One Step  Two Step  One Step  Not based on perinatal  Based on perinatal outcomes outcomes Two Step versus One Step  Two Step  One Step  Not based on perinatal  Based on perinatal outcomes outcomes  4-8% prevalence of  16% prevalence of GDM GDM Implications of Increased Prevalence  Increased prenatal visits - >1 million  Increased patient education visits – 450,000  Increased antenatal testing – 1 million 9

2/13/2018 Two Step versus One Step  Two Step  One Step  Not based on perinatal  Based on perinatal outcomes outcomes  4-8% prevalence of  16% prevalence of GDM GDM  Evidence of treatment  Treatment benefit not benefit examined Two Step versus One Step  Two Step  One Step  Not based on perinatal  Based on perinatal outcomes outcomes  4-8% prevalence of  16% prevalence of GDM GDM  Evidence of treatment  Treatment benefit not benefit examined  Screening step without  All women must do fasting fasting test Benefits of One Step Testing  36% reduction in lab workload  Scheduling issues for all women to come in fasting  Overall increase in cost (42%) 10

2/13/2018 Two Step versus One Step  Two Step  One Step  Not based on perinatal  Based on perinatal outcomes outcomes  4-8% prevalence of  16% prevalence of GDM GDM  Evidence of treatment  Treatment benefit not benefit examined  Screening step without  All women must do fasting fasting test  Two visits  One visit Benefits of One Step Testing  No loss to follow up after an elevated one hour  No delay in diagnosis Delay in Diagnosis Created by 2-Step ≤7 Days 8-14 Days >14 Days p n=306 n=143 n=100 Primary 23.5% 25.4% 13.0% 0.12 Cesarean Preeclampsia 10.8% 8.4% 7.0% 0.22 Preterm Birth 16.3% 14.7% 15.0% 0.68 Birth Weight 3328 ± 649 3283 ± 575 3375 ± 647 0.53 Macrosomia 12.4% 9.1% 12.0% 0.68 Birth Injury 2.0% 1.4% 4.1% 0.63 Siegel et al, Am J Perinatol. 2017; 34(6): 557-562 11

2/13/2018 Two Step versus One Step  Two Step  One Step  Not based on perinatal  Based on perinatal outcomes outcomes  4-8% prevalence of  16% prevalence of GDM GDM  Evidence of treatment  Treatment benefit not benefit examined  Screening step without  All women must do fasting fasting test  Two visits  One visit Two Step Testing: Which cutoffs should we use? One Hour Glucose Challenge Test  50-gram glucose load  Blood draw at 1-hour  No need to fast  Cut off options: Higher false positive rate, lower positive predictive  130 value, more 3-hour GTTs performed  135 Lower false positive rate, improved positive  140 predictive value, fewer 3-hour GTTs performed 12

2/13/2018 Carpenter-Coustan vs NDDG Carpenter Coustan NDDG Fasting 95 105 One Hour 180 190 Two Hour 155 165 Three Hour 140 145 Requires: 2 abnormal values  Carpenter-Coustan criteria diagnoses 50% more women with GDM  Carpenter Coustan used in the MFMU trial Carpenter-Coustan vs NDDG Carpenter Coustan NDDG P (n=389) (n=542) Treated Usual Care Treated Usual Care Interaction (n=196) (n=193) (n=280) (n=262) PIH 8.2% 14.0% 8.9% 13.4% 0.73 Shoulder 1.8% 5.7% 1.0% 1.6% 0.43 Dystocia Cesarean 27.9% 30.2% 25.5% 38.9% 0.08 Delivery LGA 6.1% 15.7% 8.7% 13.0% 0.17 • Direction of effect favors treatment regardless of which diagnostic criteria used used Harper et al for MFMU, Obstet Gynecol, 2016; 127(5) Diagnostic Criteria Summary  NICHD, ACOG endorse two step screening  (although one step is acceptable)  No specific two step screening cutoffs endorsed although there is evidence of treatment effect using Carpenter Coustan criteria 13

2/13/2018 Timing of Screening When to Screen  Routine Screening:  24-28 weeks  Balance between:  Increasing insulin resistance  Time for treatment Early Screening  Goals:  Detect undiagnosed pre-gestational diabetes  Detect early onset GDM  Improve perinatal outcomes associated with DM/GDM:  PIH, shoulder dystocia, LGA, cesarean 14