Abstract
Objectives
This guideline reviews the evidence relating to the diagnosis and obstetrical management
of diabetes in pregnancy.
Outcomes
The outcomes evaluated were short and long-term maternal outcomes including pre-eclampsia,
Caesarean section, future diabetes and other cardiovascular complications; and fetal
outcomes including congenital anomalies, stillbirth, macrosomia, birth trauma, hypoglycemia
and long-term effects.
Evidence
Published literature was retrieved through searches of PubMed and The Cochrane Library
using appropriate controlled vocabulary (MeSH terms “diabetes” and “pregnancy”). Where
appropriate, results were restricted to systematic reviews, randomized control trials/controlled
clinical trials, and observational studies. There were no date limits but results
were limited to English or French language materials.
Values
The quality of evidence was rated using the criteria described in the Report of the
Canadian Task Force on Preventive Health Care.
Summary Statements
- 1The adverse outcomes associated with diabetes in pregnancy are substantially associated with hyperglycemia as well as the co-existing metabolic environment. Women with pre-existing diabetes should receive preconception care to optimize blood sugar control and other co-morbidities. Outcomes for the fetus/neonate and the mother in both pre-gestational diabetes mellitus and gestational diabetes mellitus pregnancies are improved by multidisciplinary management whose goal is achieving optimal blood sugar control and appropriate fetal surveillance (II-2).
- 2Retrospective studies indicate that women with pre-gestational diabetes mellitus have an increased risk of stillbirth before 40 weeks of gestation when compared with the general obstetrical population. Similarly, large recent cohort and simulation studies of women with gestational diabetes mellitus pregnancies also indicate a higher risk of stillbirth between 36-39 weeks gestation (II-2).
- 3Women with gestational diabetes mellitus have a higher risk of pre-eclampsia, shoulder dystocia, Caesarean section and large for gestational age infants (II-2).
- 4Treatment of women with gestational diabetes mellitus and optimization of glycemic control reduces the risk of pre-eclampsia, shoulder dystocia, and large for gestational age infants (I).
- 5The occurrence of gestational diabetes mellitus increases the risk of developing type 2 diabetes in the future for the mother (II-2).
Recommendations
- 1The “preferred screening and diagnostic 2-step” approach for gestational diabetes mellitus from Diabetes Canada's 2018 guidelines is endorsed. All pregnant women should be offered screening between 24-28 weeks using a standardized non-fasting 50-g glucose challenge screening test (GCT) with plasma glucose (PG) measured 1 hour later (III-B).
- 1.1If the value is <7.8 mmol/L, no further testing is required.
- 1.2If the value of the GCT is 7.8–11.0, a 2-hour 75-g oral glucose tolerance test with fasting PG (FPG), 1-hour PG, 2-hour PG should be performed.Gestational diabetes mellitus is diagnosed if 1 value is met or exceeded:
- iFPG ≥5.3 mmol/L
- ii1-h PG ≥10.6 mmol/L
- iii2-h PG ≥9.0 mmol/L
- i
- 1.3If the value of the GCT is ≥11.1 mmol/L, gestational diabetes mellitus is diagnosed
- 1.1
- 2The “alternative 1-step diagnostic” approach from Diabetes Canada's 2018 guidelines is acceptable. In this strategy pregnant women should be offered testing between 24-28 weeks using a standardized 2-hour 75-g oral glucose tolerance test with fasting plasma glucose (FPG), 1-hour plasma glucose (PG), 2-hour PG (III-B).Gestational diabetes mellitus is diagnosed if 1 value is met or exceeded:
- iFPG ≥5.1 mmol/L
- ii1-h PG ≥10.0 mmol/L
- iii2-h PG ≥8.5 mmol/L
It is recognized that the use of different diagnostic thresholds for the “preferred” and “alternate” strategies could cause confusion in certain settings. Despite this the committee has identified the importance of remaining aligned with the current Diabetes Canada guidelines as being a priority. It is thus recommended that each care centre strategically align with one of the two strategies and implement protocols to ensure consistent and uniform reporting of test results. - i
- 3If there is a high risk of gestational diabetes mellitus based on multiple risk factors, screening or testing should be offered during the first half of the pregnancy and repeated at 24-28 weeks gestation if initially normal. If for any reason it was missed or if there is a clinical suspicion of later onset gestational diabetes, a screening or diagnostic test should be performed (II-2B).
- 4Women with pre-existing or gestational diabetes mellitus should be provided with care by a multidisciplinary team aimed at attaining and then maintaining euglycemia (II-2B).
- 5For patients with pre-gestational diabetes mellitus or gestational diabetes mellitus, starting at 28 weeks as a baseline, with subsequent serial assessment of fetal growth every 3-4 weeks is suggested to assess the effect of maternal glycemic control on fetal growth rate and amniotic fluid volume (II-2B).
- 6Initiation of weekly assessment of fetal well-being at 36 weeks is recommended in pre-gestational diabetes mellitus and in gestational diabetes mellitus. It is also reasonable to consider weekly fetal assessment for women with diet controlled gestational diabetes mellitus beginning at 36 weeks. Acceptable methods of assessment of fetal well-being near term can include the non-stress test, non-stress test + amniotic fluid index, biophysical profile or a combination of the above (III-A).
- 7If co-morbid factors are present such as obesity, evidence of suboptimal glycemic control, large for gestational age (>90%), previous stillbirth, hypertension or small for gestational age (<10%) are present, earlier onset and/or more frequent fetal health surveillance is recommended. In specific cases where fetal growth restriction is suspected, the addition of umbilical artery and fetal middle cerebral artery Doppler assessment may be helpful (II-2A).
- 8Pregnant women with gestational diabetes mellitus or with pre-gestational diabetes mellitus should be offered induction between 38-40 weeks of gestation depending on their glycemic control and other co-morbidity factors (II2-B).
- 9Antenatal corticosteroid therapy should be administered to women with insulin-treated gestational diabetes mellitus and pregestational diabetic women at the same dosage, according to the same indications, and in the same gestational age range as that recommended for non-diabetic women (Skoll A, et al. No. 364-Antenatal Corticosteroid Therapy for Improving Neonatal Outcomes. J Obstet Gynaecol Can 2018;40:1219-39). When administered to women with preexisting or poorly controlled diabetes, close maternal glycemic surveillance is recommended (III-B). Following the first dose of betamethasone, the following insulin adjustments are recommended as per Diabetes Canada guidelines (Diabetes Canada Clinical Practice Guidelines Expert C, et al. Diabetes and Pregnancy. Can J Diabetes 2018;42 Suppl 1:S255-S82):
- •Day 1: Increase the night insulin dose by 25%
- •Days 2 and 3: Increase all insulin doses by 40%
- •Day 4: Increase all insulin doses by 20%
- •Day 5: Increase all insulin doses by 10% to 20%
- •Days 6 and 7: Gradually taper insulin doses to pre-betamethasone doses
- •
- 10If not previously done, in women with threatened preterm labour requiring betamethasone, a screening and diagnostic test for gestational diabetes mellitus should be performed either before or at least 7 days after the administration of betamethasone (III-B).
- 11Women with GDM should be offered testing with a 75-g oral glucose tolerance test between 6 weeks and 6 months postpartum to detect prediabetes and diabetes (Diabetes Canada Clinical Practice Guidelines Expert C, et al. Diabetes and Pregnancy. Can J Diabetes 2018;42 Suppl 1:S255-S82) (II-2A).
-
11.1 Normal
- iFasting plasma glucose (FPG) <6.1 mmol/L
- ii2h <7.8 mmol/L
- iiiHbA1C <6.0%
- i
-
11.2 Pre-diabetic
- iFPG 6.1-6.9 mmol/L or
- ii2h plasma glucose (PG) 7.8-11.0 mmol/L or
- iiiHbA1C 6.0-6.4%
- i
-
11.3 Type 2 Diabetes mellitus
- iFPG ≥ 7.0 mmol/L
- iiRandom PG or 2h PG ≥11.1 mmol/L
- iiiHbA1C ≥6.5%
- i
-
- 12Breastfeeding is strongly recommended after delivery for all women with pre-gestational diabetes mellitus or gestational diabetes mellitus (II-2A).
Key Words
Abbreviations:
ACOG (American College of Obstetricians and Gynecologists), FPG (fasting plasma glucose), GCT (glucose challenge screening test), GDM (gestational diabetes mellitus), HAPO (Hyperglycemia and Adverse Pregnancy Outcome study), IADPSG (International Association of Diabetes and Pregnancy Study Groups), NND (number needed to deliver), OGTT (oral glucose tolerance test), PG (plasma glucose), PGDM (pre-gestational diabetes mellitus), RCT (randomized controlled trial), RPG (random plasma glucose), SMBG (self-monitored blood glucose)To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Journal of Obstetrics and Gynaecology CanadaAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Trends in incidence of diabetes in pregnancy and serious perinatal outcomes: a large, population-based study in Ontario, Canada, 1996-2010.Diabetes Care. 2014; 37: 1590-1596
- Maternal and neonatal outcomes and time trends of gestational diabetes mellitus in Sweden from 1991 to 2003.Diabet Med. 2010; 27: 436-441
- Effect of treatment of gestational diabetes mellitus on pregnancy outcomes.N Engl J Med. 2005; 352: 2477-2486
- A multicenter, randomized trial of treatment for mild gestational diabetes.N Engl J Med. 2009; 361: 1339-1348
- Diet-treated gestational diabetes mellitus: comparison of early vs routine diagnosis.Am J Obstet Gynecol. 2008; 198 (e1-6): 287
- Impaired glucose tolerance of pregnancy is a heterogeneous metabolic disorder as defined by the glycemic response to the oral glucose tolerance test.Diabetes Care. 2006; 29: 57-62
- Diabetes and Pregnancy.Can J Diabetes. 2018; 42 Suppl 1 (Erratum in: Can J Diabetes. 2018 Jun;42(3):337): S255-S282
- Immortal time bias in the study of stillbirth risk factors: the example of gestational diabetes.Epidemiology. 2013; 24: 787-790
- Decreased perinatal mortality among women with diet-controlled gestational diabetes mellitus.Int J Gynaecol Obstet. 2009; 104: 199-202
- Risk factors for intrauterine fetal death (1988-2009).J Matern Fetal Neonatal Med. 2011; 24: 1079-1083
- Pregnancy outcomes in diabetes subtypes: how do they compare? A province-based study of Ontario, 2005-2006.J Obstet Gynaecol Can. 2009; 31: 487-496
- Gestational age-specific severe maternal morbidity associated with labor induction.Am J Obstet Gynecol. 2013; 209 (e1-8): 209
- The risk of stillbirth and infant death stratified by gestational age in women with gestational diabetes.Am J Obstet Gynecol. 2012; 206 (e1-7): 309
- What is the optimal gestational age for women with gestational diabetes type A1 to deliver?.Am J Obstet Gynecol. 2014; 211 (e1-6): 418
- The risk of stillbirth and infant death by each additional week of expectant management stratified by maternal age.Am J Obstet Gynecol. 2013; 209 (e1-7): 375
- The impact of the active management of risk in pregnancy at term on birth outcomes: a randomized clinical trial.Am J Obstet Gynecol. 2008; 198 (e1-15): 511
- Stillbirth in diabetic pregnancies.Best Pract Res Clin Obstet Gynaecol. 2011; 25: 105-111
- Uses and abuses of screening tests.Lancet. 2002; 359: 881-884
- Screening for gestational diabetes mellitus: a systematic review for the U.S. Preventive Services Task Force.Ann Intern Med. 2008; 148: 766-775
- Attitudes and practices of healthcare providers regarding gestational diabetes: results of a survey conducted at the 2010 meeting of the International Association of Diabetes in Pregnancy Study Group (IADPSG).Diabet Med. 2011; 28: 976-986
- Impact of increasing carbohydrate intolerance on maternal-fetal outcomes in 3637 women without gestational diabetes. The Toronto Tri-Hospital Gestational Diabetes Project.Am J Obstet Gynecol. 1995; 173: 146-156
- Hyperglycemia and adverse pregnancy outcomes.N Engl J Med. 2008; 358: 1991-2002
- Standards of medical care in diabetes–2012.Diabetes Care. 2012; 35: S11
- Diagnosis and classification of diabetes mellitus.Diabetes care. 2014; 37: S81
- Practice bulletin no. 137: gestational diabetes mellitus.Obstet Gynecol. 2013; 122: 406-416
- Screening for gestational diabetes mellitus.J Obstet Gynaecol Can. 2002; 24: 894-912
- Does insulin secretion in patients with one abnormal glucose tolerance test value mimic gestational diabetes mellitus?.Am J Obstet Gynecol. 2002; 186: 204-209
- Gestational diabetes mellitus.Obstet Gynecol. 2011; 118: 1379-1393
- The relationship between maternal glycemia and perinatal outcome.Obstet Gynecol. 2011; 117: 218-224
- The significance of one abnormal glucose tolerance test value on adverse outcome in pregnancy.Am J Obstet Gynecol. 1987; 157: 758-763
Nankervis A, McIntyre HD, Moses R, et al., Australasian Diabetes in Pregnancy Society. ADIPS Consensus Guidelines for the Testing and Diagnosis of Gestational Diabetes Mellitus in Australia. Australasian Diabetes in Pregnancy Society; 2014. Available at: http://adips.org/downloads/ADIPSConsensusGuidelinesGDM-03.05.13VersionACCEPTEDFINAL.pdf. Accessed on March 22, 2019.
World Health Organization. Diagnostic criteria and classification of hyperglycaemia first detected in pregnancy. 2013.
- Gestational diabetes mellitus: to screen or not to screen?: Is this really still a question?.Diabetes Care. 2013; 36: 2877-2878
- Screening or diagnostic: markedly elevated glucose loading test and perinatal outcomes.J Matern Fetal Neonatal Med. 2006; 19: 729-734
- Carpenter-Coustan criteria compared with the national diabetes data group thresholds for gestational diabetes mellitus.Obstet Gynecol. 2009; 114: 326-332
- Effect of new criteria on the diagnosis of gestational diabetes in women submitted to gastric bypass.Surg Obes Relat Dis. 2014; 10: 1041-1046
- An association between hyperinsulinemia and hypertension during the third trimester of pregnancy.Am J Obstet Gynecol. 1988; 159: 446-450
- Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy: executive summary.J Obstet Gynaecol Can. 2014; 36: 416-441
- Glucose tolerance test: degree of glucose abnormality correlates with neonatal outcome.Obstet Gynecol. 1993; 81: 344-348
- Fetal surveillance in pregnancies complicated by insulin-dependent diabetes mellitus.Am J Obstet Gynecol. 1992; 167: 617-621
- Abnormal growth patterns in diabetes in pregnancy: a longitudinal study.Isr J Med Sci. 1991; 27: 516-523
- Associated factors in 1611 cases of brachial plexus injury.Obstet Gynecol. 1999; 93: 536-540
- Shoulder dystocia and associated risk factors with macrosomic infants born in California.Am J Obstet Gynecol. 1998; 179: 476-480
- Birth weight and fetal death in the United States: the effect of maternal diabetes during pregnancy.Am J Obstet Gynecol. 2002; 187: 922-926
- Macrosomic births in the united states: determinants, outcomes, and proposed grades of risk.Am J Obstet Gynecol. 2003; 188: 1372-1378
- Maternal and infant complications in high and normal weight infants by method of delivery.Obstet Gynecol. 1998; 92: 507-513
- Factors associated with cesarean delivery in nulliparous women with type 1 diabetes.Obstet Gynecol. 2010; 115: 1014-1020
- Cesarean delivery in relation to birth weight and gestational glucose tolerance: pathophysiology or practice style? Toronto Trihospital Gestational Diabetes Investigators.JAMA. 1996; 275: 1165-1170
- Delivery timing and cesarean delivery risk in women with mild gestational diabetes mellitus.Am J Obstet Gynecol. 2014; 211 (e1-7): 244
- A randomized trial evaluating a predominantly fetal growth-based strategy to guide management of gestational diabetes in Caucasian women.Diabetes Care. 2004; 27: 297-302
- Flexible treatment of gestational diabetes modulated on ultrasound evaluation of intrauterine growth: a controlled randomized clinical trial.Diabetes Metab. 2004; 30: 237-244
- Modified therapy for gestational diabetes using high-risk and low-risk fetal abdominal circumference growth to select strict versus relaxed maternal glycemic targets.Diabetes Care. 2007; 30 Suppl 2: S200-S205
- Glycosylated hemoglobin level in the second trimester predicts birth weight and amniotic fluid volume in non-diabetic pregnancies with abnormal screening test.J Matern Fetal Neonatal Med. 2010; 23: 1193-1199
- Fetal health surveillance: antepartum and intrapartum consensus guideline.J Obstet Gynaecol Can. 2007; 29: S3-56
- Fetal surveillance in pregnancy complicated by diabetes mellitus: is it necessary?.J Matern Fetal Neonatal Med. 2002; 12: 413-416
- Antepartum fetal surveillance and timing of delivery in the pregnancy complicated by diabetes mellitus.Clin Obstet Gynecol. 2007; 50: 1007-1013
- Biophysical profile scoring in the management of the diabetic pregnancy.Obstet Gynecol. 1988; 72: 841-846
- Fetal assessment based on the fetal biophysical profile score: relationship of last BPS result to subsequent cerebral palsy.J Gynecol Obstet Biol Reprod (Paris). 1997; 26: 720-729
- Fetal assessment based on fetal biophysical profile scoring. VIII. The incidence of cerebral palsy in tested and untested perinates.Am J Obstet Gynecol. 1998; 178: 696-706
- Sonographic fetal weight estimation: which model should be used?.J Ultrasound Med. 2009; 28: 617-629
- Sonographic prediction of fetal macrosomia: the consequences of false diagnosis.J Ultrasound Med. 2010; 29: 225-230
- Prediction of fetal macrosomia: effect of sonographic fetal weight-estimation model and threshold used.Ultrasound Obstet Gynecol. 2011; 38: 74-81
- Does induction of labor for constitutionally large-for-gestational-age fetuses identified in utero reduce maternal morbidity?.BMC Pregnancy Childbirth. 2014; 14: 156
- Induction of labour versus expectant management for large-for-date fetuses: a randomised controlled trial.Lancet. 2015; 385: 2600-2605
- Insulin-requiring diabetes in pregnancy: a randomized trial of active induction of labor and expectant management.Am J Obstet Gynecol. 1993; 169: 611-615
- Active compared with expectant delivery management in women with gestational diabetes: a systematic review.Obstet Gynecol. 2009; 113: 206-217
- Use of labour induction and risk of cesarean delivery: a systematic review and meta-analysis.CMAJ. 2014; 186: 665-673
- Induction of labour for improving birth outcomes for women at or beyond term.Cochrane Database Syst Rev. 2012; 6CD004945
- Induction of labor before 40 weeks is associated with lower rate of cesarean delivery in women with gestational diabetes mellitus.Am J Obstet Gynecol. 2016; 214 (e1-8): 364
- Gestational diabetes mellitus in women receiving beta-adrenergics and corticosteroids for threatened preterm delivery.Obstet Gynecol. 1997; 90: 880-883
- Fatal foetal outcome from diabetic ketoacidosis in pregnancy.Anaesth Intensive Care. 1995; 23: 234-237
- Outcome of pregnancy in diabetic ketoacidosis.Am J Perinatol. 1993; 10: 17-20
- Starvation ketoacidosis: a cause of severe anion gap metabolic acidosis in pregnancy.Case Rep Crit Care. 2014; 2014906283
- Antenatal Betamethasone for Women at Risk for Late Preterm Delivery.N Engl J Med. 2016;
- Corticosteroids for preventing neonatal respiratory morbidity after elective caesarean section at term.Cochrane Database Syst Rev. 2009; CD006614
- Effects of early breastfeeding on neonatal glucose levels of term infants born to women with gestational diabetes.J Hum Nutr Diet. 2009; 22: 166-169
- Nutrition for healthy term infants, birth to six months: An overview.Paediatr Child Health. 2013; 18: 206-209
- Lactation intensity and postpartum maternal glucose tolerance and insulin resistance in women with recent GDM: the SWIFT cohort.Diabetes Care. 2012; 35: 50-56
- Association of breast-feeding and early childhood overweight in children from mothers with gestational diabetes mellitus.Diabetes Care. 2006; 29: 1105-1107
- Gestational diabetes mellitus.J Clin Invest. 2005; 115: 485-491
- The risk of overt diabetes mellitus among women with gestational diabetes: a population-based study.Diabet Med. 2010; 27: 779-785
- Manifestations of chronic disease during pregnancy.JAMA. 2005; 294: 2751-2757
- Gestational diabetes and the incidence of type 2 diabetes: a systematic review.Diabetes Care. 2002; 25: 1862-1868
- Rates of postpartum glucose testing after gestational diabetes mellitus.Obstet Gynecol. 2006; 108: 1456-1462
- Lactation and Progression to Type 2 Diabetes Mellitus After Gestational Diabetes Mellitus: A Prospective Cohort Study.Ann Intern Med. 2015; 163: 889-898
- International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy.Diabetes Care. 2010; 33: 676-682
Article info
Publication history
No. 393, December 2019 (replaces No. 334, July 2016)
Footnotes
This document reflects emerging clinical and scientific advances on the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed. Local institutions can dictate amendments to these opinions. They should be well documented if modified at the local level. None of these contents may be reproduced in any form without prior written permission of the publisher.
All people have the right and responsibility to make informed decisions about their care in partnership with their health care providers. In order to facilitate informed choice, patients should be provided with information and support that is evidence-based, culturally appropriate and tailored to their needs.
This guideline was written using language that places women at the centre of care. That said, the SOGC is committed to respecting the rights of all people—including transgender, gender non-binary, and intersex people—for whom the guideline may apply. We encourage healthcare providers to engage in respectful conversation with patients regarding their gender identity as a critical part of providing safe and appropriate care. The values, beliefs and individual needs of each patient and their family should be sought and the final decision about the care and treatment options chosen by the patient should be respected.
Identification
Copyright
© 2019 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.
ScienceDirect
Access this article on ScienceDirectLinked Article
- Corrigendum to “Guideline No. 393-Diabetes in Pregnancy” [Journal of Obstetrics and Gynaecology Canada 41/12 (2019) 1814–1825]Journal of Obstetrics and Gynaecology Canada Vol. 42Issue 10
