Gestational diabetes mellitus
- Overview
- Theory
- Diagnosis
- Management
- Follow up
- Resources
Treatment algorithm
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer
fasting plasma glucose ≥7 mmol/L (≥126 mg/dL), or 6 to 6.9 mmol/L (108-124 mg/dL) if large fetus/polyhydramnios
insulin
The UK National Institute for Health and Care Excellence (NICE) recommends immediate initiation of insulin for women with GDM who:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Have a fasting plasma glucose level ≥7.0 mmol/L (≥126 mg/dL) at diagnosis
Have a fasting plasma glucose level of 6.0 to 6.9 mmol/L (108-124 mg/dL) at diagnosis in the presence of a large-for-gestational-age fetus or polyhydramnios.
This is in order to get glucose levels controlled as quickly as possible. Patients started on insulin are likely to have insulin prescribed throughout pregnancy.
Insulin needs are highly variable. Requirements increase throughout pregnancy and average 0.8 units/kg/day in the first trimester, 1 unit/kg/day in the second trimester, and 1.2 units/kg/day in the third trimester.[62]Gabbe SG, Graves CR. Management of diabetes mellitus complicating pregnancy. Obstet Gynecol. 2003 Oct;102(4):857-68. http://www.ncbi.nlm.nih.gov/pubmed/14551019?tool=bestpractice.com
Insulin therapy requires highly individualised titration.
For isolated fasting hyperglycaemia, use intermediate-acting insulin (e.g., insulin isophane NPH [Neutral Protamine Hagedorn]) or long-acting insulin (e.g., insulin detemir, insulin glargine) at bedtime and then adjust the dose to achieve fasting blood glucose <5.3 mmol/L (<95 mg/dL).[79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com
To address post-prandial hyperglycaemia, one approach is to use intermediate-acting or long-acting insulin once or twice daily, with short- or rapid-acting prandial insulin (e.g., insulin lispro, insulin aspart) titrated to meet glycaemic targets.[79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com
Insulin is titrated according to maternal dietary intake to meet target blood glucose levels.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 [49]Committee on Practice Bulletins - Obstetrics. ACOG practice bulletin no. 190: gestational diabetes mellitus. Obstet Gynecol. 2018 Feb;131(2):e49-64. http://www.ncbi.nlm.nih.gov/pubmed/29370047?tool=bestpractice.com
In the UK, NICE recommends insulin isophane NPH as the first choice for background insulin during pregnancy, given once (to provide night-time coverage) or twice daily, although insulin detemir and insulin glargine are also commonly used. NICE also states that the rapid-acting insulin analogues, insulin lispro and insulin aspart, have advantages over soluble human insulin during pregnancy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Human and analogue insulins are the most extensively studied in pregnancy and are generally considered safe. Evidence suggests that the rapid-acting insulin analogues, insulin lispro and insulin aspart, are also safe in pregnancy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 [21]Metzger BE, Buchanan TA, Coustan DR, et al. Summary and recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes Care. 2007 Jul;30 Suppl 2:S251-60. https://care.diabetesjournals.org/content/30/Supplement_2/S251.full http://www.ncbi.nlm.nih.gov/pubmed/17596481?tool=bestpractice.com [80]Edson EJ, Bracco OL, Vambergue A, et al. Managing diabetes during pregnancy with insulin lispro: a safe alternative to human insulin. Endocrine Pract. 2010 Nov-Dec;16(6):1020-7. http://www.ncbi.nlm.nih.gov/pubmed/20439245?tool=bestpractice.com [81]Pollex E, Moretti ME, Koren G, et al. Safety of insulin glargine use in pregnancy: a systematic review and meta-analysis. Ann Pharmacother. 2011 Jan;45(1):9-16. http://www.ncbi.nlm.nih.gov/pubmed/21205954?tool=bestpractice.com These rapid-acting insulins offer increased convenience and improved post-prandial control; however, there is little information to support superiority of any insulin analogue type either during or outside of pregnancy.[79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com [82]Singh SR, Ahmad F, Lal A, et al. Efficacy and safety of insulin analogues for the management of diabetes mellitus: a meta-analysis. CMAJ. 2009 Feb 17;180(4):385-97. http://www.ncbi.nlm.nih.gov/pubmed/19221352?tool=bestpractice.com None of the current human insulins cross the human placenta at normal therapeutic doses.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 [79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com Although there is more limited experience with long-acting insulin detemir and insulin glargine, there is no evidence of adverse maternal or fetal outcomes.[81]Pollex E, Moretti ME, Koren G, et al. Safety of insulin glargine use in pregnancy: a systematic review and meta-analysis. Ann Pharmacother. 2011 Jan;45(1):9-16. http://www.ncbi.nlm.nih.gov/pubmed/21205954?tool=bestpractice.com [83]Wang H, Wender-Ozegowska E, Garne E, et al. Insulin analogues use in pregnancy among women with pregestational diabetes mellitus and risk of congenital anomaly: a retrospective population-based cohort study. BMJ Open. 2018 Feb 24;8(2):e014972. https://bmjopen.bmj.com/content/8/2/e014972.long http://www.ncbi.nlm.nih.gov/pubmed/29478010?tool=bestpractice.com [84]Lv S, Wang J, Xu Y. Safety of insulin analogs during pregnancy: a meta-analysis. Arch Gynecol Obstet. 2015 Apr 9;292(4):749-56. http://www.ncbi.nlm.nih.gov/pubmed/25855052?tool=bestpractice.com Experience in pregnancy with the rapid-acting insulin glulisine is limited, and this insulin analogue should be used only when benefit is thought to outweigh risk relative to other insulins.[85]Doder Z, Vanechanos D, Oster M, et al. Insulin glulisine in pregnancy - experience from clinical trials and post-marketing surveillance. Eur Endocrinol. 2015 Apr 11;11(1):17-20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819056 http://www.ncbi.nlm.nih.gov/pubmed/29632561?tool=bestpractice.com
Advise any woman who is taking insulin about the risks of hypoglycaemia and impaired awareness of hypoglycaemia during pregnancy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Pregnant women taking insulin should always have a fast-acting form of glucose available (e.g., dextrose tablets or glucose-containing drinks).
Primary options
Isolated fasting hyperglycaemia
insulin isophane human (NPH)
OR
Isolated fasting hyperglycaemia
insulin detemir
OR
Isolated fasting hyperglycaemia
insulin glargine
OR
Postprandial hyperglycaemia
insulin isophane human (NPH)
or
insulin detemir
or
insulin glargine
-- AND --
insulin lispro
or
insulin aspart
metformin
Additional treatment recommended for SOME patients in selected patient group
Guidelines differ on the use of oral anti-hyperglycaemic agents (e.g., metformin) in women with GDM. Their role remains a matter of debate, largely owing to historically sparse data on long-term offspring outcomes, although in practice they are widely used.[66]Barbour LA, Feig DS. Metformin for gestational diabetes mellitus: progeny, perspective, and a personalized approach. Diabetes Care. 2019 Mar;42(3):396-9. https://www.doi.org/10.2337/dci18-0055 http://www.ncbi.nlm.nih.gov/pubmed/30787061?tool=bestpractice.com Check your local protocol.
One large, register-based cohort study from Finland found no increased long-term risk to offspring associated with pregnancy exposure to metformin compared with insulin.[67]Brand KMG, Saarelainen L, Sonajalg J, et al. Metformin in pregnancy and risk of adverse long-term outcomes: a register-based cohort study. BMJ Open Diabetes Res Care. 2022 Jan;10(1):e002363. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8734020 http://www.ncbi.nlm.nih.gov/pubmed/34987051?tool=bestpractice.com Following a European review of data from this study, the metformin prescribing information now states that it can be considered for use during pregnancy and the periconceptional phase as an addition or an alternative to insulin, if clinically needed. Thus, while metformin is not specifically licensed in the UK for the treatment of gestational diabetes, it can be used in pregnancy for both pre-existing and gestational diabetes.
NICE recommends to:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Consider metformin as an adjunct for any woman with GDM who is treated with insulin.
Metformin reduces hyperglycaemia by decreasing hepatic gluconeogenesis and glycogenolysis. Limited evidence is available to suggest that it decreases the composite outcome of infant mortality or serious morbidity.
[ ]
How do different oral anti‐diabetic pharmacological therapies compare for treatment of women with gestational diabetes?/cca.html?targetUrl=https://www.cochranelibrary.com/cca/doi/10.1002/cca.1667/fullShow me the answer One systematic review comparing outcomes of GDM treated with oral antihyperglycaemic agents versus insulin found that metformin and insulin therapy yielded similar outcomes.[68]Nicholson W, Bolen S, Witkop CT, et al. Benefits and risks of oral diabetes agents compared with insulin in women with gestational diabetes: a systematic review. Obstet Gynecol. 2009 Jan;113(1):193-205.
http://www.ncbi.nlm.nih.gov/pubmed/19104375?tool=bestpractice.com
One meta-analysis of 35 randomised controlled trials (RCTs) reporting on pregnancy outcomes in women who used metformin for any indication found that gestational weight gain was lower in women randomised to metformin versus other treatments (1.57 kg ± 0.60 kg). The risk of pre-eclampsia was also reduced (OR 0.69, 95% CI 0.50 to 0.95) but the risk of gastrointestinal side-effects was greater in women taking metformin compared with other treatment groups.[69]Tarry-Adkins JL, Ozanne SE, Aiken CE. Impact of metformin treatment during pregnancy on maternal outcomes: a systematic review/meta-analysis. Sci Rep. 2021 Apr 29;11(1):9240.
https://www.doi.org/10.1038/s41598-021-88650-5
http://www.ncbi.nlm.nih.gov/pubmed/33927270?tool=bestpractice.com
Metformin freely crosses the placenta to achieve measurable concentrations in cord blood at concentrations similar to or higher than the maternal concentration.[70]Schwartz RA, Rosenn B, Aleksa K, et al. Glyburide transport across the human placenta. Obstet Gynecol. 2015 Mar;125(3):583-8. http://www.ncbi.nlm.nih.gov/pubmed/25730219?tool=bestpractice.com [71]Vanky E, Zahlsen K, Spigset O, et al. Placental passage of metformin in women with polycystic ovary syndrome. Fertil Steril. 2005 May;83(5):1575-8. https://www.doi.org/10.1016/j.fertnstert.2004.11.051 http://www.ncbi.nlm.nih.gov/pubmed/15866611?tool=bestpractice.com [72]Eyal S, Easterling TR, Carr D, et al. Pharmacokinetics of metformin during pregnancy. Drug Metab Dispos. 2010 May;38(5):833-40. http://www.ncbi.nlm.nih.gov/pubmed/20118196?tool=bestpractice.com Despite this, follow-up data have suggested no adverse developmental effects and no early differences in overall body composition in offspring.[67]Brand KMG, Saarelainen L, Sonajalg J, et al. Metformin in pregnancy and risk of adverse long-term outcomes: a register-based cohort study. BMJ Open Diabetes Res Care. 2022 Jan;10(1):e002363. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8734020 http://www.ncbi.nlm.nih.gov/pubmed/34987051?tool=bestpractice.com [73]Rowan JA, Rush EC, Obolonkin V, et al. Metformin in gestational diabetes: the offspring follow-up (MiG TOFU): body composition at 2 years of age. Diabetes Care. 2011 Oct;34(10):2279-84. http://care.diabetesjournals.org/content/34/10/2279.long http://www.ncbi.nlm.nih.gov/pubmed/21949222?tool=bestpractice.com [74]Ijäs H, Vääräsmäki M, Saarela T, et al. A follow-up of a randomised study of metformin and insulin in gestational diabetes mellitus: growth and development of the children at the age of 18 months. BJOG. 2015 Jun;122(7):994-1000. http://www.ncbi.nlm.nih.gov/pubmed/25039582?tool=bestpractice.com Some commentators have recommended that due to the potential for growth restriction or acidosis in the setting of placental insufficiency, metformin should not be used if the fetus is at risk of experiencing an ischaemic environment, including placental insufficiency, hypertension, pre-eclampsia, or growth restriction.[66]Barbour LA, Feig DS. Metformin for gestational diabetes mellitus: progeny, perspective, and a personalized approach. Diabetes Care. 2019 Mar;42(3):396-9. https://www.doi.org/10.2337/dci18-0055 http://www.ncbi.nlm.nih.gov/pubmed/30787061?tool=bestpractice.com
A modified-release formulation is available for people who are unable to tolerate the gastrointestinal adverse effects associated with the immediate-release formulation.
Primary options
metformin: 500 mg orally (immediate-release) once daily for at least one week, followed by 500 mg twice daily for at least one week, then 500 mg three times daily thereafter, maximum 2000 mg/day
More metforminAlso available as a modified-release formulation.
blood glucose monitoring
Treatment recommended for ALL patients in selected patient group
Self-monitoring of blood glucose is initiated to assess fasting and post-prandial glycaemia and guide therapy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 NICE recommends the following:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Advise all women with GDM to test their fasting and 1-hour post-meal capillary glucose levels daily.
If a woman with GDM is on multiple daily insulin injections, advise her to also test glucose levels before meals and at bedtime.
Advise women with GDM to maintain their capillary plasma glucose below the following target levels:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Fasting: 5.3 mmol/L (95 mg/dL)
1 hour after meals: 7.8 mmol/L (140 mg/dL)
2 hours after meals: 6.4 mmol/L (115 mg/dL).
These target levels are the same as for any pregnant woman with any form of diabetes.
If the above targets cannot be achieved without problematic hypoglycaemia, agree individualised targets that take account of that risk.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Women taking insulin should also aim to keep their capillary glucose levels above 4 mmol/L (72 mg/dL).[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
In women treated for GDM, higher median fasting glucose during the first 2 weeks of diet therapy was associated with increased neonatal fat mass and elevated C-peptide; during the last 2 weeks before delivery it was associated with macrosomia, large-for-gestational-age fetus, and elevated C-peptide.[60]Durnwald CP, Mele L, Spong CY, et al. Glycemic characteristics and neonatal outcomes of women treated for mild gestational diabetes. Obstet Gynecol. 2011 Apr;117(4):819-27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3282599 http://www.ncbi.nlm.nih.gov/pubmed/21422852?tool=bestpractice.com
diet and exercise
Treatment recommended for ALL patients in selected patient group
Refer any woman with GDM to a registered dietitian, if available.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 [4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 [21]Metzger BE, Buchanan TA, Coustan DR, et al. Summary and recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes Care. 2007 Jul;30 Suppl 2:S251-60. https://care.diabetesjournals.org/content/30/Supplement_2/S251.full http://www.ncbi.nlm.nih.gov/pubmed/17596481?tool=bestpractice.com
Expert opinion suggests that women should be advised to choose carbohydrates from low glycaemic index (GI) sources and lean proteins.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Caloric needs are determined by pre-pregnancy ideal body weight according to expert opinion: 30 kcal/kg for those with normal weight and 35 kcal/kg for underweight patients.[62]Gabbe SG, Graves CR. Management of diabetes mellitus complicating pregnancy. Obstet Gynecol. 2003 Oct;102(4):857-68. http://www.ncbi.nlm.nih.gov/pubmed/14551019?tool=bestpractice.com
Evidence suggests that a low GI diet may be the best option for women with GDM. While some studies have suggested reducing carbohydrates to 40% to 45% of total daily calories reduces post-prandial hyperglycaemia, a meta-analysis of dietary interventions concluded that a low GI diet was associated with a less frequent need for insulin and lower infant birth weights than calorie-restricted diets, low carbohydrate diets, or other diets.[63]Franz MJ, Bantle JP, Beebe CA, et al. Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications. Diabetes Care. 2002 Jan;25(1):148-98. http://care.diabetesjournals.org/content/25/1/148.full http://www.ncbi.nlm.nih.gov/pubmed/11772915?tool=bestpractice.com [64]Viana LV, Gross JL, Azevedo MJ. Dietary intervention in patients with gestational diabetes mellitus: a systematic review and meta-analysis of randomized clinical trials on maternal and newborn outcomes. Diabetes Care. 2014 Dec;37(12):3345-55. http://care.diabetesjournals.org/content/37/12/3345.long http://www.ncbi.nlm.nih.gov/pubmed/25414390?tool=bestpractice.com
The American Diabetes Association recommends a diet with a balance of macronutrients (i.e., carbohydrates, protein, fats), including nutrient-dense whole foods such as fruits, vegetables, legumes, whole grains, and foods containing healthy fats with n-3 fatty acids (e.g., nuts, seeds, fish).[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 A diet that severely restricts any macronutrient class should be avoided.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1
Moderate-intensity exercise during pregnancy (e.g., brisk walking, easy jogging, or swimming) is recommended and has been associated with lowering of maternal glucose levels in some but not all studies.[65]Harrison AL, Shields N, Taylor NF, et al. Exercise improves glycaemic control in women diagnosed with gestational diabetes mellitus: a systematic review. J Physiother. 2016 Oct;62(4):188-96. http://www.journalofphysiotherapy.com/article/S1836-9553(16)30053-4/fulltext http://www.ncbi.nlm.nih.gov/pubmed/27637772?tool=bestpractice.com
NICE recommends that women with GDM should be advised to exercise regularly (e.g., walking for 30 minutes after a meal).[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
ultrasound monitoring of fetal growth and amniotic fluid volume
Additional treatment recommended for SOME patients in selected patient group
Protocols for antenatal fetal monitoring for women with GDM vary, so check your local protocol.
In the UK, NICE recommends the following:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Offer ultrasound assessment of fetal growth and amniotic fluid volume every 4 weeks from 28 to 36 weeks of gestation.
If problems are identified, more frequent ultrasound assessments may be required. In line with the NHS England Saving Babies’ Lives Version Three Care Bundle, all women should be made aware of the importance of monitoring fetal movements and seeking medical review if their baby’s movements are reduced.[86]NHS England. Saving babies’ lives version three: a care bundle for reducing perinatal mortality. Jun 2023 [internet publication]. https://www.england.nhs.uk/publication/saving-babies-lives-version-three
Ultrasonographic estimates of fetal weight may be useful in planning route of delivery, with recognised limitations.
NICE recommends against the routine use of fetal artery doppler recording, fetal heart rate recording, and biophysical profile testing before 38 weeks of gestation, unless there is a risk of fetal growth restriction.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
fasting plasma glucose <7 mmol/L (<126 mg/dL) without large fetus/polyhydramnios
trial of diet and exercise changes
Dietary advice is central to the control of GDM, and many women are adequately treated with diet and lifestyle modification alone. However, data are limited concerning different types of dietary advice.[61]Han S, Middleton P, Shepherd E, et al. Different types of dietary advice for women with gestational diabetes mellitus. Cochrane Database Syst Rev. 2017 Feb 25;(2):CD009275. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD009275.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/28236296?tool=bestpractice.com
The UK National Institute for Health and Care Excellence (NICE) recommends a 1 to 2 week trial of diet and exercise changes alone for women with GDM who have a fasting plasma glucose (FPG) <7 mmol/L (<126 mg/dL) at diagnosis (and who have no complications such as a large-for-gestational-age fetus or hydramnios).[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 [Evidence C]0b19eb31-de2b-46ce-ab48-f18eebb286f9guidelineCWhat are the effects of diet and exercise for the management of gestational diabetes?[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Refer any woman with GDM to a registered dietitian, if available.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 [4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 [21]Metzger BE, Buchanan TA, Coustan DR, et al. Summary and recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes Care. 2007 Jul;30 Suppl 2:S251-60. https://care.diabetesjournals.org/content/30/Supplement_2/S251.full http://www.ncbi.nlm.nih.gov/pubmed/17596481?tool=bestpractice.com
Expert opinion suggests that women should be advised to choose carbohydrates from low glycaemic index (GI) sources and lean proteins.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Caloric needs are determined by pre-pregnancy ideal body weight according to expert opinion: 30 kcal/kg for those with normal weight and 35 kcal/kg for underweight patients.[62]Gabbe SG, Graves CR. Management of diabetes mellitus complicating pregnancy. Obstet Gynecol. 2003 Oct;102(4):857-68. http://www.ncbi.nlm.nih.gov/pubmed/14551019?tool=bestpractice.com
Evidence suggests that a low GI diet may be the best option for women with GDM. While some studies have suggested reducing carbohydrates to 40% to 45% of total daily calories reduces post-prandial hyperglycaemia, a meta-analysis of dietary interventions concluded that a low GI diet was associated with a less frequent need for insulin and lower infant birth weights than calorie-restricted diets, low carbohydrate diets, or other diets.[63]Franz MJ, Bantle JP, Beebe CA, et al. Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications. Diabetes Care. 2002 Jan;25(1):148-98. http://care.diabetesjournals.org/content/25/1/148.full http://www.ncbi.nlm.nih.gov/pubmed/11772915?tool=bestpractice.com [64]Viana LV, Gross JL, Azevedo MJ. Dietary intervention in patients with gestational diabetes mellitus: a systematic review and meta-analysis of randomized clinical trials on maternal and newborn outcomes. Diabetes Care. 2014 Dec;37(12):3345-55. http://care.diabetesjournals.org/content/37/12/3345.long http://www.ncbi.nlm.nih.gov/pubmed/25414390?tool=bestpractice.com
The American Diabetes Association recommends a diet with a balance of macronutrients (i.e., carbohydrates, protein, fats), including nutrient-dense whole foods such as fruits, vegetables, legumes, whole grains, and foods containing healthy fats with n-3 fatty acids (e.g., nuts, seeds, fish).[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 A diet that severely restricts any macronutrient class should be avoided.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1
Moderate-intensity exercise during pregnancy (e.g., brisk walking, easy jogging, or swimming) is recommended and has been associated with lowering of maternal glucose levels in some but not all studies.[65]Harrison AL, Shields N, Taylor NF, et al. Exercise improves glycaemic control in women diagnosed with gestational diabetes mellitus: a systematic review. J Physiother. 2016 Oct;62(4):188-96. http://www.journalofphysiotherapy.com/article/S1836-9553(16)30053-4/fulltext http://www.ncbi.nlm.nih.gov/pubmed/27637772?tool=bestpractice.com
NICE recommends that women with GDM should be advised to exercise regularly (e.g., walking for 30 minutes after a meal).[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
blood glucose monitoring
Treatment recommended for ALL patients in selected patient group
Self-monitoring of blood glucose is initiated to assess fasting and post-prandial glycaemia and guide therapy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 The UK National Institute for Health and Care Excellence (NICE) recommends the following:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Advise all women with GDM to test their fasting and 1-hour post-meal capillary glucose levels daily
If a woman with GDM is on multiple daily insulin injections, advise her to also test glucose levels before meals and at bedtime.
Advise women with GDM to maintain their capillary plasma glucose below the following target levels:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Fasting: 5.3 mmol/L (95 mg/dL)
1 hour after meals: 7.8 mmol/L (140 mg/dL)
2 hours after meals: 6.4 mmol/L (115 mg/dL).
These target levels are the same as for any pregnant woman with any form of diabetes.
If the above targets cannot be achieved without problematic hypoglycaemia, agree individualised targets that take account of that risk.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Women taking insulin should also aim to keep their capillary glucose levels above 4 mmol/L (72 mg/dL).[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
In women treated for GDM, higher median fasting glucose during the first 2 weeks of diet therapy was associated with increased neonatal fat mass and elevated C-peptide; during the last 2 weeks before delivery it was associated with macrosomia, large-for-gestational-age fetus, and elevated C-peptide.[60]Durnwald CP, Mele L, Spong CY, et al. Glycemic characteristics and neonatal outcomes of women treated for mild gestational diabetes. Obstet Gynecol. 2011 Apr;117(4):819-27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3282599 http://www.ncbi.nlm.nih.gov/pubmed/21422852?tool=bestpractice.com
ultrasound monitoring of fetal growth and amniotic fluid volume
Additional treatment recommended for SOME patients in selected patient group
Protocols for antenatal fetal monitoring for women with GDM vary, so check your local protocol.
In the UK, NICE recommends the following:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Offer ultrasound assessment of fetal growth and amniotic fluid volume every 4 weeks from 28 to 36 weeks of gestation.
If problems are identified, more frequent ultrasound assessments may be required. In line with the NHS England Saving Babies’ Lives Version Three Care Bundle, all women should be made aware of the importance of monitoring fetal movements and seeking medical review if their baby’s movements are reduced.[86]NHS England. Saving babies’ lives version three: a care bundle for reducing perinatal mortality. Jun 2023 [internet publication]. https://www.england.nhs.uk/publication/saving-babies-lives-version-three
Ultrasonographic estimates of fetal weight may be useful in planning route of delivery, with recognised limitations.
NICE recommends against the routine use of fetal artery doppler recording, fetal heart rate recording, and biophysical profile testing before 38 weeks of gestation, unless there is a risk of fetal growth restriction.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
metformin
Guidelines differ on the use of oral anti-hyperglycaemic agents (e.g., metformin) in women with GDM whose glucose levels are not controlled by diet and exercise. Their role remains a matter of debate, largely owing to historically sparse data on long-term offspring outcomes, although in practice they are widely used.[66]Barbour LA, Feig DS. Metformin for gestational diabetes mellitus: progeny, perspective, and a personalized approach. Diabetes Care. 2019 Mar;42(3):396-9. https://www.doi.org/10.2337/dci18-0055 http://www.ncbi.nlm.nih.gov/pubmed/30787061?tool=bestpractice.com Check your local protocol.
One large, register-based cohort study from Finland found no increased long-term risk to offspring associated with pregnancy exposure to metformin compared with insulin.[67]Brand KMG, Saarelainen L, Sonajalg J, et al. Metformin in pregnancy and risk of adverse long-term outcomes: a register-based cohort study. BMJ Open Diabetes Res Care. 2022 Jan;10(1):e002363. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8734020 http://www.ncbi.nlm.nih.gov/pubmed/34987051?tool=bestpractice.com Following a European review of data from this study, the metformin prescribing information now states that it can be considered for use during pregnancy and the periconceptional phase as an addition or an alternative to insulin, if clinically needed. Thus, while metformin is not specifically licensed in the UK for the treatment of gestational diabetes, it can be used in pregnancy for both pre-existing and gestational diabetes.
NICE concluded that metformin is a safe option that can enable some women with GDM to achieve euglycaemia without the need for insulin treatment.[Evidence B]25bda786-7ea5-49a4-b5dc-b5c9415094b3guidelineBWhat are the effects of metformin compared with insulin in women with gestational diabetes?[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 NICE recommends to:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Offer metformin if a woman’s capillary plasma glucose levels are persistently above target levels after 1 to 2 weeks of dietary and exercise changes.
If metformin is contraindicated or not tolerated, offer insulin instead (see 'insulin' section below).[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Metformin reduces hyperglycaemia by decreasing hepatic gluconeogenesis and glycogenolysis. Limited evidence is available to suggest that it decreases the composite outcome of infant mortality or serious morbidity.
[ ]
How do different oral anti‐diabetic pharmacological therapies compare for treatment of women with gestational diabetes?/cca.html?targetUrl=https://www.cochranelibrary.com/cca/doi/10.1002/cca.1667/fullShow me the answer One systematic review comparing outcomes of GDM treated with oral antihyperglycaemic agents versus insulin found that metformin and insulin therapy yielded similar outcomes.[68]Nicholson W, Bolen S, Witkop CT, et al. Benefits and risks of oral diabetes agents compared with insulin in women with gestational diabetes: a systematic review. Obstet Gynecol. 2009 Jan;113(1):193-205.
http://www.ncbi.nlm.nih.gov/pubmed/19104375?tool=bestpractice.com
One meta-analysis of 35 randomised controlled trials (RCTs) reporting on pregnancy outcomes in women who used metformin for any indication found that gestational weight gain was lower in women randomised to metformin versus other treatments (1.57 kg ± 0.60 kg). The risk of pre-eclampsia was also reduced (OR 0.69, 95% CI 0.50 to 0.95) but the risk of gastrointestinal side-effects was greater in women taking metformin compared with other treatment groups.[69]Tarry-Adkins JL, Ozanne SE, Aiken CE. Impact of metformin treatment during pregnancy on maternal outcomes: a systematic review/meta-analysis. Sci Rep. 2021 Apr 29;11(1):9240.
https://www.doi.org/10.1038/s41598-021-88650-5
http://www.ncbi.nlm.nih.gov/pubmed/33927270?tool=bestpractice.com
Metformin freely crosses the placenta to achieve measurable concentrations in cord blood at concentrations similar to or higher than the maternal concentration.[70]Schwartz RA, Rosenn B, Aleksa K, et al. Glyburide transport across the human placenta. Obstet Gynecol. 2015 Mar;125(3):583-8. http://www.ncbi.nlm.nih.gov/pubmed/25730219?tool=bestpractice.com [71]Vanky E, Zahlsen K, Spigset O, et al. Placental passage of metformin in women with polycystic ovary syndrome. Fertil Steril. 2005 May;83(5):1575-8. https://www.doi.org/10.1016/j.fertnstert.2004.11.051 http://www.ncbi.nlm.nih.gov/pubmed/15866611?tool=bestpractice.com [72]Eyal S, Easterling TR, Carr D, et al. Pharmacokinetics of metformin during pregnancy. Drug Metab Dispos. 2010 May;38(5):833-40. http://www.ncbi.nlm.nih.gov/pubmed/20118196?tool=bestpractice.com Despite this, follow-up data have suggested no adverse developmental effects and no early differences in overall body composition in offspring.[67]Brand KMG, Saarelainen L, Sonajalg J, et al. Metformin in pregnancy and risk of adverse long-term outcomes: a register-based cohort study. BMJ Open Diabetes Res Care. 2022 Jan;10(1):e002363. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8734020 http://www.ncbi.nlm.nih.gov/pubmed/34987051?tool=bestpractice.com [73]Rowan JA, Rush EC, Obolonkin V, et al. Metformin in gestational diabetes: the offspring follow-up (MiG TOFU): body composition at 2 years of age. Diabetes Care. 2011 Oct;34(10):2279-84. http://care.diabetesjournals.org/content/34/10/2279.long http://www.ncbi.nlm.nih.gov/pubmed/21949222?tool=bestpractice.com [74]Ijäs H, Vääräsmäki M, Saarela T, et al. A follow-up of a randomised study of metformin and insulin in gestational diabetes mellitus: growth and development of the children at the age of 18 months. BJOG. 2015 Jun;122(7):994-1000. http://www.ncbi.nlm.nih.gov/pubmed/25039582?tool=bestpractice.com Some commentators have recommended that due to the potential for growth restriction or acidosis in the setting of placental insufficiency, metformin should not be used if the fetus is at risk of experiencing an ischaemic environment, including placental insufficiency, hypertension, pre-eclampsia, or growth restriction.[66]Barbour LA, Feig DS. Metformin for gestational diabetes mellitus: progeny, perspective, and a personalized approach. Diabetes Care. 2019 Mar;42(3):396-9. https://www.doi.org/10.2337/dci18-0055 http://www.ncbi.nlm.nih.gov/pubmed/30787061?tool=bestpractice.com
A modified-release formulation is available for people who are unable to tolerate the gastrointestinal adverse effects associated with the immediate-release formulation.
Primary options
metformin: 500 mg orally (immediate-release) once daily for at least one week, followed by 500 mg twice daily for at least one week, then 500 mg three times daily thereafter, maximum 2000 mg/day
More metforminAlso available as a modified-release formulation.
insulin
Additional treatment recommended for SOME patients in selected patient group
NICE recommends initiation of insulin for women with an FPG level <7.0 mmol/L (<126 mg/dL) at diagnosis who cannot meet their blood glucose targets with diet and exercise changes plus metformin. Metformin may be continued. If metformin is contraindicated or not tolerated, offer insulin instead.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Insulin needs are highly variable. Requirements increase throughout pregnancy and average 0.8 units/kg/day in the first trimester, 1 unit/kg/day in the second trimester, and 1.2 units/kg/day in the third trimester.[62]Gabbe SG, Graves CR. Management of diabetes mellitus complicating pregnancy. Obstet Gynecol. 2003 Oct;102(4):857-68. http://www.ncbi.nlm.nih.gov/pubmed/14551019?tool=bestpractice.com
Insulin therapy requires highly individualised titration.
For isolated fasting hyperglycaemia, use intermediate-acting insulin (e.g., insulin isophane NPH [Neutral Protamine Hagedorn]) or long-acting insulin (e.g., insulin isophane detemir, insulin glargine) at bedtime and then adjust the dose to achieve fasting blood glucose <5.3 mmol/L (<95 mg/dL).[79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com
To address post-prandial hyperglycaemia, one approach is to use intermediate-acting or long-acting insulin once or twice daily, with short- or rapid-acting prandial insulin (e.g., insulin lispro, insulin aspart) titrated to meet glycaemic targets.[79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com
Insulin is titrated according to maternal dietary intake to meet target blood glucose levels.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 [49]Committee on Practice Bulletins - Obstetrics. ACOG practice bulletin no. 190: gestational diabetes mellitus. Obstet Gynecol. 2018 Feb;131(2):e49-64. http://www.ncbi.nlm.nih.gov/pubmed/29370047?tool=bestpractice.com
In the UK, NICE recommends insulin isophane NPH as the first choice for background insulin during pregnancy, given once (to provide night-time coverage) or twice daily, although insulin detemir and insulin glargine are also commonly used. NICE also states that the rapid-acting insulin analogues, insulin lispro and insulin aspart, have advantages over soluble human insulin during pregnancy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Human and analogue insulins are the most extensively studied in pregnancy and are generally considered safe. Evidence suggests that the rapid-acting insulin analogues, insulin lispro and insulin aspart, are also safe in pregnancy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 [21]Metzger BE, Buchanan TA, Coustan DR, et al. Summary and recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes Care. 2007 Jul;30 Suppl 2:S251-60. https://care.diabetesjournals.org/content/30/Supplement_2/S251.full http://www.ncbi.nlm.nih.gov/pubmed/17596481?tool=bestpractice.com [80]Edson EJ, Bracco OL, Vambergue A, et al. Managing diabetes during pregnancy with insulin lispro: a safe alternative to human insulin. Endocrine Pract. 2010 Nov-Dec;16(6):1020-7. http://www.ncbi.nlm.nih.gov/pubmed/20439245?tool=bestpractice.com [81]Pollex E, Moretti ME, Koren G, et al. Safety of insulin glargine use in pregnancy: a systematic review and meta-analysis. Ann Pharmacother. 2011 Jan;45(1):9-16. http://www.ncbi.nlm.nih.gov/pubmed/21205954?tool=bestpractice.com These rapid-acting insulins offer increased convenience and improved post-prandial control; however, there is little information to support superiority of any insulin analogue type either during or outside of pregnancy.[82]Singh SR, Ahmad F, Lal A, et al. Efficacy and safety of insulin analogues for the management of diabetes mellitus: a meta-analysis. CMAJ. 2009 Feb 17;180(4):385-97. http://www.ncbi.nlm.nih.gov/pubmed/19221352?tool=bestpractice.com [79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com None of the current human insulins cross the human placenta at normal therapeutic doses.[3]American Diabetes Association. Standards of care in diabetes - 2023. Diabetes Care. 2023 Jan;46(Suppl 1):S1-291. https://diabetesjournals.org/care/issue/46/Supplement_1 [79]Brown J, Grzeskowiak L, Williamson K, et al. Insulin for the treatment of women with gestational diabetes. Cochrane Database Syst Rev. 2017 Nov 5;(11):CD012037. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012037.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/29103210?tool=bestpractice.com Although there is more limited experience with long-acting insulin detemir and insulin glargine, there is no evidence of adverse maternal or fetal outcomes.[81]Pollex E, Moretti ME, Koren G, et al. Safety of insulin glargine use in pregnancy: a systematic review and meta-analysis. Ann Pharmacother. 2011 Jan;45(1):9-16. http://www.ncbi.nlm.nih.gov/pubmed/21205954?tool=bestpractice.com [83]Wang H, Wender-Ozegowska E, Garne E, et al. Insulin analogues use in pregnancy among women with pregestational diabetes mellitus and risk of congenital anomaly: a retrospective population-based cohort study. BMJ Open. 2018 Feb 24;8(2):e014972. https://bmjopen.bmj.com/content/8/2/e014972.long http://www.ncbi.nlm.nih.gov/pubmed/29478010?tool=bestpractice.com [84]Lv S, Wang J, Xu Y. Safety of insulin analogs during pregnancy: a meta-analysis. Arch Gynecol Obstet. 2015 Apr 9;292(4):749-56. http://www.ncbi.nlm.nih.gov/pubmed/25855052?tool=bestpractice.com Experience in pregnancy with the rapid-acting insulin glulisine is limited, and this insulin analogue should be used only when benefit is thought to outweigh risk relative to other insulins.[85]Doder Z, Vanechanos D, Oster M, et al. Insulin glulisine in pregnancy - experience from clinical trials and post-marketing surveillance. Eur Endocrinol. 2015 Apr 11;11(1):17-20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819056 http://www.ncbi.nlm.nih.gov/pubmed/29632561?tool=bestpractice.com
Advise any woman who is taking insulin about the risks of hypoglycaemia and impaired awareness of hypoglycaemia during pregnancy.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Pregnant women taking insulin should always have a fast-acting form of glucose available (e.g., dextrose tablets or glucose-containing drinks).
Primary options
Isolated fasting hyperglycaemia
insulin isophane human (NPH)
OR
Isolated fasting hyperglycaemia
insulin detemir
OR
Isolated fasting hyperglycaemia
insulin glargine
OR
Postprandial hyperglycaemia
insulin isophane human (NPH)
or
insulin detemir
or
insulin glargine
-- AND --
insulin lispro
or
insulin aspart
diet and exercise changes
Treatment recommended for ALL patients in selected patient group
It is important to encourage women to continue with changes to diet and exercise even if these were insufficient on their own to meet blood glucose targets.
ultrasound monitoring of fetal growth and amniotic fluid volume
Additional treatment recommended for SOME patients in selected patient group
Protocols for antenatal fetal monitoring for women with GDM vary, so check your local protocol.
In the UK, NICE recommends the following:[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Offer ultrasound assessment of fetal growth and amniotic fluid volume every 4 weeks from 28 to 36 weeks of gestation.
If problems are identified, more frequent ultrasound assessments may be required. In line with the NHS England Saving Babies’ Lives Version Three Care Bundle, all women should be made aware of the importance of monitoring fetal movements and seeking medical review if their baby’s movements are reduced.[86]NHS England. Saving babies’ lives version three: a care bundle for reducing perinatal mortality. Jun 2023 [internet publication]. https://www.england.nhs.uk/publication/saving-babies-lives-version-three
Ultrasonographic estimates of fetal weight may be useful in planning route of delivery, with recognised limitations.
NICE recommends against the routine use of fetal artery doppler recording, fetal heart rate recording, and biophysical profile testing before 38 weeks of gestation, unless there is a risk of fetal growth restriction.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
labour
intrapartum glycaemic control
Advise women with GDM to deliver in a hospital with 24-hour advanced neonatal resuscitation capacity.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
Capillary plasma glucose should be monitored every hour during labour and birth or from the morning of elective caesarean section.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3 [89]Joint British Diabetes Societies for Inpatient Care Group (JBDS-IP). Managing diabetes and hyperglycaemia during labour and birth. Feb 2023 [internet publication]. https://abcd.care/sites/default/files/site_uploads/JBDS_Guidelines_Current/JBDS_12_Managing_diabetes_and_hyperglycaemia_during_labour_and_birth_with_QR_code_February_2023.pdf If general anaesthesia is used, monitoring should be every 30 minutes until the woman is fully conscious.[89]Joint British Diabetes Societies for Inpatient Care Group (JBDS-IP). Managing diabetes and hyperglycaemia during labour and birth. Feb 2023 [internet publication]. https://abcd.care/sites/default/files/site_uploads/JBDS_Guidelines_Current/JBDS_12_Managing_diabetes_and_hyperglycaemia_during_labour_and_birth_with_QR_code_February_2023.pdf
There are no large randomised controlled trials addressing whether intrapartum compared with antenatal glycaemic control lessens the risk of neonatal hypoglycaemia; however, based on limited evidence, avoiding maternal hyperglycaemia during labour in women with GDM is recommended. Intravenous insulin may sometimes be needed to achieve this.[90]Curet LB, Izquierdo LA, Gilson GJ, et al. Relative effects of antepartum and intrapartum maternal blood glucose levels on incidence of neonatal hypoglycemia. J Perinatol. 1997 Mar-Apr;17(2):113-5. http://www.ncbi.nlm.nih.gov/pubmed/9134508?tool=bestpractice.com
The UK National Institute for Health and Care Excellence (NICE) recommends that women whose capillary glucose levels cannot be maintained between 4 and 7 mmol/L (72-126 mg/dL) should be started on intravenous dextrose and insulin infusions.[4]National Institute for Health and Care Excellence. Diabetes in pregnancy: management from preconception to the postnatal period. Dec 2020 [internet publication]. https://www.nice.org.uk/guidance/ng3
The Joint British Diabetes Societies for Inpatient Care Group recommends that glucose levels (capillary, flash, or continuous glucose monitoring ) are maintained during labour in either the target range advocated in the NICE guidelines (4 to 7 mmol/L [72-126 mg/dL]) or in the more liberal range of 5 to 8 mmol/L (90-144 mg/dL) due to lack of randomised controlled trial evidence for either target.[89]Joint British Diabetes Societies for Inpatient Care Group (JBDS-IP). Managing diabetes and hyperglycaemia during labour and birth. Feb 2023 [internet publication]. https://abcd.care/sites/default/files/site_uploads/JBDS_Guidelines_Current/JBDS_12_Managing_diabetes_and_hyperglycaemia_during_labour_and_birth_with_QR_code_February_2023.pdf Some women with GDM may require variable rate intravenous insulin infusion to achieve target glucose levels.[89]Joint British Diabetes Societies for Inpatient Care Group (JBDS-IP). Managing diabetes and hyperglycaemia during labour and birth. Feb 2023 [internet publication]. https://abcd.care/sites/default/files/site_uploads/JBDS_Guidelines_Current/JBDS_12_Managing_diabetes_and_hyperglycaemia_during_labour_and_birth_with_QR_code_February_2023.pdf
Immediately after placental delivery, a large reduction in insulin requirement occurs, and this must be anticipated to avoid hypoglycaemia. Most women with GDM can stop insulin after delivery.
Choose a patient group to see our recommendations
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer
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