Diabetes and pregnancy
Type 1 diabetes and pregnancy
Women with type 1 diabetes who are planning to become pregnant should target an HbA1c below 6.5%1 in order to reduce the risk of adverse outcomes for the mother and baby2.
Optimal glycaemic management at conception and throughout the pregnancy have been associated with lower risk for obstetric and neonatal complications, such as large for gestational age (LGA), admission to neonatal intensive care unit (NICU), preterm live birth and perinatal death.3
Achieving a tight glucose management to protect the foetus from sustained hyperglycaemia without increasing the risk of maternal hypoglycaemia is challenging.
Contributors to successful pregnancies with type 1 diabetes
Healthcare team support: endocrinologists, OBGYNs, diabetes nurses, dietitians, and midwifes play a decisive role in ensuring the safety and well-being of the expectant mother and her child. Receiving intense support with diabetes management has proven to be effective towards achieving better glucose management.4
Diabetes technology: irrespective of diabetes therapy option (MDI or CSII), CGMs have proven to be effective towards achieving better glycaemic management, although insufficient to meet the recommended pregnancy glucose targets.5 The use of AID therapy provides additional benefits, allowing pregnant women to achieve in-range median glucose and HbA1c, without increasing the risk of hypoglycaemia.4
Lifestyle optimisation: weight and stress management, exercise, and diet all contribute towards overall health and achieving more stable glucose values.
Glycaemic targets during pregnancy
As it is critical to protect the foetus from exposure to high glucose levels, the diabetes treatment goals are much stricter for pregnant women:
General consensus on type 1 diabetes management goals pre- and during pregnancy.
Insulin requirements during pregnancy
Unexpected swings in insulin requirements put the mother at risk of imminent hypoglycaemia and hyperglycaemia. Insulin requirements and glucose management vary throughout pregnancy with three changes of direction⁸:
Up to week 16, insulin requirements are more unstable. Because of sudden changes in insulin sensitivity, events of severe hypoglycaemia are more frequent.
At week 16 an upwards trend in total insulin requirements begins.
Capillary blood glucose improves as insulin resistance increases. The best glycaemic management is achieved from week 30 onwards.The image below shows a typical scenario of increased insulin resistance. As pregnancy unfolds, more insulin is required to achieve the same glucose outcome. Adjusting correction and carbohydrate to insulin ratios is crucial to achieve good glycemic control. A closed loop helps with this challenge as it automatically adjusts insulin delivery based on CGM readings and glucose predictions up to 4 hours ahead.
Safety and efficacy of closed loops during pregnancy
The recently published AiDAPT randomised controlled trial⁴ is the largest study conducted on this topic to date. It evaluated CamAPS FX in 61 pregnant women and demonstrated significant improvements in maternal glucose levels compared to standard insulin delivery (63 participants):
Women using CamAPS FX spent more time in the pregnancy specific target range and had lower mean glucose and lower HbA1c levels, compared to women in the control group.
These improvements were achieved without any difference in the time spent in the hypoglycaemic ranges.
The benefits were observed immediately after initiating CamAPS FX and were sustained over the pregnancy period.
All women interviewed reported more enjoyable pregnancy experiences as a result of using closed-loop⁹.
CamAPS is a registered trademark of CamDiab Ltd.
Management of type 1 diabetes during pregnancy under AID
Watch Professor Helen Murphy discuss the key results of the AiDAPT study. She also provides recommendations on managing type 1 diabetes during pregnancy using CamAPS FX.
American Diabetes Association Professional Practice Committee. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2024. Diabetes Care. 2024 Jan 1;47(Suppl 1):S282-S294. doi: 10.2337/dc24-S015. PMID: 38078583; PMCID: PMC10725801.
Diabetes in pregnancy: management from preconception to the postnatal period. NICE guideline [NG3]. Published: 25 Feb 2015. Last updated: 16 Dec 2020. https://www.nice.org.uk/guidance/ng3/chapter/recommendations
National Pregnancy in Diabetes (NPID) Audit Report 2020, England and Wales, 01 Jan 2019 to 31 Dec 2020; published on 14 Oct 2021:https://digital.nhs.uk/data-and-information/publications/statistical/national-pregnancy-in-diabetes-audit/2019-and-2020
Lee TM et al.: Automated Insulin Delivery in Women with Pregnancy Complicated by Type 1 Diabetes: a multicentrerandomized controlled trial. The New England Journal of Medicine. Oct 5, 2023. doi: 10.1056/NEJMoa2303911.
Feig DS et al: Continuous glucose monitoring in pregnant women with type 1 diabetes (CONCEPTT): a multicentre international randomised controlled trial. Lancet. 2017 Nov 25;390(10110):2347-2359. doi: 10.1016/S0140-6736(17)32400-5. Epub 2017 Sep 15. Erratum in: Lancet. 2017 Nov 25;390(10110):2346. PMID: 28923465; PMCID: PMC5713979.
Benhalima K et al.: Management of type 1 diabetes in pregnancy: update onlifestyle, pharmacological treatment, and novel technologies for achieving glycaemic targets. Lancet DiabetesEndocrinol. 2023 Jul;11(7):490-508. doi: 10.1016/S2213-8587(23)00116-X. Epub 2023 Jun 5. Erratum in: LancetDiabetes Endocrinol. 2023 Oct;11(10):e12. PMID: 37290466.
Battelino T et al.: Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range. Diabetes Care 1 August 2019; 42 (8): 1593–1603. doi: 10.2337/dci19-0028.
García-Patterson A et al.: Insulin requirements throughout pregnancy in women with type 1 diabetes mellitus: threechanges of direction. Diabetologia 53, 446–451 (2010); 53: 446-51. doi: 10.1007/s00125-009-1633-z.
Lawton J et al.: Listening to women: experiences of using closed-loop in type 1 diabetes pregnancy. Diabetes TechnolTher. 2023 Oct 5. doi: 10.1089/dia.2023.0323.