Karen Bartha discusses the role of primary care healthcare professionals in the management of pregnant women with pre‑existing diabetes.

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Key points

It is estimated that 5% of women giving birth in England and Wales have either pre-existing diabetes or gestational diabetes, of which 87.5% are estimated to have gestational diabetes, 7.5% have type 1 diabetes, and 5% have type 2 diabetes.1 Since diabetes in pregnancy is associated with risks to both the woman and the developing foetus,2 continued attention must be paid to the well-being of these women prior to, and throughout, pregnancy. While much of this care will fall to specialist antenatal and diabetes services, the role of the primary care healthcare professional (HCP) must be considered in the provision of this care. This article discusses the optimum care of women with diabetes who are planning pregnancy, and pregnant women with pre-existing diabetes. 

Pre-existing diabetes and pregnancy

Women with pre-existing diabetes are at increased risk of complications during pregnancy. Miscarriage, pre‑eclampsia, and preterm labour are more common in this group of patients.1 In addition, diabetic retinopathy can worsen rapidly during pregnancy. Health risks that affect babies born to women with pre-existing diabetes include stillbirth, congenital malformations, macrosomia, birth injury, perinatal mortality, and postnatal adaptation problems (such as hypoglycaemia).1 While it is comforting to know that 99% of registered births in 2016 were live births,3 adverse neonatal outcomes are more common in babies born to mothers with pre-existing diabetes. The National Pregnancy in Diabetes (NPID) Audit reported that in pregnant women with diabetes, there is more than two times increased risk of stillbirth, and four times increased risk of neonatal death when compared with the general population. The rates of congenital anomaly were high at 47.6 per 1000* births for babies born to mothers with pre-existing type 1 diabetes, and 44.8 per 1000* births for babies born to mothers with pre-existing type 2 diabetes.3

* Includes live births and terminations at any gestation, stillbirths and miscarriages after 20 weeks.

Preconception care

Preconception planning can reduce the risk of these health complications, and effective contraception should be used to avoid unplanned pregnancy.

Glycaemic targets

Advise women with diabetes who are planning to become pregnant that they should aim to keep their HbA1c level below 48 mmol/mol (6.5%), if this is achievable without causing problematic hypoglycaemia. Strongly advise women with diabetes whose HbA1c level is above 86 mmol/mol (10%) not to get pregnant because of the associated risks.1 It has been shown that HbA1c levels below 48 mmol/mol reduce the risk of miscarriage, birth defects in babies, stillbirth, and neonatal deaths. Alarmingly, according to the NPID, only 14.9% of women with type 1 diabetes, and 38.1% of women with type 2 diabetes achieve HbA1c levels below 48 mmol/mol,5 and even more worryingly, 7.4% of women with diabetes had a pre-pregnancy HbA1c level of 86 mmol/mol or higher.

To support women to achieve their HbA1c target, advise women with diabetes who are planning to become pregnant to aim for the same capillary plasma glucose target ranges as recommended for all people with type 1 diabetes:

  • a fasting plasma glucose level of 5–7 mmol/litre on waking and
  • a plasma glucose level of 4–7 mmol/litre before meals at other times of the day.1

Folic acid in preconception

Folic acid is known to help reduce the risk of brain and spine defects in babies. This risk is increased in babies born to mothers with diabetes.5 Therefore, women with diabetes who are pregnant or planning pregnancy are advised to take high-dose folic acid supplements (5 mg/day) from at least 3 months before conception until 12 weeks of gestation.1 Unfortunately, NPID data shows that 41.4% of women with type 1 diabetes, and 56.1% of women with type 2 diabetes were found not to be taking folic acid before and during pregnancy.5

Safety of medications in preconception and pregnancy

Women with diabetes may be advised to use metformin as an adjunct or alternative to insulin in the preconception period and during pregnancy, when the likely benefits from improved blood glucose control outweigh the potential for harm. All other oral blood glucose‑lowering agents should be discontinued before pregnancy and insulin substituted.1 Angiotensin‑converting enzyme (ACE) inhibitors and angiotensin‑II receptor antagonists, and statins should be discontinued before conception or as soon as pregnancy is confirmed.1

Diet and lifestyle advice in preconception

Women with diabetes should be encouraged to make healthy lifestyle choices when planning pregnancy, such as eating a well-balanced diet, becoming physically active, stopping smoking, and reducing alcohol intake.6,7 Offer women with diabetes who are planning to become pregnant and who have a body mass index above 27 kg/m2 advice on how to lose weight.1 Preconception advice can be supported with patient information materials, such as Information Prescription—diabetes, contraception and pregnancy (from Diabetes UK)4 or Do you have diabetes? Things to do before you get pregnant (from the Perinatal Institute).7

Retinal assessment

Since diabetic retinopathy can worsen rapidly during pregnancy, offer retinal assessment to women with diabetes seeking preconception care at their first appointment (unless they have had an annual retinal assessment in the last 6 months). Advise women with diabetes who are planning to become pregnant to defer rapid optimisation of blood glucose control until after retinal assessment and treatment have been completed.1

Renal assessment

Offer women with diabetes a renal assessment, including a measure of albuminuria, before discontinuing contraception.1

Referral to specialist services

Consider referral to a specialist diabetes service for preconception support; offer immediate contact with a joint diabetes and antenatal clinic to women with diabetes who are pregnant,8 ideally by 10 weeks.1 Worryingly, NPID data shows that 24% of women with type 1 diabetes, and 41.9% of women with type 2 diabetes did not present to the joint diabetes antenatal team before 10 weeks gestation.5 Elevated HbA1c levels in the first trimester is related to congenital anomaly rates, and in women with type 1 diabetes it was linked to stillbirth and neonatal death,5 which reinforces the need for early specialist intervention.

Antenatal care of women with diabetes during pregnancy

Glycaemic targets

Serious perinatal complications are associated with severe hyperglycaemia in pregnancy (defined as fasting plasma glucose [FPG] <7.8 mmol/litre and median glucose 8.8 mmol/litre following a 75 g oral glucose tolerance test);9 however, the risk can be reduced with treatment.

Treatment has also been shown to have beneficial effects on maternal weight gain, caesarean delivery, pre-eclampsia, pregnancy-induced hypertension, infant birth weight, and neonatal adiposity, in women with both mild (FPG <5.3 mmol/litre) and moderate (FPG <7.8 mmol/litre) hyperglycaemia in pregnancy.9 With this in mind, blood glucose targets for women with diabetes in pregnancy were reduced in 2015, with NICE recommending the following:1

Advise pregnant women with any form of diabetes to maintain their capillary plasma glucose below the following target levels, if these are achievable without causing problematic hypoglycaemia:1

  • fasting: 5.3 mmol/litre and
  • 1 hour after meals: 7.8 mmol/litre or
  • 2 hours after meals: 6.4 mmol/litre.

Glycaemic targets should be achieved with a combination of lifestyle measures and, if indicated, medication. In order to achieve this, women will need to monitor their blood glucose more regularly:1

  • advise pregnant women with type 1 diabetes, and those with type 2 diabetes or gestational diabetes who are on a multiple daily insulin injection regimen to test their fasting, pre‑meal, 1‑hour post‑meal, and bedtime blood glucose levels daily during pregnancy
  • advise pregnant women with type 2 diabetes or gestational diabetes to test their fasting and 1‑hour post‑meal blood glucose levels daily during pregnancy if they are:
    • on diet and exercise therapy or
    • taking oral therapy (with or without diet and exercise therapy) or single‑dose intermediate‑acting or long‑acting insulin.

To further improve neonatal outcomes, The NHS long term plan has pledged that by 2020/2021 continuous glucose monitoring will be offered to all pregnant women with type 1 diabetes.10

Multidisciplinary care

All women with diabetes during pregnancy should receive joint diabetes and antenatal care; where they will be offered retinal and renal assessment, and ongoing monitoring. Tools such as the use of shared Diabetes in pregnancy notes,11 to be used in conjunction with the Pregnancy notes.12 These are designed to facilitate a partnership among the multidisciplinary team and the woman, giving additional information regarding specific care requirements. 

Postnatal care

Women with pre‑existing type 2 diabetes who are breastfeeding can resume or continue to take metformin and glibenclamide immediately after birth, but should avoid other oral blood glucose‑lowering agents while breastfeeding. Women who are breastfeeding should continue to avoid any medicines for the treatment of diabetes complications that were discontinued for safety reasons in the preconception period.1 Remind women with diabetes of the importance of contraception and the need for preconception care when planning future pregnancies.1


Of pregnant women with diabetes, only 1 in 12 (8%) achieve HbA1c below 48 mmol/mol, take 5 mg folic acid, and avoid potentially harmful medications prior to conception.3 This, coupled with the increased risk in adverse outcomes for both the woman and the developing foetus, means that the role of HCPs in discussing the need for planning pregnancy is paramount.

Key points

The role of primary care healthcare professionals in preconception care for women with diabetes:1

  • advise use of safe, effective contraception for all women with diabetes of child-bearing age
  • advise women to achieve good blood glucose management with an HbA1c level of below 48 mmol/mol
  • if HbA1c is above 86 mmol/mol, advise women to avoid pregnancy until they are able to achieve better blood glucose control
  • prescribe 5 mg folic acid to reduce the risk of brain and spinal defects to the foetus
  • stop certain medications that may potentially be harmful, such as oral hypoglycaemic agents other than metformin, ACE inhibitors, angiotensin‑II receptor antagonists, and statins
  • refer women for joint diabetes and antenatal care, ideally by 10 weeks.


  1. NICE. Diabetes in pregnancy: management from preconception to the postnatal period. NICE Guideline 3. NICE 2015. Available at: www.nice.org.uk/guidance/ng3
  2. GP notebook. Gestational diabetes. www.gpnotebook.co.uk/simplepage.cfm?ID=-1529872330 (accessed 11 January 2019).
  3. NHS Digital. National pregnancy in diabetes report 2016. Available at: digital.nhs.uk/data-and-information/publications/statistical/national-pregnancy-in-diabetes-audit/national-pregnancy-in-diabetes-annual-report-2016
  4. Diabetes UK. Information Prescription—diabetes, contraception and pregnancy. diabetes-resources-production.s3-eu-west-1.amazonaws.com/diabetes-storage/2017-08/0655C GP Information Prescriptions_Pregnancy_v6.pdf (accessed 11 January 2019).
  5. Diabetes UK. National Pregnancy in Diabetes Audit: are services providing good quality care for women with diabetes in pregnancy? A summary report of the National Pregnancy in Diabetes Audit for England and Wales 2016. www.diabetes.org.uk/resources-s3/2018-12/NPID_ Summary_v3.pdf (accessed 19 January 2019).
  6. Diabetes UK. Planning for a pregnancy when you have diabetes.www.diabetes.org.uk/guide-to-diabetes/life-with-diabetes/pregnancy (accessed 11 January 2019).
  7. Perinatal institute. Do you have diabetes?Things to do before you get pregnant. Available at: Birmingham, Perinatal institute, 2016. Available at: www.preg.info/PlanningAFamilyDiabetesNotes/PDF/2_planning_a_family_things_to_do.pdf
  8. NICE. Antenatal care for women with diabetes. Organisation of antenatal care and timetable of appointments. pathways.nice.org.uk/pathways/diabetes-in-pregnancy - path=view%3A/pathways/diabetes-in-pregnancy/antenatal-care-for-women-with-diabetes.xml&content=view-node%3Anodes-organisation-of-antenatal-care-and-timetable-of-appointments
  9. Stewart Z, Murphy H. Gestational diabetes. Medicine 2015; 43 (1): 44–47.
  10. NHS. The NHS Long Term Plan. NHS, 2019. Available at: www.longtermplan.nhs.uk/wp-content/uploads/2019/01/nhs-long-term-plan.pdf
  11. Perinatal Institute. Diabetes in pregnancy notes. Pages from the notes. www.preg.info/DiabetesInPregnancyNotes/Default.aspx (accessed 22 January 2019).
  12. Perinatal Institute. Pregnancy notes. View the pages. www.preg.info/PregnancyNotes/ViewThePages.aspx (accessed 25 February 2019).

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