Preconception Care for Women With Diabetes: A Review of Current Guidelines
Of the five guidelines identified, two were from the American Diabetes Association (ADA) (ADA 2009 and ADA 2004). The ADA 2009 is the generic guideline for medical care in diabetes with a specific chapter on pre-conception care, whereas the ADA 2004 guideline is focussed on preconception care of women with diabetes. The remaining guidelines were produced by the National Institute for Health and Clinical Excellence (NICE) (NICE 2008), the Scottish Intercollegiate Guideline Network (SIGN) (SIGN 2001), and the Australasian Diabetes in Pregnancy Society (ADIPS) (ADIPS 2005).
All guidelines were rated as being of high quality and strongly recommended for use in practice using the AGREE instrument. Scores for individual guidelines using the AGREE instrument are given in Table 2.
Management Approach and Evaluation of Previous Medical and Obstetric History All the practice guidelines agree that diabetic women contemplating pregnancy should be seen by a multidisciplinary team; however this was not specifically mentioned by the NICE guidelines. Both the ADA 2009 and the SIGN guidelines recommend undertaking a complete preconception evaluation of the women's medical and obstetric history.
Evaluation and Treatment of Diabetic Complications Evaluating and treating diabetic retinopathy is recommended by all the guidelines and nephropathy by all except SIGN. The ADA and ADIPS guidelines also recommend an assessment of neuropathy and undertaking a cardiovascular assessment prior to conception.
Specifically assessing the women for hypertension is only recommended by ADA 2004 and SIGN with the latter nominating a target blood pressure (BP) of < 140/80 for women with diabetic nephropathy.
Review of Current Medication Undertaking a medication review before a diabetic woman gets pregnant is recommended by all the guidelines except NICE. While stopping Angiotensin-Converting Enzyme (ACE) inhibitors is mentioned by all, some guidelines also recommend stopping statins and angiotensin-II receptor antagonists (ARB). The ADA 2004 also recommends stopping diuretics and β-blockers.
Assessment of Metabolic Control and Blood Glucose Management Monitoring metabolic control using HbA1C and achieving a target of < 7% is recommended by all guidelines. NICE however, sets a lower target of < 6.1%. Blood glucose self monitoring is another important recommendation by most of the guidelines apart from ADA 2009 or the ADIPS 2005 guidelines. The ADA 2004 defines a target pre-meal blood glucose level of between 4.4–6.1 mmol/L and 2 hours after meals < 8.6 mmol/L. All guidelines, except for the ADA 2009, confirm that blood sugar levels should be maintained as normal as possible whilst avoiding hypoglycaemia. Both the NICE and ADIPS guidelines advocate teaching the patient and partner about hypoglycaemia awareness and management.
All guidelines recommend prescribing insulin preconceptionally to achieve target levels of blood glucose. Use of metformin as an adjunct or alternative for diabetic treatment preconceptionally when insulin treatment is refused or a patient develops resistance, is recommended by the more recent guidelines.
Folate Supplementation Folate supplementation with a daily dose of 5 mg is recommended by three of the guidelines for those planning to become pregnant up until 12 weeks gestation. ADIPS does not mention the duration of treatment. Both ADA 2009 and ADA 2004 fail to mention the importance of folate supplementation.
Preconception Counselling The routine incorporation of preconception counselling into diabetic clinic visits for all women of child-bearing potential is recommended by ADA 2009. All guidelines recommend that diabetic women should receive counselling about the effective use of contraception in order to plan pregnancies, and the risk of malformation with poor metabolic control and unplanned pregnancy. Informing the patient about how Diabetes Mellitus (DM) affects pregnancy and how pregnancy affects DM is recommended by two guidelines. Other important preconception issues like smoking cessation and reducing alcohol intake is only recommended by ADIPS 2005. ADIPS recommends weight management and exercise as general pre-pregnancy advice and NICE recommends weight reduction for women with a BMI >27 kg/m. Provision of dietary advice such as consuming a diet with high levels of complex carbohydrates, soluble fibre and vitamins, and reduced levels of saturated fats is also recommended.
Contraindications to Pregnancy The NICE guideline states that an HbA1C > 10% is a contraindication to pregnancy. In contrast ADIPS suggests that impaired renal function as measured by a serum creatinine > 0.2 mmol/L should be a contraindication to pregnancy.
Thyroid Screening Thyroid function screening is recommended by ADA 2004 and ADIPS for women with Type 1 diabetes but not T2DM.
A summary of preconception care recommendations for diabetic women is provided in Table 3.
Results
Of the five guidelines identified, two were from the American Diabetes Association (ADA) (ADA 2009 and ADA 2004). The ADA 2009 is the generic guideline for medical care in diabetes with a specific chapter on pre-conception care, whereas the ADA 2004 guideline is focussed on preconception care of women with diabetes. The remaining guidelines were produced by the National Institute for Health and Clinical Excellence (NICE) (NICE 2008), the Scottish Intercollegiate Guideline Network (SIGN) (SIGN 2001), and the Australasian Diabetes in Pregnancy Society (ADIPS) (ADIPS 2005).
Comparison of Guideline Quality
All guidelines were rated as being of high quality and strongly recommended for use in practice using the AGREE instrument. Scores for individual guidelines using the AGREE instrument are given in Table 2.
Comparison of Guideline Recommendations
Management Approach and Evaluation of Previous Medical and Obstetric History All the practice guidelines agree that diabetic women contemplating pregnancy should be seen by a multidisciplinary team; however this was not specifically mentioned by the NICE guidelines. Both the ADA 2009 and the SIGN guidelines recommend undertaking a complete preconception evaluation of the women's medical and obstetric history.
Evaluation and Treatment of Diabetic Complications Evaluating and treating diabetic retinopathy is recommended by all the guidelines and nephropathy by all except SIGN. The ADA and ADIPS guidelines also recommend an assessment of neuropathy and undertaking a cardiovascular assessment prior to conception.
Specifically assessing the women for hypertension is only recommended by ADA 2004 and SIGN with the latter nominating a target blood pressure (BP) of < 140/80 for women with diabetic nephropathy.
Review of Current Medication Undertaking a medication review before a diabetic woman gets pregnant is recommended by all the guidelines except NICE. While stopping Angiotensin-Converting Enzyme (ACE) inhibitors is mentioned by all, some guidelines also recommend stopping statins and angiotensin-II receptor antagonists (ARB). The ADA 2004 also recommends stopping diuretics and β-blockers.
Assessment of Metabolic Control and Blood Glucose Management Monitoring metabolic control using HbA1C and achieving a target of < 7% is recommended by all guidelines. NICE however, sets a lower target of < 6.1%. Blood glucose self monitoring is another important recommendation by most of the guidelines apart from ADA 2009 or the ADIPS 2005 guidelines. The ADA 2004 defines a target pre-meal blood glucose level of between 4.4–6.1 mmol/L and 2 hours after meals < 8.6 mmol/L. All guidelines, except for the ADA 2009, confirm that blood sugar levels should be maintained as normal as possible whilst avoiding hypoglycaemia. Both the NICE and ADIPS guidelines advocate teaching the patient and partner about hypoglycaemia awareness and management.
All guidelines recommend prescribing insulin preconceptionally to achieve target levels of blood glucose. Use of metformin as an adjunct or alternative for diabetic treatment preconceptionally when insulin treatment is refused or a patient develops resistance, is recommended by the more recent guidelines.
Folate Supplementation Folate supplementation with a daily dose of 5 mg is recommended by three of the guidelines for those planning to become pregnant up until 12 weeks gestation. ADIPS does not mention the duration of treatment. Both ADA 2009 and ADA 2004 fail to mention the importance of folate supplementation.
Preconception Counselling The routine incorporation of preconception counselling into diabetic clinic visits for all women of child-bearing potential is recommended by ADA 2009. All guidelines recommend that diabetic women should receive counselling about the effective use of contraception in order to plan pregnancies, and the risk of malformation with poor metabolic control and unplanned pregnancy. Informing the patient about how Diabetes Mellitus (DM) affects pregnancy and how pregnancy affects DM is recommended by two guidelines. Other important preconception issues like smoking cessation and reducing alcohol intake is only recommended by ADIPS 2005. ADIPS recommends weight management and exercise as general pre-pregnancy advice and NICE recommends weight reduction for women with a BMI >27 kg/m. Provision of dietary advice such as consuming a diet with high levels of complex carbohydrates, soluble fibre and vitamins, and reduced levels of saturated fats is also recommended.
Contraindications to Pregnancy The NICE guideline states that an HbA1C > 10% is a contraindication to pregnancy. In contrast ADIPS suggests that impaired renal function as measured by a serum creatinine > 0.2 mmol/L should be a contraindication to pregnancy.
Thyroid Screening Thyroid function screening is recommended by ADA 2004 and ADIPS for women with Type 1 diabetes but not T2DM.
A summary of preconception care recommendations for diabetic women is provided in Table 3.
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