Pregnancy - key issues

Pre-pregnancy care for women with diabetes

The role of pre-pregnancy care is to ensure that the woman has good blood glucose control, understands the need for folic acid supplements, is informed of dietary requirements and is screened for evidence of complications particularly retinopathy. A renal assessment is also recommended. Pre-pregnancy care should also address the various problems that can be encountered during pregnancy. These include:

  • Microvascular and macrovascular disease.
  • Renal disease and hypertension and the treatment of which can be associated with intrauterine growth retardation.
  • Renal function can irreversibly decline significantly after pregnancy.
  • Retinopathy can deteriorate significantly during pregnancy.
  • Angiotensin-converting enzyme inhibitors (ACEI) are contraindicated to control elevated blood pressure in pregnancy.
  • Autonomic neuropathy can be associated with intractable vomiting.
  • Severe ischaemic heart disease can cause maternal death.
  • Women who have Type 2 diabetes and require oral hypoglycaemics will need to transfer to insulin during pregnancy.

The role of the pre-pregnancy clinic is to review medical, obstetric and gynaecological history; advise on glycaemic control to optimise HbA1c prior to conception and to screen for and manage complications.

More information on pre-conception care can be found on the Diabetes UK website: Diabetes UK: Preconception care for women with diabetes.

Ketoacidosis

Ketoacidosis is a preventable condition caused by protracted elevated blood glucose levels. The foetus is very sensitive to ketoacidosis and can die as a result of this at any stage in pregnancy. All pregnant women with diabetes should be instructed to test for ketones if their blood glucose is high, if they are vomiting for any reason or if they are unwell. Immediate advice should be obtained if ketones are found. NICE guidance recommends admission to hospital for level two critical care with availability of both medical and obstetric care if diabetic ketoacidosis is suspected during pregnancy (National Institute for Health and Clinical Excellence 2008b).

Guidance has been published by the Joint British Diabetes Societies on the management of diabetic ketoacidosis in adults which reflects recent developments and which is particularly aimed at care and management in the hospital setting. This includes a number of references to care in pregnancy. The guidance is accompanied by a care pathway. Both documents are made available on the Diabetes UK website – see Care recommendations: the management of diabetic ketoacidosis in adults.

Vomiting

All women should be instructed in how to cope with vomiting as severe nausea and vomiting can lead to ketoacidosis. Women with severe nausea of pregnancy should be treated with an antiemetic and those with severe vomiting hospitalised promptly. The NHS Clinical Knowledge Summaries (CKS) website brings together evidence-based information and practical 'know-how' about common conditions managed in primary care and has a section on Management of nausea and vomiting in pregnancy.

Insulin

Insulin may need to be adjusted during pregnancy. The blood glucose ‘target’ if safely achievable is a fasting blood glucose between 3.5 and 5.9 mmol/litre and below 7.8 mmol/litre one hour after eating (National Institute for Health and Clinical Excellence 2008b).

Congenital malformations

Research described by the Confidential Enquiry into Maternal and Child Health (CEMACH) showed  the prevalence of confirmed major congenital anomalies as being 41.8 per 1000 births (live and still) for  babies of mothers with diabetes compared with 21 per 1000 births for babies of mothers in general (CEMACH 2005).  There are specific areas of concern such as neural tube defects, caudal regression syndrome and interventricular hypertrophic cardiomyopathy.

One of the aims of the National Service Framework for diabetes (Department of Health 2001b) is to reduce the incidents of anomalies and outcomes for mothers who have diabetes to the same levels as that of mothers who do not have diabetes.

Some studies have shown that good glycaemic control at the time of conception can reduce the incidence of congenital anomalies. However, this level of control can only be achieved if preconception advice and management is instituted. Attendance at a pre-pregnancy clinic is also associated with a reduction in the rate of spontaneous abortion and in complications of diabetes.

Nutritional management

It is good clinical practice for a woman with diabetes to see a registered dietician for dietary advice before, during and after pregnancy. Dietetic advice is also available for women with gestational diabetes. The main recommendations are for low GI index carbohydrate meals to be evenly spaced throughout the day. Advice regarding fat, salt, shellfish, alcohol and some soft cheeses is the same as for pregnant women who do not have diabetes.

Folic acid supplementation

For information, go to the Diabetes UK website: Diabetes UK care recommendations on folic acid supplementation in pregnancy.

Nephropathy

The prevalence of diabetic nephropathy in pregnant women with Type 1 diabetes is estimated at 6%. There is an association between pre-existing nephropathy (microalbuminuria or albuminuria) and a poorer pregnancy outcome, though this is not due to any increase in congenital malformations. Worsening nephropathy and superimposed pre-eclampsia are the most common causes of pre-term delivery in women with diabetes.

An overnight urine collection or spot urine for albumin:creatinine ratio (ACR) should be measured in all women to identify their renal status prior to pregnancy. Angiotensin converting enzyme inhibitors (ACEIs) are contraindicated during pregnancy as they may adversely affect the fetus, causing renal agenesis. One study has shown that the ACEI, captopril given to patients with diabetic nephropathy (proteinuria > (more than) 500mg/day) before and up to conception may have a prolonged protective effect on maternal renal function during pregnancy and results in a favourable maternal-fetal outcome. Target blood pressure should be < (less than) 140/80 and appropriate antihypertensive agents which may be used during pregnancy include methyldopa, labetalol and experience is accumulating with nifedipine and diltiazem. The indication for these drugs will be made by a consultant experienced in diabetes and maternal care.

Additional assessments:

  • Thyroid function and thyroid antibodies should be checked.
  • Rubella antibodies should be measured.

References

Full details of the bracketed citations in the text above and, in many cases, links to the actual documents are available in the reference list within this resource. Go to the Reference list.

For more information, go to: pregnancy.