Pregnancy

Pregnancy in women with diabetes carries risks for the mother and the unborn child. With good medical managment these risks can be substantially reduced. Educating all women of child bearing age with diabetes about these considerations in advance is a mandatory part of routine diabetes care.

What are the maternal risks of being pregnant with diabetes?

The maternal risks are:

1. Delivery of a macrosomic baby (obstructed labour, perineal injury, emergency caesarean section).

2. Worsening of diabetes complications, particularly retinopathy but also nephropathy

3. Hypoglycaemia. Frequent hypoglycaemia and hypoglycaemia unawareness are often encountered during pregnancy due to the lower glycaemia targets that pregnant women are encouraged to reach.

What are the foetal risks? 

The foetal risks are:

1. Increased malformation rates. 

2. Increased perinatal and neonatal mortality rates. 

3. Increased rates of early delivery. 

4. Increased rates of intra-uterine growth retardation.

5. Post-partum metabolic complications, principally hypoglycaemia.

How high are diabetic pregnancy complication rates?

In 1989, the St Vincent Declaration set out the reduction of diabetic pregnancy complication rates to near-background levels as a target.

However, this has not yet been achieved and although complication rates vary widely geographically and according to level of metabolic control it is widely recognised that diabetes pregnancy complication rates are still significantly above that in the non-diabetic population. For instance, UK data from the 1990s shows that background foetal malformation rates are in the region of 1-2% for all pregnancies and this can be up to four times higher in diabetic pregnancies. Similarly, perinatal mortality rates can be four times higher in diabetic pregnancies and neonatal mortality rates up to 15 times higher.

It is important to stress to the patient when counselling them that these risks can be significantly reduced by good glycaemic control during pregnancy and, in particular, during the peri-conception period.

What does standard pre-pregnancy counselling consist of?

When a women with diabetes attends for pre-pregnancy counselling the following areas should be covered:

1. There are increased risks associated with pregnancy as outlined under “What are the maternal risks of being pregnant with diabetes?” (see Q&A above) but these can be effectively managed - although not to background levels - by good glycaemic control. 

2. These risks can be significantly reduced by good metabolic control, especially important around conception and therefore attempts to conceive should ideally be delayed until an HbA1c in the region of 7% (53 mmol/mol) has been attained. However, good glycaemic control needs to be maintained throughout pregnancy.

3. Alcohol and cigarettes should not be consumed during pregnancy.

4. Five microgrammes of folic acid daily should be taken before conception and throughout the first trimester to reduce the risk of neural tube defects.

5. Blood glucose testing frequency needs to be increased to seven times per day (before and after each meal and pre-bed).

6. Targets for glycaemia should be 4-6 pre-prandially and 6-8 one hour post prandial.

7. Metformin can be continued throughout pregnancy but all other oral hypoglycaemics should be stopped prior to conception.

8. Insulin can be continued throughout pregnancy but there is slight reticence about use of long acting insulin analogues during pregnancy and the default position should be an NPH medium acting insulin such as Humulin I in preference to insulin glargine or insulin determir. However, some women will experience an increased rate of hypoglycaemia with NPH insulin and in this situation the small and un-proven risk of insulin analogues in pregnancy should be discussed with the patient and balanced against the risks of hypoglycaemia before a decision is made.

9. Statins and ACE inhibitors should be withdrawn prior to conception.

10. The potential risk of worsening of retinopathy should be discussed and recent retinal screening photos should be reviewed.

11. An ACR and eGFR should be assessed prior to conception, women with significant nephropathy should be counselled that although not an absolute contraindication to pregnancy, nephropathy will add additional risk to a pregnancy and the nephrologists should be involved early in the pregnancy.

12. She should also be offered appointments with a diabetes nurse specialist with an interest in diabetes in pregnancy and should be offered a dietetic appointment.

What advice should be given to all women with diabetes regarding pregnancy?  

From teenage years onwards, a brief discussion of pregnancy plans and contraception should be a routine part of all diabetes consultations with women.

The single most important topic to cover is arguably the importance of avoiding unplanned pregnancy. Thus the importance of effective contraception should be emphasised. The desirability of planning pregnancy and the importance of seeking medical advice prior to conception should also be re-emphasised at each visit in the hope that this will lessen the risk of an unplanned pregnancy.

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