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Ten Things You Need to Know Before You Get Pregnant if You Have Diabetes

Given the importance of good blood sugar control during pregnancy, it is bewildering that the 2015 NICE guidelines doadvise that diabetic women should be routinely offered a continuous glucose monitor for the duration of their pregnancy.

1. Pregnancy can be a challenge for any woman, but for women suffering from diabetes, it presents a very particular set of problems. There are two different forms of diabetes; Type 1, which is relatively rare, and Type 2 which accounts for 90% of all diabetes. Both forms of diabetes interfere with the bodies ability to regulate blood sugar levels and this can cause serious complications for women who want to have children.

2. High blood sugars quadruple the risk of birth defects, so it is essential for women with diabetes to have good blood sugar control for at least three months before they get pregnant. Despite the need for careful pre-pregnancy diabetes planning, the Confidential Enquiry into Maternal and Child Health Diabetes Programme (CEMACH) which was set up to provide an overview of diabetes maternity services, national pregnancy outcome rates and standards of care, found that between 2002 and 2003, fewer than half (41%) of women with diabetes studied in the enquiry had planned their pregnancy. This compared to a planned pregnancy rate of 58% in the general maternity population in 2001-02.

3. Evidence for the positive impact of good glucose control on perinatal outcome has been available since the 1980s, but the CEMACH enquiry also found that the majority of diabetic women entered pregnancy with poor blood sugar control.

4. Women suffering from diabetes are advised to have regular HbA1c testing prior to getting pregnant in order to reduce the risk of adverse outcomes. HbA1c testing measures the amount of glucose-bound haemoglobin and reflects how well blood sugar levels have been controlled over the previous 120 days.

5. In the CEMACH enquiry, 72% of pregnant diabetics had been given a documented HbA1c test by 13 weeks of gestation, but only 38% had managed to achieve blood sugar levels within the recommended HbA1c range of less than 7%. Even so, one quarter of the babies born to mothers who achieved a level of 7% in the first trimester were still born with a congenital anomaly.

6. Experts now believe that a HbA1c figure of 6.1% should be the target. In a cohort study of 401,000 pregnancies that occurred between 1996 and 2008, which was carried out by researchers from Newcastle University, it was found that each increase of 1% in HbA1c over 6.3% was associated with a 30% increase in the odds of birth defects.

7. The HbA1c test is helpful but it is not an entirely accurate measure. If women have had lots of low blood sugar readings in the three months prior to testing, levels of glucose-bound haemoglobin will be lower and this can give a woman and her doctor a false sense of security.

8. Continuous glucose monitoring provides a much better indication of day to day blood sugar fluctuations for people with diabetes. Sensors which are attached to the skin measure the glucose levels in the interstitial fluid - the fluid in and around your body's cells, and provide a continuous reading of changing sugar levels. Although they have to be calibrated with finger prick blood glucose tests, the monitors alarm when blood sugar gets too low ,or too high, and because they show the general direction of travel for blood sugars, users can treat potential problems more efficiently.

9. Continuous glucose monitoring provides a much more detailed and comprehensive picture of overall control and most importantly, it can pick up fluctuations in blood sugar levels that occur during sleep. In three day trials of continuous glucose monitors, research by Boland et al (2001) found that most of their diabetes patients had experienced at least one serious blood sugar anomaly that would not have been picked up by normal glucose meter readings or HbA1c. Research by Helen R Murphy at Ipswich hospital has also shown that continuous glucose monitoring during pregnancy is associated with improved glycaemic control in the third trimester and reduced risk of complications for the baby.

10. Given the importance of good blood sugar control during pregnancy, it is bewildering that the 2015 NICE guidelines do not advise that diabetic women should be routinely offered a continuous glucose monitor for the duration of their pregnancy. While sympathetic to the budgetry constraints facing the NHS, it is a false economy to deny pregnant diabetics access to technologies which could make the difference between them giving birth to a healthy baby, or one that needs long term NHS care. Or a funeral.