A recent newspaper story from the UK reported that a British study has concluded that the risk of birth defects increases four-fold if the pregnant mother has diabetes. The authors of the study found that "the rate of non-chromosomal major congenital anomaly in women with diabetes was 71.6 per 1,000 pregnancies..., a relative risk of 3.8 ... compared with [19.1 per 1000 pregnancies in] women without diabetes" and concluded that "peri-conception glycaemia is the most important modifiable risk factor for congenital anomaly in women with diabetes."
I wasn't surprised at either point: it's been known for generations that pregnancy in women with diabetes has had an increased risk of bad outcomes, including miscarriage, macrosomia -- also known as big baby syndrome, and congenital anomalies. And it's been known that tight control of glucose control before conception makes a difference in these outcomes. The two major factors that the authors found that make a difference are blood sugar control around the time of conception, and the presence of kidney disease. Also, risk of anomaly was higher for women from what they term "deprived areas" or those who did not take folate acid supplementation. They found that "type and duration of diabetes, ethnicity, age, BMI, preconception care, smoking and fetal sex were not associated with congenital anomaly risk."
Diabetes UK, the British diabetes association, helped fund the study and issued a press release that quoted the lead researcher: "The good news is that, with expert help before and during pregnancy, most women with diabetes will have a healthy baby. The risk of problems can be reduced by taking extra care to have the best possible glucose control before becoming pregnant. Any reduction in high glucose levels is likely to improve the chances of a healthy baby."
I've discussed previously that there are very specific steps a woman with diabetes should take when she is planning a pregnancy. These include tightening up her blood glucose targets; checking glucose levels more frequently, weekly communication with the diabetes care team; plan to go onto MDI (multiple daily insulin injections) or an insulin pump; start folic acid supplementation; stop smoking; and many more. See Planning a Pregnancy with Diabetes for the complete list.
If you are a young woman with diabetes who will be planning a pregnancy, or if you know someone who fits this description, this recent study again emphasizes the point that it's important to get your diabetes under control before pregnancy. It'll improve the odds of having a successful pregnancy.