Is poor glucose control linked to multiple miscarriages in women who do not have diabetes?

This article examined if symptoms of diabetes were associated with multiple miscarriages in women who did not have diabetes. The authors found that high blood glucose levels and low insulin production were associated with multiple miscarriages.

Miscarriages can occur for many reasons. However, the cause of 50% of miscarriages is unknown.  Hyperglycemia (high glucose levels in the blood; HG) has previously been shown to cause stress in pregnancy, resulting in miscarriage. 

HG is caused by low levels of insulin, a hormone that lowers blood glucose to normal levels. Insulin is made in the pancreas by cells called beta-cells. If these cells do not function properly, not enough insulin is made, leading to HG. Insulin levels can be checked by measuring blood sugar levels after fasting (such as after sleep). Whether HG can cause miscarriages in women who do not have diabetes is unclear.

This study involved 160 women. 80 women had suffered multiple miscarriages in the first trimester (case group) and 80 women had had normal pregnancies (control group). Beta-cell function and blood glucose levels were measured in both groups.

Women who suffered from multiple miscarriages were significantly more likely to have beta-cells that did not function properly compared to the control group. 38.8% of the case group had dysfunctioning beta cells compared to 10% of the control group. The average beta-cell function was 264.41 in the case group and 447.82 in the control group. 

Women who suffered from multiple miscarriages were also more likely to have above-normal fasting glucose levels (over 5.1 mmol/L). Significantly more women in the case group had abnormal fasting glucose levels compared to the control group (27.5% vs. 6.3%). The average fasting blood glucose level was 4.77 mmol/L in the case group and 3.58 mmol/L in the control group. 

Other symptoms of HG were not significantly different in the case group. These included fasting insulin levels, insulin resistance, and insulin secretion.

The authors concluded that women who suffer from unexplained multiple miscarriages should have testing for beta-cell function and fasting blood glucose levels.

This study included women staying in the hospital, so these results may not reflect the general population. Patients' diets were not examined in this study, so genetic causes for miscarriages cannot be ruled out.

Talk to your doctor about testing for beta-cell function and fasting blood glucose levels.