A new scientific review found out that pregnant women having higher glucose levels were linked to experiencing increased risks of negative birth and maternal outcomes. This held true even for women who didn’t have gestational diabetes.
According to Dr. Diane Farrar, MD, from Bradford Institute for Health Research (U.K.), and her colleagues, pooled evidence pointed out a linear association present between increased levels of glucose and risk of pregnancy related problems such as preeclampsia, macrosomia, and shoulder dystocia. The review, published in The BMJ, noted that the results couldn’t highlight a certain threshold for glucose concentrations that would also relate to an increased risk in negative side effects for both mother and child.
Loralei Thornburg, MD, from the University of Rochester Medical Center in New York, also shared her opinion. She wasn’t part of the current research. However, she said that “The biggest thing this study adds to existing research is that glucose intolerance isn’t a ‘yes-no’ of having or not having diabetes. So, even with what is typically considered high normal testing (no gestational diabetes) patients were at higher risk for poor outcomes than someone with lower testing.”
The research found out that higher concentration of fasting glucose was associated strongly with the risk of negative outcomes for mother and child compared to the concentrations seen after a glucose test. The high levels of fasting glucose gave rise to a twofold increased risk of preeclampsia, large for gestational age infants, and macrosomia (or infants weighing more than 8 lbs, 13 oz). Increased levels of fasting glucose were also linked to negative prenatal outcomes such as shoulder dystocia and cesarean section.
According to the authors of the research an increase of 1 millimole per liter in fasting glucose gave rise to more than a twofold increased risk of a large for gestational age infant. However, a 1 mmol/L increase during the two hour post-load concentration was shown to only enhance the risk by 20%.
A total of 25 reports were examined by the researchers. These reports were from 23 published studies pertaining to high-income countries in North America, Australia, Asia, and Europe. But their analysis was not able to provide them with a definite glucose level threshold that gave rise to such negative outcomes.
During the study the researchers did make use of the International Association of Diabetes and Pregnancy criteria, also known as the IADPSG. The criteria defined the threshold for diagnosing gestational diabetes based on an odds ratio that is more than 1.75 for 3 outcomes: cord blood C peptide, skinfold thickness, and large for gestational age. However, according to researchers the current criteria didn’t follow a certain scientific system and mainly focused on obesity risk in the future and infant adiposity. The IADPSG criteria doesn’t cover important clinical outcomes such as neonatal hyperglycemia, need for induction, shoulder dystocia, cesarean section, etc. That is why further research is required.
The researchers recommend that until a definite glucose level threshold is found, patients suffering from impaired glucose tolerance or gestational diabetes should make changes in their lifestyle through proper diet and exercise. Pregnant women should also understand the risks that occur due to having high levels of glucose.