A new study by Dr. Ivan Ngai and colleagues from the Albert Einstein College of Medicine and Montefiore Medical Center in New York City suggests that women who are diagnosed with gestational diabetes before 6 months (24 weeks) of pregnancy have a greatly increased risk of a preterm delivery compared to those diagnosed after 24 weeks. The study was presented at the annual meeting of the American College of Obstetricians and Gynecologists (ACOG).
The researchers examined the medical records of 708 pregnant women 305 were diagnosed with gestational diabetes before 24 weeks and 401 were diagnosed after that time. The women had been tested for gestational diabetes at their first prenatal visit. If they were not diabetic at this visit, they were not tested again until 24 weeks.
Dr. Ngai told MedPage Today there was an over 10-fold increase in preterm deliveries (earlier than 37 weeks of pregnancy) in the women who were diagnosed before 6 months compared to those diagnosed after that time. Further, they found that women who were diagnosed earlier were also significantly more likely to have a greater BMI, and have significantly smaller babies.
Dr. Ngai reported that current ACOG guidelines call for testing for diabetes after 6 months of pregnancy, but considering the results of this study, suggested that in populations with a high prevalence of diabetes such testing should be considered earlier during a woman s pregnancy.
ACSH s Dr. Gilbert Ross commented, Since this is a preliminary, retrospective study, it must be confirmed with prospective studies before it is considered valid, although its large size and impressive relative risks lend credibility. Also one cannot assume from this that the early occurrence of gestational diabetes is what caused preterm birth. However, if these results are independently replicated, they would provide a valid rationale for changing the ACOG guidelines, at least in populations in which gestational diabetes is prevalent.