Screening for Gestational Diabetes During Second Pregnancy May Not Be Necessary
Durham, N.C.--Women who do not test positive for gestational diabetes in their first pregnancy are unlikely to test positive during their second pregnancy if both pregnancies occur during a four-year time span, a new study from Duke University Medical Center shows.
"Obstetricians are taught to examine every pregnancy separately -- that one pregnancy cannot predict what will happen in the next," says Gerard Nahum, M.D., associate clinical professor of obstetrics and gynecology at Duke and lead author of the study. "This study shows that in the case of gestational diabetes, that might not be true. During a second pregnancy, we may be retesting women unnecessarily."
Sixty-nine women who had successive pregnancies delivered at intervals ranging from one to four years were given glucose screening tests at weeks 24 and 32 during both pregnancies. The study results showed that women testing negative for gestational diabetes during the first pregnancy had a less than 0.3 percent chance of acquiring gestational diabetes in the second pregnancy.
"We saw an 85 to 95 percent drop in the risk for diabetes in the second pregnancy if the mother tested negative during the first pregnancy," Nahum said.
"This study indicates that testing women a second time during a successive pregnancy may be unnecessary," according to Nahum. "With all the things women are screened for during pregnancy, we have to ask, 'is this one less thing that certain pregnant women need to worry about?'"
The study was published in the July 2002 Journal of Reproductive Medicine.
Gestational diabetes develops when a pregnant woman is not able to produce enough insulin to keep her blood sugar, also known as glucose, within a normal range that is safe for her and her developing baby. The problem affects 2 to 7 percent of all pregnant women in the United States.
Changes in diet and exercise are usually enough to help keep blood sugar levels within the normal range, but in some cases, insulin injections are needed. Most women who develop diabetes during pregnancy go back to having normal glucose tolerance after the birth of their baby; however, these women may be at greater risk for adult onset diabetes mellitus later in life.