Treating even mild forms of gestational diabetes helps cut the number of Cesarean sections.
Serious problems that can occur when women carry larger-than-average babies are treated when gestational diabetes is seen to, U.S. researchers said on Wednesday.
Although women are routinely treated for this kind of temporary diabetes, some doctors have wondered whether the benefits of treating slight diabetes symptoms outweigh any risks.
"The study confirms that it is worth the time and effort to treat women with even the mildest form of glucose intolerance during pregnancy," said Dr. Mark Landon of Ohio State University, whose study appears in the New England Journal of Medicine.
About 4 percent of all pregnant women in the United States develop gestational diabetes, a form of diabetes in which a pregnant women is unable to make and use all the insulin she needs for pregnancy. In most cases, the diabetes goes away after pregnancy.
Higher blood sugar levels can make babies larger and fatter than average, increasing the risk for Caesarean delivery or shoulder damage during birth and predisposing the child to diabetes and obesity.
Landon and colleagues studied 958 women at 15 medical centers, about half of whom were treated for mild gestational diabetes, which included a special diet, blood glucose monitoring and insulin shots if needed. The other half got routine prenatal care.
They found women who were treated were half as likely to have fat babies, and their babies were half as likely to have dislocated shoulders during delivery.
Treated women also had fewer Caesarean deliveries, with 26.9 percent of women in the treatment group having a Caesarean
birth, compared with 33.8 percent in the routine care group.
Treated women also had fewer problems with hypertension and preeclampsia, a potentially life-threatening condition marked by a sudden jump in blood pressure.
Mothers in the treatment arm also gained less weight during pregnancy and had fewer pre-term births.
"This study is important because it clearly indicates the value to mothers and their newborns of screening for and treatment of diabetes-like conditions provoked by pregnancy." Dr. John Thorp of the University of North Carolina at Chapel Hill, who worked on the study, said in a statement.
"Our work resolves a 40-year controversy in women's health and should be immediately helpful to both pregnant women and the clinicians caring for them."
In the United States there are about 135,000 cases of gestational diabetes each year.