Depression in early pregnancy linked to gestational diabetes

The study was published online in Diabetologia.

Gestational diabetes is a form of diabetes (high blood sugar level) occurring only in pregnancy, which if untreated may cause serious health problems for mother and infant.

"Our data suggest that depression and gestational diabetes may occur together," said the study's first author, Stefanie Hinkle, Ph.D., staff scientist in the Division of Intramural Population Health Research at the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). "Until we learn more, physicians may want to consider observing pregnant women with depressive symptoms for signs of gestational diabetes. They also may want to monitor women who have had gestational diabetes for signs of postpartum depression."

Although obesity is known to increase the risk for gestational diabetes, the likelihood of gestational diabetes was higher for non-obese women reporting depression than for obese women with depression.

The researchers analyzed pregnancy records from the NICHD Fetal Growth Studies-Singleton Cohort, which tracked the progress of thousands of pregnancies, to understand the patterns of fetal growth. The study enrolled 2,334 non-obese and 468 obese women in weeks eight to 13 of pregnancy. The women responded to questionnaires on symptoms of depression when they enrolled in the study, again between the 16^th and 22^nd week of pregnancy, and then six weeks after giving birth. The researchers also reviewed the women's records to identify who had developed gestational diabetes.

"Of particular note, persistent depression from the first to second trimester set women at even greater risk for gestational diabetes" said the study's senior author, Cuilin Zhang, M.D., Ph.D, in the Division of Intramural Population Health Research at NICHD. Women who had the highest scores for depression in the first and second trimesters -- about 17 percent -- had nearly triple the risk for gestational diabetes when compared to women who had lower depression scores.

"Our results suggest it would be a good idea for clinicians to pay particular attention to women with high depression scores when evaluating the risk of gestational diabetes," Dr. Zhang added.

Although obesity increases the risk for gestational diabetes, non-obese women with high depression scores had nearly triple the risk for gestational diabetes than the other women in the study. Depression did not appear to increase the risk for gestational diabetes among obese women.

Currently, the American College of Obstetricians and Gynecologists recommends that physicians screen patients at least once for depression during the perinatal period (22 weeks of pregnancy through 7 days after birth.)

The researchers also found a higher risk for postpartum depression among the women who had gestational diabetes. Of the women who developed gestational diabetes, nearly 15 percent experienced depressive symptoms after birth, which was more than four times that of women who had not had gestational diabetes.

Dr. Hinkle stressed that the study was not able to prove a cause and effect relationship between symptoms of depression and gestational diabetes. The researchers added that earlier studies have shown that depression is associated with impaired glucose metabolism that may lead to higher blood sugar levels. Similarly, high blood sugar levels may lead to inflammation, hormonal, and other changes that could lead to symptoms of depression.