• Posted April 17, 2024

Placenta Plays Role in Gestational Diabetes, Study Suggests

The placenta could be one reason why some women develop gestational diabetes during pregnancy, a new study finds.

A deficit in the way the placenta expresses the gene for a hormone called insulin-like growth factor 1 (IGF-1) appears linked to insulin resistance during pregnancy, researchers reported April 16 in the journal Nature Medicine.

"The placenta -- the major driver of changes in insulin physiology in pregnancy -- is likely a key source of hormones involved in the development of gestational diabetes,"said lead researcher Marie-France Hivert, an associate professor of population medicine at Harvard Medical School.

Gestational diabetes affects one in seven pregnancies, and can lead to multiple complications during pregnancy and delivery.

Excess insulin resistance contributes to gestational diabetes, prior research has found, but the exact causes of this resistance remains unclear.

For this study, researchers conducted genetic analysis on placental tissue samples, identifying 14 genes associated with insulin resistance.

The strongest association involved the IGF-1 gene, which manages the effects of growth hormone in the body, results show. The hormone produced by the IGF-1 gene is related to the insulin hormone and affects how cells process blood sugar.

IGF-1 hormone levels rise over the course of pregnancy and are five times higher in pregnant people, the researchers noted.

Further, low levels of IGF-1 hormone in early pregnancy could be an indicator that a woman is at risk for gestational diabetes, given that higher levels are associated with less insulin resistance, researchers said. 

In fact, low blood levels of IGF-1 hormone in the first trimester appear to predict later diagnosis of gestational diabetes, independent of other risk factors like excess weight, results show.

"It's possible that measuring [IGF-1 hormone] in the first trimester could help identify people at risk of developing gestational diabetes early in pregnancy, potentially offering a window for prevention,"Hivert said in a Harvard news release. "We hope to conduct future research to address whether this protein plays a causal role in gestational glycemic regulation."

More information

The U.S. Centers for Disease Control and Prevention has more on gestational diabetes.

SOURCE: Harvard Pilgrim Health Care Institute, news release, April 16, 2024