Eating for Two

Response of unborn children to glucose associated with mother's insulin sensitivity

In this new study, Preissl and colleagues aimed to show that the metabolism of a pregnant woman, following a meal, influences fetal brain activity. A total of 13 healthy pregnant women underwent an oral glucose tolerance test (75 g of glucose delivered orally, a standard method for determining insulin sensitivity). Insulin sensitivity was determined by glucose and insulin measurements at 0, 60 and 120 min. At each time point, the response of the fetus was examined by recording fetal brain responses elicited by sounds with a magnetoencephalographic device.

The researchers found that after 60 minutes, women who were more insulin resistant had fetuses that reacted more slowly to the sound test. When divided into two groups based on insulin sensitivity, the insulin-resistant mothers had fetuses that reacted to the sound at an average of 283 milliseconds, compared with 178 ms for the insulin-sensitive group.

They suggest that the findings support a hypothesis first made almost 50 years ago (1967) by scientist Jørgen Pedersen. The authors say: "It is possible that insulin-resistant mothers have higher glucose levels accompanied by increased insulin levels after a meal. As glucose passes the placenta, these increased glucose levels induce excess insulin (hyperinsulinaemeia) in the fetus. Therefore, high insulin levels in the mother may correspond to high insulin levels in the fetus."