Estimates vary as to its prevalence, but according to the Center for Vulnerable Populations at San Francisco General Hospital and Trauma Center, gestational diabetes affected somewhere between 7-18% of pregnancies in the US in 2013.
The condition can affect the mother’s health and cause excessive growth in the unborn child. The Centers for Disease Control and Prevention (CDC) explain that when the baby’s blood sugar is too high, the baby becomes “overfed,” leading to extra growth.
This increases the risk to the mother when giving birth, and the child is more likely to develop obesity and diabetes later in life.
Control of gestational diabetes is normally possible through diet and exercise; if not, medication is available.
At 8-12 weeks of pregnancy, women are screened for gestational diabetes through a blood glucose test, and, according to current guidelines in the US and the UK, those at greatest risk can have a full test at 24-28 weeks. In reality, most women attend screening at 28 weeks.
Five-fold increase in chance of fetal overgrowth
Researchers from the Department of Obstetrics & Gynecology at the University of Cambridge in the UK analyzed data for over 4,000 first-time mothers.
The mothers were part of the Pregnancy Outcome Prediction study, which used ultrasound scans to collect data on abdominal and head circumference, in order to assess fetal growth.
Researchers compared the growth of babies whose mothers had gestational diabetes with those whose mothers did not.
At or after 28 weeks, 4.2% of mothers received a diagnosis of gestational diabetes.
At 20 weeks, there was no link between the size of the child and a later emergence of gestational diabetes.
However, from 20-28 weeks, there was excessive growth among fetuses of women who were later found to have gestational diabetes. In other words, by the time diagnosis took place, at 28 weeks, the babies were already large.