A common complication of gestational diabetes, the overgrowth of the baby begins weeks before women are tested for the disease, according to new research from South Korea.
Researchers analyzed 8,000 singleton pregnancies and found that in women subsequently diagnosed with gestational diabetes, abdominal fetal growth was already abnormally large between 20 and 24 weeks — more than 4 weeks before the recommended screening time.
Even among women without diabetes, the babies of mothers who were older or obese were at far greater risk of being abnormally large in abdominal circumference at the 22-week scan, but not in younger and non-obese women.
Given the high risk of complications for both mother and baby from maternal diabetes, screening women earlier on in pregnancy is likely to improve their health outcomes, researchers say.
“Abdominal overgrowth of the baby in the womb is believed to indicate fetal obesity, not just a big baby,” explains Dr. Yoo Lee Kim from CHA University, the Republic of Korea who led the research.
“Our findings suggest that diagnosing gestational diabetes and implementing interventions to reduce the risk of excessive fetal growth such as diet and exercise earlier in pregnancy may be necessary to prevent harm to mothers and their babies,” Kim added.
What is Gestational Diabetes?
Gestational diabetes is a temporary form of diabetes in which hormonal changes disrupt insulin function, affects 3-20% of pregnant women, with those who are obese and/or older at greater risk.
Women who develop gestational diabetes are seven times as likely to develop Type 2 diabetes in the years following pregnancy.
If left undiagnosed and untreated, the condition can also cause the unborn child to have increased birth weight, higher body fat, and lower insulin sensitivity, and increases the likelihood of obesity and diabetes in later life.
Current guidelines in South Korea, the UK, and the USA recommend that all pregnant women are screened for gestational diabetes using an oral glucose test at 24-28 weeks of pregnancy.
However, previous research suggests that excessive fetal growth can already be detected at the time of screening (24-28 weeks), especially in older women and those with obesity.
Whether the onset of this fetal growth disorder predates the recommended screening time is unclear.
“Early screening and careful monitoring may be particularly beneficial for obese and older mothers, as fetal abdominal growth is already abnormal at 5 months in these high-risk women, meaning that their babies are already large at the time of diagnosis,” Kim concluded.
Because the study was purely observational, no firm conclusions can be drawn about cause and effect, and the authors point to several limitations including that the study was done in a single center.
Additionally, they could not determine exactly why the fetuses of women with gestational diabetes were larger than foetuses in the non-diabetic group.
The study is being presented at this year’s European Association for the Study of Diabetes (EASD) Annual Meeting in Barcelona, Spain (16-20 September).
- Diabetologia. (2019, September 16). Overgrowth of baby in womb may begin weeks before women are tested for maternal diabetes. ScienceDaily. Retrieved September 17, 2019, from www.sciencedaily.com/releases/2019/09/190916185815.htm