Women diagnosed with Gestational Diabetes (GDM) often give birth to babies that are larger than average. This is because the baby is exposed to higher levels of glucose as a fetus and as a result they secrete higher levels of insulin, causing excessive growth. Women diagnosed with GDM have an increased risk of certain complications, some of which are caused by this excessive growth (birth trauma, difficulty delivering the baby’s shoulder, vaginal and anal injury) and some that have a less obvious cause (pregnancy-related high blood pressure, Cesarean section due to fetal distress, death of the baby before delivery). These latter complications have a well-known association with fetal growth restriction (defined as a fetus with an estimated weight that is below the 10th percentile for it’s gestational age). This means that some fetuses of women diagnosed with GDM show growth restriction despite not being small for gestational age. In other words, it is possible that these babies are not meeting their growth potential, but they are not diagnosed with fetal growth restriction because of the glucose driven excessive growth. The objective of this study is to examine whether a Doppler ultrasound exam can identify fetuses that are not growth restricted but are at increased risk of certain adverse neonatal outcomes in women diagnosed with GDM.

This is an observational prospective study and does not involve any drug or treatment interventions. The study is looking to recruit pregnant women over the age of 18 years old, with a singleton pregnancy and a diagnosis of GDM at 24 weeks of gestation and beyond.  If you have pre-gestational diabetes or high blood pressure at time of recruitment, a fetus with a known major problem, or fetal estimated weight < 10% we will not be able to include you in the study.

If you are eligible and chose to participate in the study, you will be asked to undergo a fetal Doppler ultrasound after each of your regularly planned fetal ultrasound examinations. An ultrasound exam is done every 2-4 weeks, usually from 26 weeks of the pregnancy, until the delivery, and is a part of your routine care at the diabetes in pregnancy (DIP) clinic. The Doppler will be added to each ultrasound you will have in DIP clinic and will take approximately 5 minutes to complete. The Doppler is not carried out routinely at the DIP clinic. However, in cases where the fetal growth is lower than 10% based on the results of the measurements in ultrasound, a Doppler is then added as a part of routine care.

Both the ultrasound and Doppler examinations will be performed on your abdomen. The ultrasound examination will look at standard measures such as growth and wellbeing of your baby (monitoring your baby’s movements as well as the amniotic fluid). The Doppler examination will look at the blood-flow in the fetal umbilical artery and in an artery supplying blood to the brain -the middle cerebral artery. The Doppler will not pose additional risk for you or for the baby.

Study Contact
Negar Bagheri (negar.bagheri@unityhealth.to)