Women’s health | Effectively managing gestational diabetes with CGM

What is gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is hyperglycaemia that results in a type of diabetes that affects pregnant women. It accounts for 90% of diabetes during pregnancy. It usually resolves after the birth. Although can still have negative long term health consequences for the mother and baby such as: susceptibility to obesity, metabolic syndrome and diabetes later on. (1)  It may also lead to “maternal and perinatal outcomes such as pregnancy-induced hypertension, pre-eclampsia, antepartum haemorrhage, caesarean, preterm birth, birth trauma and congenital anomalies”. (1) 

What are the causes?

Research shows that women are more at risk of GDM when they are overweight and/or obese, have a family history of type 2 diabetes, had a previous stillbirth, macrosomic child, and are aged over 30. Due to the fact that overweight and/or obese women are more at risk, GDM is also more frequent in urban areas, often as a result of dietary and physical activity patterns.

How prevalent is it globally?

Hyperglycaemia in pregnant women aged 20 to 49 was about 16.9%, affecting 21.4 million live births, in 2013, and estimates show more than 90% of women live in low- and middle-income countries. (1) Most cases are in South-East Asia and the region with the second amount is Africa.

How prevalent is it in Africa?

Prevalence is about 14% in Africa. 14 studies conducted in six African countries found a prevalence from 0% to 13.9%. (1)

What are the medical device treatments and do they work?

Continuous glucose monitoring (CGM) has been proved to effectively support diabetes management in pregnant women with GDM by improving HbA1c compared with usual antenatal care without increasing severe hypoglycaemia. (1,2)

A CGM works through a tiny sensor inserted under the patient’s skin, usually on their belly or arm. It measures interstitial glucose level, which is the glucose found in the fluid between the cells and tests glucose every few minutes. A transmitter wirelessly sends the information to a monitor, such as a mobile phone. (4)

One study conducted using the Dexcom G6 CGM system on thirty-two participants with T1D (n = 20), T2D (n = 3), or GDM (n = 9): 19 in the second trimester and 13 were in the third trimester of pregnancy, proved to be accurate and safe for pregnant women with GDM. Compared with the reference, 92.5% of CGM values were within ±20%/20 mg/dL. The overall MARD and that of sensors worn on the abdomen, upper buttock, and posterior upper arm was 10.3%, 11.5%, 11.2%, and 8.7%, respectively. There were no device-related adverse events. Skin reactions where sensors were inserted into the skin were non-existent or minor.

Another study conducted with 50 women with insulin-treated GDM randomized to either retrospective CGM (6-day sensor) at 28, 32 and 36 weeks’ gestation (Group 1, CGM, n = 25) or usual antenatal care without CGM (Group 2, control, n = 25) also had positive outcomes. There was a lower increase in HbA1c from 28 to 37 weeks’ gestation in the CGM group [∆HbA1c: CGM + 1 mmol/mol (0.09%), control + 3mmol/mol (0.30%); P = 0.024].  (3) Mean HbA1c in the CGM group was lower at 37 weeks compared with controls [33 ± 4 mmol/mol (5.2 ± 0.4%) vs. 38 ± 7 mmol/mol (5.6 ± 0.6%), P < 0.006]. (3)

Results show that CGM can be beneficial in supporting women’s health with the treatment and management of GDM during pregnancy.

Sources: 

1. https://onlinelibrary.wiley.com/doi/full/10.1111/tmi.12521
2. https://www.liebertpub.com/doi/full/10.1089/dia.2020.0085 
3. https://onlinelibrary.wiley.com/doi/abs/10.1111/dme.13649 
4. https://www.niddk.nih.gov/health-information/diabetes/overview/managing-diabetes/continuous-glucose-monitoring