Barriers to completing oral glucose tolerance testing in women at risk of gestational diabetes

Abstract

Aim Complications of gestational diabetes (GDM) can be mitigated if the diagnosis is recognized. However, some atrisk women do not complete antenatal diagnostic oral glucose tolerance testing (OGTT). We aimed to understand reasons contributing to non-completion, particularly to identify modifiable factors. Methods Some 1906 women attending a tertiary UK obstetrics centre (2018-2019) were invited for OGTT based on risk-factor assessment. Demographic information, test results and reasons for non-completion were collected from the medical record. Logistic regression was used to analyse factors associated with non-completion. Results Some 242 women (12.3%) did not complete at least one OGTT, of whom 32.2% (n = 78) never completed testing. In adjusted analysis, any non-completion was associated with younger maternal age [≤ 30 years; odds ratio (OR) 2.3, 95% confidence interval (CI) 1.6-3.4; P < 0.001], Black African ethnicity (OR 2.7, 95% CI 1.2-5.5; P = 0.011), lower socioeconomic status (OR 0.9, 95% CI 0.8-1.0; P = 0.021) and higher parity (≥ 2; OR 1.8, 95% CI 1.1-2.8; P = 0.013). Non-completion was more likely if testing indications included BMI ≥ 30 kg/m 2 (OR 1.7, 95% CI 1.1-2.4; P = 0.009) or family history of diabetes (OR 2.2, 95% CI 1.5-3.3; P < 0.001) and less likely if the indication was an ultrasound finding (OR 0.4, 95% CI 0.2-0.9; P = 0.035). We identified a common overlapping cluster of reasons for non-completion, including inability to tolerate test protocol (21%), social/mental health issues (22%), and difficulty keeping track of multiple antenatal appointments (15%). Conclusions There is a need to investigate methods of testing that are easier for high-risk groups to schedule and tolerate, with fuller explanation of test indications and additional support for vulnerable groups.

Approaches to screening for hyperglycaemia in pregnant women during and after the COVID‐19 pandemic

“…This was pertinent during the pandemic peak, when having all women attend during a small, timeframe was logistically difficult, and challenging for women without private transport. More data are required to better understand whether the requirement for an overnight fast and early‐morning attendance influences uptake of the OGTT, especially among socially disadvantaged women in real‐world clinical settings 6 …”

“…10 Although some women may refuse OGTT testing, it is clear that screening for GDM is not consistently implemented in accordance with guideline recommendations. 6,10 A recent case-control study identified a 44% greater risk of stillbirth in women with risk factors when an OGTT was not performed. 9 Likewise, women with raised fasting plasma glucose (FPG) levels who were not diagnosed with GDM experienced a fourfold greater risk of stillbirth.…”

“…6 This was pertinent during the pandemic peak, when having all women attend during a small, timeframe was logistically difficult, and challenging for women without private transport. More data are required to better understand whether the requirement for an overnight fast and early-morning attendance influences uptake of the OGTT, especially among socially disadvantaged women in real-world clinical settings 6 Unfortunately, although included in the UK, Canadian, Australian and New Zealand recommendations 5,[11][12][13] to detect overt and/or pre-gestational diabetes, we did not have data for HbA 1c in early pregnancy. Hughes et al 19 previously demonstrated that an early-pregnancy HbA 1c ≥ 41 mmol/ mol (5.9%) was predictive for diabetes and for identifying mothers and offspring at risk of complications.…”

“…A nationwide UK audit confirmed that OGTT testing was least likely to be performed in obese women and those from higher‐risk ethnic groups 10 . Although some women may refuse OGTT testing, it is clear that screening for GDM is not consistently implemented in accordance with guideline recommendations 6,10 …”

“…The alternative strategy recommends glucose testing during other hospital or community appointments to minimize additional clinical contacts. 5 The OGTT has well recognized limitations in terms of test reproducibility, tolerability and seasonal influences, 6,7 but remains the most commonly recommended diagnostic strategy for GDM. 2,3 Excess fetal growth acceleration is detectable from 20 weeks' gestation, predating diagnosis of GDM.…”