Birth Small Talk

Talking about birth

Gestational diabetes and CTG monitoring: What does the evidence say?

Photo by Kate on Unsplash

All major obstetric organisations recommend the use of continuous CTG monitoring in labour for women with gestational diabetes. This is in line with the general approach of recommending CTG monitoring for women who have any risk factor for poor perinatal outcome. The majority of the randomised controlled trials which have compared the use of CTG monitoring with intermittent auscultation in populations of women considered to be at increased risk have not examined outcomes according to the specific risk factor, instead mixing all women with risk factors in together. The only exception to this was the small trial conducted by Madaan and Trivedi (2006) where the risk factor was previous caesarean section. This makes it challenging to provide specific and accurate counselling to women with a risk factor as they make a decision about intrapartum fetal heart rate monitoring.

Jabak and Hameed (2020) recently asked whether the use of CTG monitoring in labour for women with gestational diabetes can be justified on the basis of existing evidence. Their literature search (unsurprisingly) located no randomised controlled trials addressing this question. Two observational studies were identified, one from 2011 and the other from 1983. The more recent study found that women with pre-existing diabetes were more likely to develop CTG changes categorised as pathological according the FIGO guideline criteria than women with gestational diabetes, but provided no comparison with women without diabetes, nor measures of perinatal outcome. The older study included women who were managed with insulin without clarifying whether they had pre-existing diabetes or new onset in the current pregnancy. Jabak and Hameed also remind us that the diagnostic criteria for diabetes and the interpretive schema for CTG monitoring have significantly changed since this research was conducted in 1983 making it difficult to apply today. CTG abnormalities were found to be more common with insulin treated diabetes than women without diabetes. 

Jabak and Hameed conclude that “with the lack of current evidence, we find it difficult to recommend mothers with well-controlled gestational diabetes to give birth in obstetrics led unit with continuous fetal monitoring and deny them a chance to have home birth or birth in midwifery-led birth units.” The inclusion of gestational diabetes (in the absence of other complications) in professional guidelines for intrapartum fetal heart rate monitoring undermines claims that such guidelines are “evidence-based” as there is clearly no evidence to support this recommendation.

As the authors of this review point out, the requirement to use CTG monitoring impacts on other choices that women might wish to make about where and how they give birth. In the presence of guideline recommendations for CTG use, maternity clinicians who share accurate information about the lack of evidence supporting the use of CTG monitoring for women with gestational diabetes in order to support informed decision-making may find themselves at risk of complaint when women choose intermittent auscultation instead. Wouldn’t it be best for professional organisations that write fetal monitoring guidelines to genuinely support clinicians’ attempts to provide respectful and evidence-based care?

References 

Jabak, S., & Hameed, A. (2020, Dec 13). Continuous intrapartum fetal monitoring in gestational diabetes, where is the evidence? Journal of Maternal-Fetal & Neonatal Medicine, In press, 1-4. https://doi.org/10.1080/14767058.2020.1849117

Madaan, M., & Trivedi, S. S. (2006, Aug). Intrapartum electronic fetal monitoring vs. intermittent auscultation in postcesarean pregnancies. [Randomized Controlled Trial]. International Journal of Gynecology and Obstetrics, 94(2), 123-125. https://doi.org/10.1016/j.ijgo.2006.03.026

Categories: CTG, EFM, New research

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