Navigating Gestational Diabetes and High BMI during Pregnancy

Decision making during pregnancy is complex as it is, but adding in gestational diabetes and a high BMI can take it to another level.

Navigating your choices and decision making during pregnancy and birth, especially with considerations like BMI and gestational diabetes (GD), can be complex.  In fact, the word complex is a bit of a disservice; let’s give it two words; perplexing and problematic!

I would therefore recommend to keep the following key points in mind:

Issues around diagnosing GD:


The diagnosis for GD is not clear cut. Guidelines and tests differ widely between countries and areas and the incidence of GD varies globally from 2% to 26% depending on the definition used, the approach to screening, and the population of women tested. Go to this brilliant blog by Dr Rachel Reed (updated November 2023) for more info: Gestational Diabetes: Beyond the Label.

Limited scientific studies:


There’s a scarcity of scientific studies on the risks and care associated with both GD and higher BMI pregnancies. This lack of evidence can make decision-making challenging for parents and tends to make medical practitioners more risk-averse and often any advice is based upon opinion, and also not knowing what the risk or chance is of that thing happening.

Guidelines vs. Rules:


Recommendations from care providers are often based on guidelines rather than strict rules. Many are not evidence-based, emphasizing the importance of understanding that they serve as guides rather than concrete directives.

Induction of labour and GD:


There is no evidence showing induction of labour is beneficial for women with GD, and that applies to women of any BMI, i.e. a small trial has shown no significant difference in outcomes between induced and spontaneously started labours. I would highly recommend  getting yourself a copy of ‘Inducing Labour: Making Informed Decisions’ by Dr Sara Wickham which has details of all the studies and trials, or lack of! 

pregnant with scan


Concerns about larger babies:

The concern of shoulder dystocia in larger babies (>4kg) is not as prevalent as you might think. Studies show that 94% of ‘larger’ babies do not experience shoulder dystocia, and when it does occur, healthcare professionals are trained to respond effectively and so it rarely has serious consequences. Sometimes it’s worth knowing the numbers.

Inaccuracies in measurements:


The margin of error in measuring babies in utero is 15%, which is pretty huge(!) and it can be even more challenging with those women with a higher BMI. Studies also reveal discrepancies between estimated birth weight and actual birth weight – for example a study showed only 55% of the babies scanned and predicated to be larger than gestational age were actually larger at birth –  emphasizing the need for caution in relying solely on measurements.

Understanding risks:


Identifying and understanding the actual risks is crucial, as individual tolerance for risk varies. Changing the word ‘risk’ to ‘chance’ of that thing happening can often remove some emotional baggage and asking what the ‘absolute’ risk is will definitely help you both get a more realistic picture.  Plus, seeking information and evidence in brilliant books like “Plus Size Pregnancy” by Dr Sara Wickham (2023) can empower you with the necessary data to make informed decisions.

Empower yourself using BRAIN:


Always ask questions, seek alternatives, and use the BRAIN technique (what are the Benefits, Risks, Alternatives, what does my Intuition tell me, and what if we do Nothing) to clarify your thoughts. Take your time, discuss with your partner, and ensure you’re comfortable with the chosen path.

Remember, you have the right to be informed, ask questions, and actively participate in decisions regarding your pregnancy and birth. Educate yourself, trust your instincts, and advocate for the care that feels right for you.

Finding support with an independent birth professional, such as a coach like myself or a birth doula can be really valuable. They can help you sift through all the info, look at the evidence, determine your options and help you make decisions that are right for you and your circumstances.

Debbie Willis from Better Birth & Baby 

[Debbie is a Pregnancy and Birth Coach, Hypnobirthing Practitioner and Antenatal Educator helping couples to navigate their pregnancy and birth journey for a positive birth experience]

Navigating gestational diabetes and a high BMI during pregnancy



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