How can BMI impact fertility (natural or assisted)?
Let’s start with BMI on the higher end of the chart (keep reading for low BMI and fertility, however, because this is also significant).
Again, your safety and effective treatment are of paramount importance to us. This isn’t about a judgement of weight or lifestyle, it’s about your wellbeing, and ensuring we’re not putting you or a pregnancy at unnecessary risk.
With a higher BMI (above 25), your risk can increase for:
At conception (natural or assisted)
- poorer rates of ovulation, and response to fertility treatment drugs like letrozole and clomid
- increased need for dosing with the drug gonadotropin (which carries associated risk factors, including multiple pregnancy and OHSS)
- difficulty monitoring your follicle development, and egg retrieval
- complications during/following sedation, depending on your treatment plan
During pregnancy (and after)
- maternal health problems, such as gestational diabetes, high blood pressure and preeclampsia
- birth intervention
- postpartum complications, such as haemorrhage and venous thromboembolism
There are many factors that come into play. But top priority for us is your safety, and a treatment plan and journey that sets you up for successful, safe conception.
A note on dosages
When working out medication dosages for an IVF program, it’s often more difficult to tailor dosing to the individual, for people who are overweight, and response can be far more unpredictable. We also know that people who are overweight will require more medication to get the same yield of eggs in their IVF program.
As practitioners, our duty is to help. Patients want clarity, support and actionable next steps – which I very much aim for, in every consultation.
So for a bottom line on the ideal BMI for fertility, a high measurement (above 25) is associated with:
- a decrease in the effectiveness of fertility treatment, but also
- an increase in risk, both for your fertility procedure, and your pregnancy going forward
When we’re using medical intervention to help you have a baby, we want to achieve the best outcome, but also the safest. It’s not about saying ‘come back and see me when you’ve lost weight’ – which sadly I do hear, time and again.
It’s about saying, ‘we will work through this’.