I’ve said it for quite some time; I know high BMI in pregnancy means a greater risk of developing complications, but what if those complications don’t develop? I’ve never understood why our pregnancies can’t then be treated as ‘normal’? Is there such a thing as a low risk obese pregnancy?
At last a large study, from Oxford University no less, has asked this question:
Previous pregnancies are a better predictor of complications than BMI!
The researchers discovered that high BMI pregnancies of a second or subsequent baby, without previous caesareans, and no developed complications like high blood pressure, diabetes etc. are actually at lower risk of interventions or complications than ‘normal weight’ first time pregnancies!
The figure for intervention or complication was 21% for ‘very obese’ but healthy women having a second or subsequent baby. For ‘normal’ weight women having their first baby it was 53% – about 2 and a half times more!! What’s reassuring too, is that this was a large study, looking at 17,230 pregnancies.

Isn’t it time for more equality of access?
This begs the question: How is it fair that first-timers with supposedly low-risk pregnancies can plan to birth where they like, while those with a BMI over 35 face restrictions, even if they’ve had previously uncomplicated births?
This finding does highlight a possible anomaly in the guidance given to women on where to give birth
Dr Jennifer Hollowell, lead author of the study
As expected, the researchers found that the risks of complications during childbirth increase with increasing BMI. But the increase was modest; only 6–12% compared with those with a ‘normal’ BMI.
My experience of ‘low risk obese’ pregnancy
My first birth was (dare I say it) ‘easy’! I’d chosen to birth in hospital mainly because of a lack of confidence that my fat body would be up to the job. After all, I’d heard plenty of negativity that my labour and birth were doomed to interventions and complications. But it wasn’t the case! My labour progressed smoothly and was nowhere near as bad as films had led me to believe! I popped her out in two pushes, and despite some fairly extensive tearing which required repair, it was all good. I was denied access to the pool in the obstetric unit though, despite having been told throughout the pregnancy it would be an option.
When I was planning the birth of my second baby I met with a consultant obstetrician at 36 weeks. Access to the alongside Midwife Led Unit was out of the question at that time due to a blanket ban based on BMI. These days, most MLU should be deciding access based on individual circumstances (ask to speak to the Supervisor of Midwives), but some still ban on BMI alone.
I was determined that this time I’d have access to a pool for pain relief. Even if I’d been told I’d be permitted to use the hospital’s pool, I’m not sure I’d have trusted them, given my previous experience. So I was settling for nothing less than a home birth. The consultant was unimpressed, and tried to convince me to birth in hospital; even when I pointed out that it was the hospital’s policy forbidding high BMI women from using the birth pool that was forcing me into a home birth. Sometimes threatening home birth can open the doors to MLU, but my consultant was immovable.
Standing my ground
The consultation was a waste of time for us both. She misquoted NICE and RCOG guidance (and I corrected her). She couldn’t explain why I was ‘high risk’ when no complications had arisen. My previous birth had gone without a hint of the complications you can’t predict beforehand (shoulder dystocia, post partum haemorrhage), but she would not consider my pregnancy low enough risk to permit me to use the birth pool in the hospital. So we agreed to disagree and she signed me off to the care of my lovely, supportive midwifery team.
I then met the Supervisor of Midwives, who was far more amenable. The SoM said that she thought current policies are non-sensical and discriminatory, and that as far as she was concerned, she was more interested in my previous birth history as an indicator of how this birth would go. I’m so pleased this study validates her lived experience! She couldn’t grant me access to the MLU, not that I’d have taken the option, and I still had to sign a document saying that I was undertaking home birth against medical advice, but I was signed over to the home birth team.
However, without the discriminatory policies, I would never have had the inclination or determination to birth at home. Which was wonderful, and I’d do it again in a heartbeat. Every cloud, eh?
This is so, so refreashing to read. I myself was an “at risk” mother, partly due to my high BMI and was constantly told I’d have a big baby and diabetes and blah blah blah. None of that came to pass. I did develop PIH at the very end, so I asked for an induction. A section for a 6lb 6oz baby seems a little over kill, but I was just desparate to get out of the hospital.
When I pointed out to the midwife after the birth how healthy I’d been throughout the pregnancy, all she could say is that it quite often happens that women with high BMI, might “get away with it” once, but any more children and I’d be sure to develop all the rubbish I didn’t the first time.
So this is really interesting to read. Thank you!