High BMI raising during pregnancy

[AJMC1995]

Hi all,

I’m a FTM due in October. Just had my 28 week midwife appointment (though delayed at 29 weeks), and been weighed for the first time since my booking appointment at 8 weeks.

At booking my BMI was just over 34, so they were happy for me to be midwife led throughout pregnancy. Now I’ve only put on 9lbs through pregnancy so far, but midwife today has said my weight gain has now pushed me over BMI of 35.

This means I will be contacted by a doctor/consultant for a check up and potentially growth scans from 32 weeks. Has anyone else had this experience and it not affected much for them? My local trust has a birthing centre with pools and I was really starting to like the idea of a water birth, but now I’m worried I’ll be told no and I have to go straight to the labour ward.

Surely they knew from my start weight and BMI that I would eventually go over that cusp?

Any advice or feedback would be amazing!

This seems silly to me as you can't calculate BMI in the usual way while pregnant for obvious reasons?!?! I had a BMI of 32 at booking but I haven't been weighed since my 12 week scan, it must be different between trusts or something. It doesn't make sense to me what your midwife is telling you tho!

they're not supposed to recalculate BMI after booking (the computer software they're inputting to will calculate it anyway...just most sensible people working in obstetrics know to look at the weight not BMI). Tracking weight is fine & there are roughly normal values for increasing weight at different gestations. Weight gain outside what's roughly expected (or indeed weight loss) might trigger extra monitoring/tests/advice. Hopefully the consultant will be able to make sense of whether your current weight is what would be expected based on your starting point or whether there's anything that needs an eye keeping.