To think they shouldn’t need to calculate my BMI right now?

[PiePlease]

Hi all, am currently pregnant with DC2 and in my area the maternity notes are all digital. Checked my NHS app this week and noticed that at my last (29 week) appointment my updated weight has been used to calculate my BMI - but when you check the NHS page for BMI calculations it says that their BMI calculator shouldn't be used when pregnant.

So that got me thinking, surely there’s little value in re-calculating BMI right now? As calculations are based on a persons weight and height, but doesn’t account for the weight of baby/placenta/extra blood etc. Surely tracking overall weight gain might be more useful to determine risk factors for things like GD and preeclampsia etc?

YANBU it’s all BS

It's automatic. Nobody is actually using it for anything. Chill.

It's most definitely not BS as pp said.

A raised BMI over 30 can potentially lead to complications for both the mother and baby in pregnancy and childbirth.

Yes I do think that for most people there’s value in calculating it initially, but my thoughts are that it’s not a valid measure of risk when you account for the weight of the baby/placenta/blood volume increase further on in pregnancy.

When you google ‘BMI over 30 pregnancy’ the top result from an NHS publication says: Research shows that women who have a BMI above 30 at the start of their pregnancy are more likely to develop complications during their pregnancy, labour and birth. So I think 30+ is probably referring to initial calculations, not anything calculated later on

Agree that it’s not likely used for anything, and am not overly concerned about it but it just got me thinking and I wondered if there’s any value in it

Can pregnant women not go over 30 while pregnant without factoring in babies weight? Does the risk not appply after confirmed pregnancy?

It seems as though guidance around this both from NHS and NICE relates to BMI as recorded at the booking appointment, not later on in pregnancy.

The NHS doesn’t give a set guidance on how much weight a woman should gain in pregnancy, but they say that for someone starting at a healthy weight it’s normal to expect to gain between 10kg-12.5kg over the course of a pregnancy.

When you look at BMI charts, what’s considered a healthy BMI is often a figure within a range of 10kg-15kg for an average height person, so the normal pregnancy weight gain is almost guaranteed to push a high percentage of women into the ‘overweight’ category over the course of a healthy pregnancy. Unless you started out right at the bottom of the ‘normal’ BMI range, or were classed as ‘underweight’ to start.

So if you check your BMI at the end of third trimester, and it pulls through as 30, I don’t think that means that you’re higher risk of certain conditions (which you might have been deemed, had 30 been your initial BMI as calculated at the booking appointment) as the measure is simply not designed for use at that stage of pregnancy

Yes they can and do. With consent we will reweigh some women at end of pregnancy if they haven't been reweighed since their first appt.
BMI/weight is used to calculate drug amounts as well.

I put on 30 kg for my first pregnancy, 20 for the second. I was so hungry all the time😅. I quickly lost it though so really don't think it matters..