Thyroid UK

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Breastfeeding - Thyroid blood reference ranges

In pregnancy the reference ranges are lower for tsh. Anyone know if there are some reference ranges for lactating women? Thanks

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TiredBFmum,

There isn't a seperate reference range for breastfeeding women.

It's never occurred to me before, but I think there ought to be!

HB,

Why? The only reason there is a seperate range for pregnancy is because pregnancy hormones can affect thyroid levels.

Because if a woman struggles to produce thyroid hormones in the first place, and she is providing sustenance to a hungry infant her thyroid hormones may struggle to keep up.

I would have compared feeding an infant when the mother has thyroid disease to being akin to exercising a lot with thyroid disease or dieting a lot with thyroid disease, and I wouldn't think either of those two things were a good idea for many of us.

Maybe I just have a woolly idea about the strain that breastfeeding has on the body. I've never had any offspring so breastfeeding is a bit of a black art as far as I'm concerned.

Hormones are very different for breastfeeding women - it alters hormones in a big way but less than pregnancy itself and the menopause. For example, that's why some (not all) women don't get periods back until they stop breastfeeding.

Also, a lot of vitamins and minerals go from the mother into the milk. The iodine required by a breastfeeding woman is extremely high as breastmilk is so high in iodine. It just makes me wonder how it affects thyroid function and therefore how it will affect my thyroid function test results.

TiredBFmum,

Shouldn't you have a follow up thyroid test a few weeks after delivery to check?

I'd never thought of this! I'm currently breastfeeding and my thyroid issues got highlighted postpartum. I suffered for years before my pregnancy and had terrible symptoms but at the moment they're not as bad and I do put that down to breastfeeding. I'm not having periods so I don't think my treatment at the moment is a true reading of how my thyroid effects me.

Have you spoken to a gp about varying results due to breastfeeding etc?

At the beginning of pregnancy i increased the dose because tsh was over 4.

I had better results after my son was born. My tsh dropped at 0.7 and ft3, ft4 increased so i thought to reduce my dose. Big mistake.

Have your results changed as your son has got older? I have wondered if mine need rechecking as I start to wean my son because surely all your hormones and vitamins change when you stop breastfeeding?

There was no change after i weighed the baby. The biggest change in results was at beginning of pregnancy and 3 months after my son was born. If at least 3 months have passed you can verify your hormones