I am extremely lucky, and i feel it acutely. At the time of my miscarriages i didn't even think to look for this sort of thing, even though my sister had it, i thought it was nothing to do with me. Daft i know.

During PG i only gained 6kg (i was 101kg at term, i'm 181cm tall), after the birth i lost about 24kg in 4 months (unmedicated, breastfeeding). My thyroid, it seems, was normalised by pregnancy then went into overdrive after the birth (post partum hyperthyroiditis) then dropped back to very sluggish because my no-longer-pregnancy-supressed immune system attacked it. I quit BFing when DD was 7 months old and waited to see if my thyroid would recover. It didn't, but it DID improve a bit even without medication. I then gained about 3kg back, but by this time a) i had begun a low dose of thyroxine and b) i was in the middle of training for a half marathon and was running about 30-45kms a week. These things will obviously have helped contain any potential weight gain.

My sister also has Hashimoto's and is morbidly obese (she overeats, i'm not going to pretend otherwise, but though it's overeating that made her so overweight, the thyroid problem does make losing much harder and she's so big exercise is a problem for her, she's been medicated for 10 years or so), and the first thing she said when i told her what was wrong was "But you can't have it, you're not fat". I still (despite training) managed to gain those 3kg on the lower dose of thyroxine and it is only now, 3 months after beginning my higher dose, that i feel normal again and have dropped the 3kg. I still exercise a lot. I was running 70kms a week, then i had to stop after the half marathon due to an injury and switched to the pool, and was swimming about 7kms a week (over 3 60-minute sessions). This week i've begun running again and started up bodypump and to make room have dropped one of the 3 swims. So i now run 3 times (only 4k runs though while i regain my strength), swim (2k-2.5k a session) twice and do bodypump once a week. I think (i've not weighed myself but my flab seems looser) i'm slowly losing still. My BMI is about 24 just now.

I have always gained weight easily and i know now i will never be one of those "naturally thin" types, but through exercise i can see the benefits of this - i store energy well so i'm like the duracell bunny - never quit! I gain weight easily but this means gaining muscle mass is easier for me too, and extra muscle can help improve your metabolic rate. My GP said i will probably always need to exercise to control my weight to within the healthy BMI range, but that isn't a problem for me as i genuinely enjoy it and there are SO MANY things one can have a go at, until you find something you like.

I'm sorry for you Kaylene_01, that you've had problems with pregnancy. My GP has told me given my last pregnancy (where the natural pregnancy steroids inhibited my immune response and allowed my thyroid to function more normally) that he anticipates no problems for me now i'm medicated and though he'll be keeping a close eye on me when i try for #2 i shouldn't anticipate problems. So while hypothyroidism can be a problem for conception/PG, once you're treated, depending on WHY you have it, it needn't necessarily be a problem anymore.

Best of luck

Bx