Yes I am pregnant and have hypothyroidism. And yes this can cause miscarriages IF you do not see a doctor and are put on medication. After I had my daughter 2 years ago I developed this.. I have to be on medication for the rest of my life to control my levels. When I got pregnant again (I am almost 14 weeks) I have to see a endocrinologist and have my blood drawn every 6 weeks to see to make sure my thyroid isn't under-active anymore. By the way hypothyroidism means you have an under-active thyroid. I am fine and my baby is perfectly healthy but this is because I take my medication every single day and see my doctor every month. You should get checked for this and your doctor should put you on medication right away. Even if you aren't pregnant it is very important to take medication because it is very serious. Good luck to you.
are you sure you have hypothyroidism? have you had the blood tests to confirm? if so, yes, thyroid problems can affect pregnancy. if your doctor is certain you have this condition, he should be sending you to a high risk doctor if he doesn't know how to manage this problem while you are pregnant. i have heard that hypothyroidism can cause issues with brain development for the baby that usually affects them after birth but i have never heard of it causing miscarriage. you may want to find a doctor that specializes in this.