Would thyroid issues such as, hypothyrism, increase the chance of having abnormalties or birth defects to my pregency?

Probably not: While there are no increased risks for birth defects for thyroid disorders, it would be most important to have your thyroid disorder controlled. Uncontrolled over or under active thyroid metabolic problems can have an impact on the metabolism of your baby -- perhaps leading to improper development of the thyroid gland in utero. This may result in metabolic, cardiac and hormonal problems.

Can endanger pregnan: Hypothyroidism can certainly endanger your pregnancy and lead to miscarriage or fetal compromise. The fetus depends upon your thyroid for the first 8-12 weeks. Make sure your thyroid level is normalized with brand name T4 replacement, and do it before you become pregnant. Check level during pregnancy as replacement needs can change significantly while pregnant.