Hormones
An overactive thyroid may cause light or absent periods, weight loss and palpitations, and untreated disease increases pregnancy risks. Treatment choice matters before conception because some medicines are preferred in early pregnancy — this needs specialist advice.
Also known as: overactive thyroid, Graves disease
Related Canada guides
Sources
- Society of Obstetricians and Gynaecologists of Canada (SOGC) patient information
Last reviewed: September 9, 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.