Thyroid disorders are of 2 types:

Hypothyroidism:

It is a more common condition in which thyroid gland doesn’t produce sufficient thyroid hormone. The condition can be asymptomatic while in severe forms can affect full body functioning, resulting in slow metabolism, impair ovulation. It is diagnosed by raised TSH levels.

Hyperthyroidism:

In this condition thyroid glands produces excess thyroid hormones & characterized by decreased TSH levels.
As Hypothyroidism is much more common we will discuss its effects on fertility & pregnancy.

• Ovulation:Hypothyroidism impairs ovulation if treated adequately & on time the effect of hypothyroidism on fertility can be reversed & ovulation restored.
  • Miscarriage: Hypothyroidism can increase the risk of early pregnancy loss.
  • Pregnancy Complications: Foetus depends on mother’s thyroid hormone reserve for first 10-12 weeks of gestation & problems with thyroid production can pose risk to foetus. Untreated Hypothyroidism can give rise to conditions like Pre Eelampsia, Placental Abruption, Premature delivery, low birth weight & still birth.
  Recent studies have suggested that TSH should be no higher than 2.5 mIU/L when trying to conceive & 3.0 mIU/L during pregnancy.