Menstrual irregularities and lactation failure may precede thyroid dysfunction or goitre.

Menstrual and reproductive history of 178 women referred to the thyroid clinic was compared with 49 healthy controls. Cases were classified as euthyroid, hypothyroid or hyperthyroid after clinical examination and after serum T3, T4, TSH measurements. Reproductive history was related chronologically to symptoms and signs of thyroid dysfunction. Only 31.8% of hypothyroid and 35.3% of hyperthyroid women had normal menstrual pattern in contrast with 56.3% of Euthyroid and 87.8% of healthy controls (p < 0.001). Reproductive failure (infertility, pregnancy wastage, failure of lactation) occurred in 37.5% of hypothyroid and 36.5% of hyperthyroid cases against 16.3% of euthyroid and 16.7% of healthy controls (p < 0.05). Interestingly, in 45% of cases with menstrual abnormality, the anomaly was antecedent to other clinical features by a variable period of two months to ten years. Reproductive failure and lactation failure also preceded thyroid dysfunction or goitre. Reproductive dysfunction may therefore be considered as one of the presenting symptoms of thyroid disorders in women, keeping in mind both menstrual irregularities and lactation failure may also arise from other common or idiopathic origins. Especially in women with menstrual irregularities in the perimenopausal age if thyroid dysfunction is detected, pharmacotherapy may be a superior alternative to surgical interventions like hysterectomy.