What Are the Causes of No LH Surge?

Woman track the timing of their luteinizing hormone (LH) surge to predict ovulation, to encourage or prevent pregnancy. Some women discover irregular ovulation or an absence of ovulation completely. In most cases this is caused by a hormone imbalance and the absence of the LH surge.

Function

• Luteinizing hormone is produced in small quantities throughout a woman's menstrual cycle. Mid-month, the luteinizing hormone undergoes a short but dramatic increase, or surge, which triggers the follicle to release a matured egg.

Significance

• The luteinizing hormone triggers ovulation. Without a mid-cycle LH surge, the ovary will not release an egg, which causes irregular menstrual cycles and prevents pregnancy.

The Facts

• Any disruption in a woman's hormones can trigger either high or low levels of luteinizing hormone, causing a disruption in the typical surge experienced mid-cycle.

Polycystic Ovary Syndrome

• Polycystic Ovary Syndrome (PCOS), a common condition in young women, has a diagnoses rate of one in ten women. PCOS causes a hormone imbalance in the brain and ovaries, which results in a high level of luteinizing hormone throughout the cycle, making the mid-cycle surge unlikely.

Polycystic Ovary Syndrome Signs

• The most common sign of PCOS is irregular menstrual periods, which either come too frequently, or are skipped all together. Other signs include extra hair on your face or other body parts, acne, trouble maintaining weight, and patches of dark skin.