Ovulation Testing-Missouri Center for Reproductive Medicine & Fertility

Picture of a surgically exposed ovary with a large follicle on its surface

Above: picture of a surgically exposed ovarian follicle close to ovulation.

Ovulation is the monthly production and release of a mature oocyte (egg) from the ovary. Any disruption in this process may result in infertility. Problems with ovulation are usually seen in women who do not have regular menstrual cycles, although this can occur even in women with normal cycles.

Some of the ways to test for ovulation are listed below:

Basal Body Temperature (BBT) – a woman charts her temperature every morning before rising; approximately 2 days after ovulation, there is a sustained temperature increase of about 1 degree. If pregnancy does not occur, the temperature goes back to baseline. The photo at right is of a BBT chart showing a notable decrease in BBT at ovulation followed by the increase indicating that ovulation has occurred.

Urine LH testing – a woman tests her urine in the middle of her cycle for a hormone surge using a one-step over-the-counter ovulation predictor kit; ovulation usually occurs about 24-40 hours after the color change is seen.

Transvaginal Ultrasound – this is performed in the middle of the cycle prior to ovulation to confirm the presence of a dominant follicle (ovarian cyst with an egg inside); the thickness and pattern of the uterine lining can also be measured at this time.

Progesterone level – this is a hormone that goes up significantly only after ovulation occurs; it is a simple blood test that is performed about 1 week after ovulation.