There are three methods that we will look at in detecting ovulation. Ovulation is the process of an ovarian follicle discharging an egg for the purpose of fertilisation. In this article we will look at the first of those three methods and discuss the process and its effectiveness in comparison to the others.

Detecting Ovulation with Basal Body Temperature (BBT)

A means of detecting ovulation is a routine recording of the basal body temperature.  This is the temperature when you first wake up after at least 3 hours of uninterrupted sleep. A basal thermometer is best to use for the recording as it has been designed to indicate the slightest of change in body temperature.

The findings should be noted in a chart to keep record. What you should notice is a rise in BBT that is above 0.2 degrees celsius and maintains that way for longer than 3 days in a row, as this will show you when you ovulate.

A woman is in the period of being fertile just as there is a rise in BBT and the few days preceding this. Over  months of recording one’s BBT there will be noticeable patterns of the time in the month when one is most fertile. This information is helpful for couples wanting to plan a pregnancy.

BBT – the rise and fall

Rises and falls actually result from the action of the 2 types of hormones (estrogen and progestogen) elaborated by the ovary.

Each month the reproductive system in a woman of childbearing age undergoes highly complex changes during her menstrual cycle. Estrogen and progesterone are two critical hormones that ensure that an egg is released by the ovary at the middle of each cycle. Ovulation depends on production of these and other hormones at the right time and in the correct amounts.

The part of a cycle leading up to ovulation is called the follicular phase because it’s characterized by growth of the ovarian follicle. This phase lasts about 14 days and ends just before ovulation.

The pituitary hormone FSH stimulates follicle cells to make estrogen in steadily increasing amounts during this phase, and also to make fluid that forms a central, fluid-filled cavity in the follicle. In the follicle, estrogen stimulates follicle cells to divide, eventually causing the follicle to increase greatly in size as ovulation approaches. As estrogen levels increase in a woman’s blood, the hormone exerts a positive effect on the pituitary, which begins to respond by releasing small amounts of LH. Although LH levels remain relatively low during this phase, it nevertheless stimulates follicle cells to make small amounts of progesterone, which becomes important at the time of ovulation.

Attending appointments with a professional Obstetrician and Gynaecologist will help equip you with a plan that is derived on clinical evidence as to best prescription for detecting ovulation within a pregnancy plan.

Dr Gary Swift is an Obstetrician and Gynaecologist who has a clinic in Benowa on the Gold Coast. The contact us page on this website can help you with making contact with the clinic.