Female Health Series:

Fertility and Charting the Menstrual Cycle

There are two key elements to observe in regards to female infertility, ovulation and menstruation.

In Chinese medicine, we observe very closely any change from what we consider ‘the norm’ or a deviation from ‘health’. This can become very intricate and delicate, where some of the factors we may observe are body temperature changes, skin colour, tongue, pulse, tender areas and of course, the regularity and observations of the period.

The basal body temperature (BBT) chart is a fairly recent addition to Chinese medicine diagnostics, and has only been used the last 20-30 years in a scale of 3,000 – 5,000 years history.

What we will be looking at today is the BBT chart and how to read it in regards to Chinese medicine. But first we will look at a snapshot of a standard 28 day cycle and how hormones naturally peak.

As we can see above during bleeding in the First 1-5 days, the uterine endometrial lining sheds and there is a low activity of female hormones oestrogen and progesterone. Around day 7-12 one follicle is excreted, estrogen is produced which stimulates the uterine lining to proliferate. The glands in the cervix will also start to produce fertile mucous.

Day 12-13 The highest level of estrogen acts on the pituitary gland making it produce Leutinizing Hormone (LH).

Day 14 The egg is released when the enzymes create a break in the follicle wall.

Day 15-25 Progesterone is produced, stimulated by the empty follicle and stimulates the endometrium to secrete nutrients. The pituitary is then inhibited o produce FSH and LH.

Day 25-28 The corpus luteum (latin for yellow body is a temporary structure in the uterus made primarily from lutein, which is synthesised from egg yolks, green leafy vegetables and yellow carrots in the diet) dies and progesterone and estrogen levels drop, causing the endometrium to disintegrate and the period to flow.

The BBT chart is a way of measuring the ovulation time and peaks and troughs of hormones. The temperature is measured upon waking every morning (preferably with a mercury thermometer as the others are innacurate) and we can see if there is a peak rise in temperature midcycle (this should indicate ovulation).

Above is a typical 28-30 day cycle BBT chart. We can see around day 14 there is a drop and then a peak which starts around day 15-17, this is progesterone kicking in just after ovulation which has a direct effect on the temperature regulating part of the body.

To start charting all you need are three things, a BBT chart or iPhone ap, a thermometer, and a good night’s sleep. Charting starts on day 1 of your period, which is the first day of bleeding. If you have a very irregular cycle then just keep going until we notice a pattern.

Upon waking in the morning, put the thermometer in your mouth for 3-5 minutes, and note the temperature on your chart. Note, it is best to take the temperature at the same time every morning as later in the day will give you an erratic reading. It is also a good idea to check other signs and symptoms and record them such as breast tenderness, spotting, bloating, abdominal pain, and cervical mucous. Cervical mucous differences can be seen in the picture below. A mucous that is too thick and not ‘stringy’ around ovulation is counterproductive to fertility as sperm have a hard time swimming through it.

In the next post we will look at different types of BBT charts and how to read them and how Chinese medicine approaches abnormal charts.