Levels of progesterone in ovulation

Not an easy one, I am afraid. A woman with a regular menstrual cycle (anything between 28 and 42 days) is probably ovulating. This can be confirmed by measuring the levels of serum/blood progesterone – with a sample taken at the mid-luteal phase (seven days prior to menstruation). In women with a 28-day cycle, this is day 21 (and is the normal accepted day for the blood test).

This is meaningless in women who have longer cycles – or even more difficult if the cycle varies. As the luteal phase is constant (14 days), you have to work back from the day of the expected menses to arrive at the correct day for the test. In some cases of irregular cycles it may be necessary to have blood tests every third day from 21 days. Levels of over 30 nmol/l indicate ovulation. Progesterone levels below this indicate the need for other hormone assays. It is difficult to know from pregnancy states just what happens to this level, as production then appears from other sites like the developing ovum, placental tissues, etc. Sometimes, various ‘progesterones’ can be added in early pregnancy – as an effort to sustain the pregnancy, but their use is somewhat vague.

Hope you have got something of value out of all this. I wish you well with whatever problems you may have.

All the best
Dr Howard Lee