cervical mucus (changes during the ovarian cycle)

Last reviewed 01/2018

The period prior to ovulation is characterised by oestrogen dominance. After ovulation, progestogen and oestrogen are both secreted by the corpus luteum.

Ovulatory mucus is clear and copious. It exudes out of the cervix and can be drawn out into a fine thread - spinnbarkheit. A good quality mucus has a pH of 6.5 or less and may be threaded to at least 6 cm.

The mucus becomes more thick and rubbery after ovulation due to the influence of progestogen.

Changes in cervical mucus can also be observed by drying mucus on a microscopy slide. As ovulation approaches drying mucus develops a characteristic 'ferning' pattern.