The cervix must remain closed during pregnancy to maintain the pregnancy yet open during parturition. It must perform at the right time and in the right sequence. The process that coordinates these activities is labor and it is an equal mixture of uterine contractions and cervical effacement/dilatation. Neither of these factors can be ignored if one is to understand parturition. Dilatation of the cervix depends upon the biochemical and physical processes that produce effacement. A better understanding of this active, ongoing process will enable one to manipulate them with new drugs that could produce effacement without uterine contractions. Conversely, the capacity to "stiffen" the cervix to ward off premature birth is another potential therapeutic approach that may be utilized. Research into the genesis and physical expression of the incompetent cervix is needed, as are studies of the cervix after forceable dilatation following a D and C. All of these possibilities and future advances are dependent upon our ability to quantitate the physical state of cervical tissue, both in situ and in vitro.