Progesterone and estradiol in saliva after in vitro fertilization and embryo transfer.

The importance of the luteal function to ensure adequate implantation prompted us to assay salivary estradiol (SE2) and salivary progesterone (SP) concentration serially after embryo transfer by simple and rapid radioimmunoassays to allow a noninvasive easily repeatable approach. SE2, which has fallen 1 day after human chorionic gonadotropin injection, increased after reimplantation (day 3), plateaued during approximately 1 week, and returned to basal levels before menstruation in absence of conception or in chemical pregnancy, whereas it increased steadily in successful pregnancy. SP increased in all the cases, formed a plateau, and returned progressively to basal levels before menstruation, whereas in ongoing pregnancy there was a transitory decline in the midluteal phase followed by a rapid and continuous increase, with a significantly higher ratio day 13/day 10 in successful pregnancy.