[Uterine contractility and reproduction: new perspectives].

The contractile activity of the nonpregnant uterus plays an important role in the human reproduction process. Noticeable variation in uterine contractility occurs during the menstrual cycle to meeting some physiologic requirements of the female reproductive system. During the follicular phase, stimulation of uterine contractions by estrogens fosters sperm transport toward the fertilization site. After ovulation, contractility decreases in response to progesterone, a phenomenon that is probably involved in the embryo implantation mechanism. The comprehension of uterine contractility regulation and physiologic roles has been considerably extended during recent years by the development of direct and noninvasive assessment tools, in particular, ultrasound. Today, not only the artificial stimulation of uterine contractions, aiming at promoting sperm transport during the pre-ovulatory phase, but also their attenuation to provide optimum conditions for embryo implantation during the luteal phase, represent innovating, promising issues in the optimization of assisted reproduction treatments.