Nifedipine Treatment on Uterine Contractility in IVF

The main factors associated with pregnancy rate in In Vitro Fertilization (IVF) treatment are embryo quality and the uterine ability to accept the embryo for implantation. This ability is influenced by uterine contractions (UC), which change in pattern and direction during the menstrual cycle. An abnormal uterine contraction pattern can displace the embryo from the proper position in the uterine cavity towards the cervix or the fallopian tubes and as a result may decrease pregnancy rates and increase the risk of ectopic pregnancy. Indeed, previous studies demonstrated a negative correlation between uterine contraction rate and implantation/pregnancy rates. Suppression of uterine contractions during embryo transfer can be achieved by a large array of drugs, such as cyclo-oxygenase inhibitors, β2-adrenoreceptor agonists, calcium-channel blockers, phosphodiesterase inhibitors and oxytocin antagonists. The objective of this study is to evaluate the efficacy of Nifedipine administration in reducing uterine contractility during IVF-frozen embryo transfer (FET) treatment.