Before starting treatment the couple’s infertility should be assessed as appropriate and putative contraindications for pregnancy evaluated. Women should be evaluated for hypothyroidism, adrenocortical deficiency, hyperprolactinemia and pituitary or hypothalamic tumors, and appropriate specific treatment given. For single subcutaneous injection only. In the first seven days after administration of corifollitropin alpha, no (rec)FSH should be administered. Not recommended in combination with a GnRH agonist. Use not recommended in women with polycystic ovarian syndrome (PCOS). Signs and symptoms of OHSS are stimulated by administration of human Chorionic Gonadotropin (hCG) and by pregnancy (endogenous hCG)(adherence to the recommended dose and treatment regimen; careful monitoring of ovarian response is important to minimize the risk of OHSS). Ovarian response was shown to be higher after treatment with corifollitropin alpha than after treatment with daily (rec)FSH. Multiple pregnancies and births have been reported for all gonadotropin treatments. Since infertile women undergoing ART, and particularly IVF, often have tubal abnormalities, the incidence of ectopic pregnancies might be increased (early ultrasound confirmation that a pregnancy is intrauterine is important). The incidence of congenital malformations after ART may be slightly higher than after spontaneous conceptions. Ovarian and other reproductive system neoplasms, both benign and malignant, have been reported in women who have undergone multiple treatment regimens for infertility treatment. In women with generally recognized risk factors for thromboembolic events, such as a personal or family history, severe obesity (Body Mass Index >30 kg/m^2^) or thrombophilia, treatment with gonadotropins may further increase this risk.