The impact of letrozole administration on oocyte morphology in breast cancer patients undergoing fertility preservation.

Abstract: Patients submitted to oncological fertility preservation with letrozole and gonadotropins seem to present a higher rate of immature oocytes and lower fertilization rates in comparison to infertile patients submitted to IVF cycles with gonadotropins. The aim of this study was to evaluate the influence of letrozole on oocyte morphology in patients with breast cancer submitted to fertility preservation.

Methods: Retrospective analysis performed at a public tertiary hospital in São Paulo, Brazil.

ANDRO-IVF: a novel protocol for poor responders to IVF controlled ovarian stimulation.

Objective: This study aimed to assess a novel protocol designed to improve poor ovarian response through intra-ovarian androgenization. The endpoints were: number of oocytes and mature oocytes retrieved, fertilization, cancellation and pregnancy rates.

Methods: This prospective crossover study enrolled poor responders from previous ovarian stimulation cycles submitted to a novel protocol called ANDRO-IVF.

Association between leukaemia inhibitory factor gene polymorphism and pregnancy outcomes after assisted reproduction techniques.

Certain gene polymorphisms are associated with implantation failure and pregnancy loss. Studies of leukaemia inhibitory factor (LIF) gene polymorphisms are scarce. The LIF single nucleotide polymorphism (SNP) thymine (T)/guanine (G) (rs929271) was studied in women to determine whether an association existed with pregnancy outcomes after intracytoplasmic sperm injection (ICSI); 411 women who underwent ICSI were recruited.

Depot versus daily administration of gonadotrophin releasing hormone agonist protocols for pituitary desensitization in assisted reproduction cycles.

Background: Gonadotrophin-releasing hormone agonist (GnRHa) has been widely used in cycles of in vitro fertilization (IVF). Among the various types of GnRHa ovarian stimulation protocols, the long protocol presents the best clinical pregnancy rates per cycle initiated (GnRHa administration until the suppression of ovarian activity is evident, within approximately 14 days). There are two types of GnRHa administration that can be used to lead to hypophysis desensitization in the IVF cycle in the long protocol: one consisting of daily GnRHa low doses, and another with the administration of analogues in higher long-acting doses (depot).