BACKGROUNDLetrozole is the third-generation aromatase inhibitor (AI) most widely used in assisted reproduction. AIs induce ovulation by inhibiting estrogen production; the consequent hypoestrogenic state increases GnRH release and pituitary follicle-stimulating hormone (FSH) synthesis.METHODSA systematic search of the literature was performed for both prospective and retrospective studies. Meta-analyses of randomized clinical trials (RCTs) were performed for three comparisons: letrozole versus clomiphene citrate (CC), letrozole + FSH versus FSH in intrauterine insemination (IUI) and letrozole + FSH versus FSH in IVF. In the absence of RCTs, non-randomized studies were pooled.RESULTSNine studies were included in the meta-analysis. Four RCTs compared the overall effect of letrozole with CC in patients with polycystic ovary syndrome. The pooled result was not significant for ovulatory cycles (OR = 1.17; 95% CI 0.66–2.09), or for pregnancy rate per cycle (OR = 1.47; 95% CI 0.73–2.96) or for pregnancy rate per patient (OR = 1.37; 95% CI 0.70–2.71). In three retrospective studies which compared L + FSH with FSH in ovarian stimulation for IUI, the pooled OR was 1.15 (95% CI 0.78−1.71). A final meta-analysis included one RCT and one cohort study that compared letrozole + gonadotrophin versus gonadotrophin alone: the pooled pregnancy rate per patient was not significantly different (OR = 1.40; 95% CI 0.67–2.91).CONCLUSIONSLetrozole is as effective as other methods of ovulation induction. Further randomized-controlled studies are warranted to define more clearly the efficacy and safety of letrozole in human reproduction.

BackgroundThe aim of this report was to describe a case of pregnancy after drug-free in vitro activation (IVA) of follicles and fresh tissue autotransplantation in primary ovarian insufficiency (POI) patient and to review the pertinent literature.MethodsWe present a case in wich a 32 - years old patient with POI became pregnant after IVA without tissue culture and with ovarian tissue transplantation. We also reviewed the literature using Pubmed database.Case presentationPretreatment with estradiol/progesterone stopped the day before surgery. The removal of the ovarian cortex and autotransplantation were performed by laparoscopy in the same surgical act. Ovarian fragments were transplanted in contralateral ovary and peritoneal pocket near to the ovary. Immediately after surgery GnRH agonist together HMG injections started, leading the growth of 3 preovulatory follicles and the retrieval of two mature eggs. After IVF two embryos were transferred and singleton pregnancy was established and currently she is 25 weeks pregnant.ResultsA total of 51 patients with POI in whom an in vitro activation of ovarian tissue was performed, were collected from the revieew of the literature. In 29.4% of them, follicular development was obtained and in 4 of them a pregnancy. In all of them, a combined technique (fragmentation and activation) was performed in two laparoscopies. No case has been reported successfully after drug-free in vitro activation.ConclusionsThis is the first report about a case with pregnancy after drug-free in vitro activation of follicles and fresh tissue autotransplantation in POI patient.

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Research question: What are the effects of the early phase of COVID-19 pandemic on natural and ART-mediated birth rates?Design: Upon permission by Health Authorities of Lombardy Region, Northern Italy, an area that was particularly affected by the epidemic in the early phase, regional registries were consulted.Deliveries occurred in the area between January 1 st , 2019 and December 31 st , 2020 from women beneficiaries of National Health System (NHS) and resident in Lombardy were identified.Comparisons mainly focussed on the month of December 2020, when women who conceived after March 8 th (when stringent authorities-imposed lockdown initiated) were expected to deliver.