Assisted reproductive technology in Latin America: the Latin American Registry, 2017.

RESEARCH QUESTION: What was the utilization, effectiveness and safety of assisted reproductive technologies (ART) carried out in Latin America during 2017. DESIGN: Retrospective collection of multinational data on ART carried out in 188 institutions from 15 Latin American countries. RESULTS: In this study, 93,600 initiated cycles, 16,976 deliveries and 20,404 births reported. Utilization of ART was 221 cycles per million inhabitants (15 to 535). Women aged 40 years and above represented 30.5% of fresh IVF and intracytoplasmic sperm injection (ICSI); however, after removing freeze-all cycles, delivery rate per oocyte retrieval was 19.9% for ICSI and 20.2% for IVF. Overall, single embryo transfer (SET) represented 26.9% of fresh transfers, with 18.2% delivery rate per transfer, increasing to 32.3% in elective SET. Delivery rate in double embryo transfers (DET) was 28.3% increasing to 37.3% with elective DET. This 5% increment in births in elective DET over elective SET resulted in a tenfold increase in twin births, gestational periods almost 3 weeks' shorter and a threefold increase in perinatal mortality. Delivery rate in frozen-thawed SET reached 25.5% increasing to 30.8% with DET, most being blastocyst transfers. Of all births, 66.9% were singletons, 31.4% twins and 1.6% triplets and higher. Overall, preterm deliveries reached 9.5% in singletons, 64.3% in twins and 97.9% in triplets; perinatal mortality was 9.4‰ in singletons, 25.3‰ in twins and 63.3‰ in high-order multiples. CONCLUSIONS: The number of initiated cycles has slowly increased. Frozen embryo transfers, blastocyst transfers and SET are also increasing. Our data show that, especially in young women and oocyte recipients, when there is more than one blastocyst for transfer, elective SET should be the rule.

Vitamin D Receptor TaqI Polymorphism Is Associated With Reduced Follicle Number in Women Utilizing Assisted Reproductive Technologies.

PURPOSE: Calcitriol, or 1,25-hydroxycholecalciferol, is the active form of vitamin D. It binds and activates vitamin D receptor (VDR). Infertility and defective folliculogenesis have been observed in female vdr-knockout mice; however, whether VDR polymorphisms affect human ovarian responses to controlled ovarian stimulation (COS) remains unclear. We hypothesized that VDR polymorphisms are associated with infertility and COS responses. Thus, we evaluated the association between the TaqI, BsmI, and FokI VDR polymorphisms and ovarian responses in women undergoing COS. METHODS: In this study, we recruited a control group (n = 121) comprising volunteers with a history of natural conception and a second group of women undergoing COS (n = 70). TaqI, BsmI, and FokI genotyping was performed via restriction fragment length polymorphism analysis or TaqMan qPCR and Sanger sequencing. Intrafollicular 25(OH)D contents were measured in follicular fluid collected from COS patients during oocyte retrieval. Ovarian response parameters were obtained from patient medical records. RESULTS: There were no significant differences in the genotype frequencies of VDR polymorphisms (TaqI, BsmI and FokI) between the control and COS groups. However, the allele frequency of TaqI (C allele) was significantly lower in the COS group than in the control group (p = 0.02). Follicle number but not oocyte number was lower in patients with TaqI polymorphic (TC/CC) genotypes (p = 0.03). Importantly, the ratio between the number of follicles retrieved and intrafollicular estradiol concentrations was higher in patients with the TC/CC TaqI genotypes (p < 0.02). CONCLUSION: We identified an association between the VDR TaqI polymorphism and reduced follicle number in women undergoing COS, suggesting that VDR signaling affects the ovarian response to stimulation via unknown mechanisms.