What are the European trends and developments in ART and IUI in 2014 as compared to previous years? The 18th ESHRE report on ART shows a continuing expansion of both treatment numbers in Europe and more variability in treatment modalities resulting in a rising contribution to the birth rates in most participating countries. Since 1997, ART data generated by national registries have been collected, analysed by the European IVF-monitoring (EIM) Consortium and reported in 17 manuscripts published in Human Reproduction. Continuous collection of European data by the EIM for ESHRE. The data for treatments performed in 2014 between 1 January and 31 December in 39 European countries were provided by national registries or on a voluntary basis by clinics or professional societies. From 39 countries and 1279 institutions offering ART services, a total of 776 556 treatment cycles, involving 146 148 with IVF, 362 285 with ICSI, 192 027 with frozen embryo replacement (FER), 15 894 with PGT, 56 516 with egg donation (ED), 292 with IVM and 3404 with frozen oocyte replacement (FOR) were reported. European data on IUI using husband/partner’s semen (IUI-H) and donor semen (IUI-D) were reported from 1364 institutions offering IUI in 26 countries and 21 countries, respectively. A total of 120 789 treatments with IUI-H and 49 163 treatments with IUI-D were included. In 14 countries (17 in 2013), where all institutions contributed to their respective national registers, a total of 291 235 treatment cycles were performed in a population of ~208 million inhabitants, corresponding to 1925 cycles per million inhabitants (range: 423–2978 per million inhabitants). After treatment with IVF the clinical pregnancy rates (PR) per aspiration and per transfer were marginally higher in 2014 than in 2013, at 29.9 and 35.8% versus 29.6 and 34.5%, respectively. After treatment with ICSI the PR per aspiration and per transfer were also higher than those achieved in 2013 (28.4 and 35.0% versus 27.8 and 32.9%, respectively). After FER with own embryos the PR continued to rise, from 27.0% in 2013 to 27.6% in 2014. After ED a similar trend was observed with PR reaching 50.3% per fresh transfer (49.8% in 2013) and 48.7% for FOR (46.4% in 2013). The delivery rates (DR) after IUI remained stable at 8.5% after IUI-H (8.6% in 2013) and at 11.6% after IUI-D (11.1% in 2013). In IVF and ICSI together, 1, 2, 3 and ≥4 embryos were transferred in 34.9, 54.5, 9.9 and in 0.7% of all treatments, respectively (corresponding to 31.4%, 56.3, 11.5% and 1% in 2013). This evolution in embryo transfer strategy in both IVF and ICSI resulted in a singleton, twin and triplet DR of 82.5, 17.0 and 0.5%, respectively (compared to 82.0, 17.5 and 0.5%, respectively, in 2013). Treatments with FER in 2014 resulted in a twin and triplet DR of 12.4 and 0.3%, respectively (versus 12.5 and 0.3% in 2013). Twin and triplet DR after IUI were 9.5 and 0.3%, respectively, after IUI-H (in 2013:9.5 and 0.6%) and 7.7 and 0.3% after IUI-D (in 2013: 7.5 and 0.3%). The method of data collection and reporting varies among European countries. The EIM receives aggregated data from various countries with variable levels of completeness. Registries from a number of countries have failed to provide adequate data about the number of initiated cycles and deliveries. As long as incomplete data are provided, the results should be interpreted with caution. The 18th ESHRE report on ART shows a continuing expansion of treatment numbers in Europe. The number of treatments reported, the variability in treatment modalities and the rising contribution to the birth rates in most participating countries point towards the increasing impact of ART on reproduction in Europe. Being the largest data collection on ART, the report gives detailed information about ongoing developments in the field. The study has no external funding and all costs are covered by ESHRE. There are no competing interests.

The 14th European IVF—monitoring (EIM) report presents the results of medically assisted reproduction treatments including assisted reproductive technology (ART) cycles and intrauterine insemination (IUI) cycles initiated in Europe during 2010: are there changes in the trends compared with previous years? Despite some fluctuations in the number of countries reporting, the overall number of ART cycles has continued to increase year by year, and while pregnancy rates in 2010 remained similar to those reported in 2009, the number of transfers with multiple embryos (three or more) further declined. Since 1997, ART data in Europe have been collected and reported in 13 manuscripts, published in Human Reproduction. Retrospective collection of European ART data by the EIM Consortium for ESHRE; data were collected from cycles started between 1st January and 31st December 2010 by the National Registries of individual European countries, or on a voluntary basis by personal information for European countries without a national registry. Out of 31 countries, 991 clinics reported 550 296 ART treatment cycles: IVF (125 994), ICSI (272 771), frozen embryo replacement (FER, 114 593), egg donation (ED, 25 187), in vitro maturation (493), preimplantation genetic diagnosis/preimplantation genetic screening (6399) and frozen oocyte replacements (4859). European data on IUI using husband/partner's semen (IUI-H) or donor semen (IUI-D) were reported from 22 and 19 countries, respectively. A total of 176 512 IUI-H (+8.4% compared with 2009) and 38 124 IUI-D (+30.4% compared with 2009) cycles were included. In 16 countries where all clinics reported to the national ART registry, a total of 267 120 ART cycles were performed in a population of 219 million inhabitants, corresponding to 1221 cycles per million inhabitants. For IVF, the clinical pregnancy rates per aspiration and per transfer increased to 29.2 and 33.2%, respectively, and for ICSI, the corresponding rates also increased to 28.8 and 32.0%, when compared with the rates of 2009. In FER cycles, the pregnancy rate per thawing was 20.3%; in ED cycles the pregnancy rate per fresh transfer was 47.4% and per thawed transfer 33.3%. The delivery rate after IUI-H was 8.9 and 13.8% after IUI-D. In IVF and ICSI cycles, one, two, three and four or more embryos were transferred in 25.7, 56.7, 16.1 and 1.5%, respectively. The proportions of singleton, twin and triplet deliveries after IVF and ICSI (combined) were 79.4, 19.6 and 1.0%, respectively, resulting in a total multiple delivery rate of 20.6% compared with 20.2% in 2009, 21.7% in 2008, 22.3% in 2007, 20.8% in 2006. In FER cycles, the multiple delivery rate was 12.8% (12.5% twins and 0.3% triplets). Twin and triplet delivery rates associated with IUI cycles were 9.6/0.5 and 8.5/0.2%, following treatment with husband and donor semen, respectively. The method of reporting is not standardized in Europe but varies among countries. Furthermore registries from a number of countries have been unable to provide some of the relevant data such as initiated cycles and deliveries. Therefore, results should be interpreted with caution. The 14th ESHRE report on ART and IUI treatments shows a continuing expansion of the number of ART treatment cycles in Europe, with more than half a million of cycles reported in 2010. The use of ICSI may have reached a plateau. When compared with 2009/2008, pregnancy and (multiple) delivery rates after IVF and ICSI remained relatively stable. The number of multiple embryo transfers (three or more embryos) has shown a decline. The study has no external funding; all costs are covered by ESHRE. There are no competing interests.

Are there any changes in the treatments involving ART and IUI initiated in Europe during 2013 compared with previous years? An increase in the overall number of ART cycles resulting from a higher number of countries reporting data was evident, the pregnancy rates (PRs) in 2013 remained stable compared with those reported in 2012, the number of transfers with multiple embryos (3+) was lower than ever before yet the multiple delivery rates (DRs) remained unchanged, and IUI activity and success rates were similar to those of last years. Since 1997, ART data in Europe have been collected and reported in 16 manuscripts, published in Human Reproduction. Retrospective data collection of European ART data by the European IVF-monitoring Consortium for ESHRE. Data for cycles between 1 January and 31 December 2013 were collected from National Registers, when existing, or on a voluntary basis by personal information. From 38 countries (+4 compared with 2012), 1169 clinics reported 686 271 treatment cycles including 144 299 of IVF, 330 367 of ICSI, 154 712 of frozen embryo replacement (FER), 40 244 of egg donation (ED), 247 of IVM, 9791 of PGD/PGS and 6611 of frozen oocyte replacements. European data on intrauterine insemination using husband/partner's semen (IUI-H) and donor semen (IUI-D) were reported from 1095 IUI labs in 22 countries. A total of 175 467 IUI-H and 43 785 IUI-D cycles were included. In 17 countries where all clinics reported to their ART register, a total of 374 177 ART cycles were performed in a population of around 310 million inhabitants, corresponding to 1175 cycles per million inhabitants (range, 235–2703 cycles per million inhabitants). For all IVF cycles, the clinical PRs per aspiration and per transfer were stable with 29.6% (29.4% in 2012) and 34.5% (33.8% in 2012), respectively. For ICSI, the corresponding rates also were stable with 27.8% (27.8% in 2012) and 32.9% (32.3% in 2012). In FER-cycles, the PR per thawing/warming increased to 27.0% (23.1% in 2012). In ED cycles, the PR per fresh transfer increased to 49.8% (48.4% in 2012), to 38.5% (35.9% in 2012) per thawed transfer, and to 46.4% for transfers after FOR (45.1% in 2012). The DRs after IUI remained stable at 8.6% (8.5% in 2012) after IUI-H and was slightly lower after IUI-D (11.1% versus 12.0% in 2012). In IVF and ICSI cycles, 1, 2, 3 and 4+ embryos were transferred in 31.4, 56.3, 11.5, and 1.0% of the cycles, respectively (corresponding numbers were 30.2, 55.4, 13.3 and 1.1% in 2012). The proportions of singleton, twin and triplet deliveries after IVF and ICSI (added together) were 82., 17.5 and 0.5%, respectively, resulting in a total multiple DR of 18.0% compared to 17.9% in 2012. In FER-cycles, the multiple DR was 12.8% (12.5% twins and 0.3% triplets), nearly the same as in 2012 (12.5, 12.2 and 0.3% respectively). Twin and triplet DRs associated with IUI cycles were 9.5%/0.6% and 7.5%/0.3%, following treatment with husband/donor semen, respectively. The method of reporting varies among countries, and registers from a number of countries have been unable to provide some of the relevant data such as initiated cycles and deliveries. As long as data are incomplete and generated through different methods of collection, the results should be interpreted with caution. The 17th ESHRE report on ART shows a continuing expansion of the number of treatment cycles in Europe, with more than 685 000 cycles reported in 2013 and an increasing contribution to birth rate in many countries. However, the need to improve and standardize the national registries, and to establish validation methodologies, remains manifest. The study has no external funding; all costs are covered by ESHRE. There are no competing interests.

What are the European trends and developments in ART and IUI in 2015 as compared to previous years? The 19th ESHRE report on ART shows a continuing expansion of treatment numbers in Europe, and this increase, the variability in treatment modalities and the rising contribution to the birth rates in most participating countries all point towards the increasing impact of ART on European society. Since 1997, the ART data generated by national registries have been collected, analysed and reported in 18 manuscripts published in Human Reproduction. Collection of European data by the European IVF-Monitoring Consortium (EIM) for ESHRE. The data for treatments performed between 1 January and 31 December 2015 in 38 European countries were provided by national registries or on a voluntary basis by clinics or professional societies. From 1343 institutions in 38 countries offering ART services a total of 849 811 treatment cycles, involving 155 960 with IVF, 385676 with ICSI, 218098 with frozen embryo replacement (FER), 21 041 with preimplantation genetic testing (PGT), 64 477 with egg donation (ED), 265 with IVM and 4294 with FOR were recorded. European data on IUI using husband/partner’s semen (IUI-H) and donor semen (IUI-D) were reported from 1352 institutions offering IUI in 25 countries and 21 countries, respectively. A total of 139 050 treatments with IUI-H and 49 001 treatments with IUI-D were included. In 18 countries (14 in 2014) with a population of approximately 286 million inhabitants, in which all institutions contributed to their respective national registers, a total of 409 771 treatment cycles were performed, corresponding to 1432 cycles per million inhabitants (range: 727–3068 per million). After IVF the clinical pregnancy rates (PRs) per aspiration and per transfer were slightly lower in 2015 as compared to 2014, at 28.5 and 34.6% versus 29.9 and 35.8%, respectively. After ICSI, the corresponding PR achieved per aspiration and per transfer in 2015 were also slightly lower than those achieved in 2014 (26.2 and 33.2% versus 28.4 and 35.0%, respectively). On the other hand, after FER with own embryos the PR per thawing continued to rise from 27.6% in 2014 to 29.2% in 2015. After ED a slightly lower PR per embryo transfer was achieved: 49.6% per fresh transfer (50.3% in 2014) and 43.4% for FOR (48.7% in 2014). The delivery rates (DRs) after IUI remained stable at 7.8% after IUI-H (8.5% in 2014) and at 12.0% after IUI-D (11.6% in 2014). In IVF and ICSI together, 1, 2, 3 and ≥4 embryos were transferred in 37.7, 53.9, 7.9 and in 0.5% of all treatments, respectively (corresponding to 34.9, 54.5, 9.9 and in 0.7% in 2014). This evolution towards the transfer of fewer embryos in both IVF and ICSI resulted in a proportion of singleton, twin and triplet DR of 83.1, 16.5 and 0.4%, respectively (compared to 82.5, 17.0 and 0.5%, respectively, in 2014). Treatments with FER in 2015 resulted in twin and triplet DR of 12.3 and 0.3%, respectively (versus 12.4 and 0.3% in 2014). Twin and triplet delivery rates after IUI-H were 8.9 and 0.5%, respectively (in 2014: 9.5 and 0.3%), and 7.3 and 0.6% after IUI-D (in 2014: 7.7 and 0.3%). The methods of data collection and reporting vary among European countries. The EIM receives aggregated data from various countries with variable levels of completeness. Registries from a number of countries have failed to provide adequate data about the number of initiated cycles and deliveries. As long as incomplete data are provided, the results should be interpreted with caution. The 19th EIM report on ART shows a continuing expansion of treatment numbers in Europe. The number of treatments reported, the variability in treatment modalities and the rising contribution to the birth rates in most participating countries point towards the increasing impact of ART on reproduction in Europe. Being the largest data collection on ART worldwide, detailed information about ongoing developments in the field is provided. The study has no external funding and all costs are covered by ESHRE. There are no competing interests.

BACKGROUND: In 2020, SARS-CoV-2 and the COVID-19 pandemic had a huge impact on the access to and provision of ART treatments. Gradually, knowledge of the virus and its transmission has become available, allowing ART activities to resume. Still, questions on the impact of the virus on human gametes and fertility remain. OBJECTIVE AND RATIONALE: This article summarizes published data, aiming to clarify the impact of SARS-CoV-2 and the COVID-19 disease on human fertility and assisted reproduction, as well as the impact of vaccination, and from this, provide answers to questions that are relevant for people contemplating pregnancy and for health care professionals. SEARCH METHODS: PUBMED/MEDLINE and the WHO COVID-19 database were searched from inception to 5 October 2022 with search terms focusing on ‘SARS-CoV-2’ and gametes, embryos, reproductive function, fertility and ART. Non-English studies and papers published prior to 2020 were excluded, as well as reviews and non-peer reviewed publications. Full papers were assessed for relevance and quality, where feasible. OUTCOMES: From the 148 papers included, the following observations were made. The SARS-CoV-2-binding proteins, angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine protease (TMPRSS2), are expressed in the testis, but co-expression remains to be proven. There is some evidence of SARS-CoV-2 RNA in the ejaculate of COVID-19 patients with severe disease, but not in those with mild/moderate disease. SARS-CoV-2 infection can impair spermatogenesis, but this seems to resolve after one spermatogenic cycle. Testosterone levels seem to be lower during and after COVID-19, but long-term data are lacking; disease severity may be associated with testosterone levels. COVID-19 cannot be considered a sexually transmitted disease. There is no co-expression of ACE2 and TMPRSS2 in the myometrium, uterus, ovaries or fallopian tubes. Oocytes seem to have the receptors and protease machinery to be susceptible to SARS-CoV-2 infection; however, viral RNA in oocytes has not been detected so far. Women contemplating pregnancy following COVID-19 may benefit from screening for thyroid dysfunction. There is a possible (transient) impact of COVID-19 on menstrual patterns. Embryos, and particularly late blastocysts, seem to have the machinery to be susceptible to SARS-CoV-2 infection. Most studies have not reported a significant impact of COVID-19 on ovarian reserve, ovarian function or follicular fluid parameters. Previous asymptomatic or mild SARS-CoV-2 infection in females does not seem to negatively affect laboratory and clinical outcomes of ART. There are no data on the minimum required interval, if any, between COVID-19 recovery and ART. There is no evidence of a negative effect of SARS-CoV-2 vaccination on semen parameters or spermatogenesis, ovarian function, ovarian reserve or folliculogenesis. A transient effect on the menstrual cycle has been documented. Despite concerns, cross reactivity between anti-SARS-CoV-2 spike protein antibodies and Syncytin-1, an essential protein in human implantation, is absent. There is no influence of mRNA SARS-CoV-2 vaccine on patients’ performance during their immediate subsequent ART cycle. Pregnancy rates post-vaccination are similar to those in unvaccinated patients. WIDER IMPLICATIONS: This review highlights existing knowledge on the impact of SARS-CoV-2 infection or COVID-19 on fertility and assisted reproduction, but also identifies gaps and offers suggestions for future research. The knowledge presented should help to provide evidence-based advice for practitioners and couples contemplating pregnancy alike, facilitating informed decision-making in an environment of significant emotional turmoil.

Background: Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of Assisted Reproductive Technology (ART) treatment. The objective of this study was to assess the odds of OHSS hospital admission in relation to oestradiol levels on day of hCG administration and number of oocytes collected. Methods: We performed a 24 months retrospective analysis of a cohort of patients receiving ART treatment in a University teaching hospital including all patients requiring admission due to OHSS. Main outcome measures were oestradiol levels, number of oocytes collected and incidence of admission with OHSS. Results: OHSS requiring admission to hospital occurred in 1.8% of cases. While no patients with an oestradiol level at hCG ≤15,000 pmol/L developed OHSS, those with oestradiol levels ≥15,000 pmol/L had different risks of admission according to the number of oocytes collected: those with >30 oocytes were 6.7 times more likely to be admitted that those with <20 oocytes. Conclusions: This study identifies an oestradiol level (≥15,000 pmol/L) and number of oocytes (≥20) above which the odds of being admitted with OHSS increases significantly. Although OHSS cannot always be prevented, these measurable parameters should be used to allow appropriate counselling and subsequent safe management of ART patients.