BMAL1 positively correlates with genes regulating steroidogenesis in human luteinized granulosa cells.

In brief: In this study, we examined the relationship between BMAL1 expression and the genes regulating steroid biosynthesis in human luteinized granulosa cells. BMAL1 function is crucial for steroid production and proper ovarian function, highlighting the importance of circadian clock regulation in female reproductive health. Abstract: Human luteinized granulosa cells were collected to analyze circadian clock gene expression and its effect on the genes regulating steroid biosynthesis. We used siRNA to knock down the expression of BMAL1 in KGN cells. We measured the expression levels of genes regulating steroid biosynthesis and circadian clock RT-qPCR. We demonstrated that BMAL1 expression positively correlates with genes regulating steroid biosynthesis (CYP11A1, CYP19A1, STAR, and ESR2). The knockdown of BMAL1 in KGN cells revealed a significant decrease in steroid synthase expression. In contrast, when BMAL1 was overexpressed in KGN and HGL5 cells, we observed a significant increase in the expression of steroid synthases, such as CYP11A1 and CYP19A1. These results indicated that BMAL1 positively controls 17ß-estradiol (E2) secretion in granulosa cells. We also demonstrated that dexamethasone synchronization in KGN cells enhanced the rhythmic alterations in circadian clock genes. Our study suggests that BMAL1 plays a critical role in steroid biosynthesis in human luteinized granulosa cells, thereby emphasizing the importance of BMAL1 in the regulation of reproductive physiology.

Survey on the implementation status and reproductive outcomes of oocyte and ovarian tissue cryopreservation in Japan: Historical comparison with nationwide surveys.

PURPOSE: To clarify the reproductive outcomes of fertility preservation (FP) treatment. METHODS: We conducted a mailed-in questionnaire survey at institutions certified by the Japan Society of Obstetrics and Gynecology to investigate the number of oocyte cryopreservations (OC) and ovarian tissue cryopreservations (OTC) performed from December 2016 to the end of 2020. And, we conducted a detailed investigation of cases in which frozen specimens were used during the investigation period, and made historical comparisons with previous nationwide studies. RESULTS: Responses were received from 114 out of 150 facilities (response rate: 76.0%) for OC and 43 out of 51 for OTC (response rate: 84.3%). Breast cancer was the most common disease among patients whose FP specimens were used. During the study period, 1237 OCs and 198 OTCs were performed. In addition, 57 cycles of embryo transfer (ET) using cryopreserved oocytes and 12 cases of ovarian tissue transplantation (OTT) were performed. The mean age of patients who underwent ET using cryopreserved oocytes was 34.8 (±5.8) years, with a median age of 36 years. The pregnancy rate per ET using cryopreserved oocytes was 26.3% and the live birth rate (LBR) was 17.5%. Further, the LBR per patient was 43.3%, and the pregnancy rate following OTTs was 33.3%. Also, controlled ovarian stimulation using the random start method or the combination of aromatase inhibitors had no effect on pregnancy outcome. CONCLUSION: Implementation of both OCs and OTCs have markedly increased over time in Japan, with comparable reproductive outcomes as other reports.

Retrospective comparative study of robot-assisted surgery, laparoscopic surgery, and laparotomy for endometrial cancer in patients with a low risk of recurrence.

AIM: Minimally invasive surgeries for endometrial cancer are increasing worldwide. In Japan, some articles have examined surgical outcomes, but only a few have addressed oncological outcomes. This study aims to compare robot surgery, laparoscopic surgery, and laparotomy in terms of surgical and oncological outcomes within a low-risk group for endometrial cancer recurrence. METHODS: This study included patients with endometrial cancer deemed to be at low risk of recurrence and who underwent surgery between January 2011 and December 2020. We studied 99 patients who underwent robot surgery, 85 patients who underwent laparotomy, and 77 patients who underwent laparoscopic surgery. Surgical and oncological outcomes were compared retrospectively for these groups of patients. RESULTS: The median follow-up period was 47, 61, and 60 months in the laparotomy, laparoscopy, and robotic groups, respectively. The three groups had similar perioperative and pathological data. No significant differences in overall survival and disease-free survival were observed among the groups. Univariate and multivariate analyses conducted on the overall study population for disease-free survival and overall survival showed that the surgical approach did not have any influence. Minimally invasive surgery groups had longer operating times compared to the laparotomy group, but they had significantly less blood loss. The number of resected pelvic lymph nodes was similar, and the complication rate was not significant. CONCLUSIONS: Robot-assisted surgery and laparoscopic surgery were found to be less invasive and showed similar oncologic outcomes compared to laparotomy surgery for endometrial cancer in patients with a low risk of recurrence.

A nationwide survey of diagnostic procedures for abnormal uterine bleeding in Japan.

AIM: To clarify the diagnostic process of the causative disease of abnormal uterine bleeding (AUB) in Japan according to the International Federation of Gynecology and Obstetrics AUB diagnostic system. METHODS: Patients diagnosed with AUB were included in a nationwide survey of AUB conducted during any 2-week period between December 2019 and January 2020. The second survey included information on patient background, AUB symptoms, examinations for diagnosing AUB, the order in which they were performed, and the causative diseases of AUB. RESULTS: Correspondence analysis showed an association between hormonal testing, hysterosalpingography, and magnetic resonance imaging (MRI) in patients with amenorrhea, and heavy menstrual bleeding was strongly correlated with various examinations, such as coagulation tests, pelvic MRI, and endometrial cytology or biopsy. The results also indicated that each AUB causative disease can be diagnosed based on a specific examination profile. CONCLUSION: We clarified the process of diagnosing the causative disease of AUB in our country and determined that it was mainly diagnosed by imaging and pathological examination in cases of structural disease. The high rate of AUB-E and the low rate of AUB-C are possibly associated with specific examination trends in Japan. The results of this study will be useful for the development of a standard protocol for AUB diagnosis in our country.

Reproductive outcomes of embryo cryopreservation and transfer at the start-up phase of fertility preservation in Japan.

Purpose: To verify the effectiveness of embryo transfer (ET) using cryopreserved embryo as fertility preservation (FP). Methods: This study was a questionnaire survey. The total number of embryo cryopreservation (EC) was investigated between 2014 and 2020. And for patients who underwent ET among study period, details of EC, outcome of ET, number of live births, and mortality were investigated. Results: Of the 150 facilities, 114 responded (76.0%). A total of 1420 EC were performed during the study period; and ET was performed for 417 patients. Breast cancer was the most common primary disease. A total of 199 live births (including prospective) were obtained by ET; 1.7 EC and 2.2 ET were performed per patient, and live birth rate was 21.4% per ET (28.1% on 35-37-year-old patients). The number of EC and ET increased with age. The final birth rate, including pregnancies other than FP, was 51.8%. Ovarian stimulation with aromatase inhibitors was commonly used, although with no effect on live birth rates. Random start stimulation was also common, experienced by 36.3% of breast cancer patients. Conclusion: Reproductive outcomes of ETs following EC as FP are acceptable. This research project was registered in the University Hospital Medical Information Network (UMIN000043664).

[Ovarian hyperstimulation syndrome with controlled ovarian stimulation after induction therapy for Philadelphia chromosome-positive acute lymphoblastic leukemia].

A 27-year-old woman with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia received induction therapy with dasatinib and prednisolone. From the time of diagnosis, oocyte storage was planned in accordance with the patient's wishes. After progesterone administration for suppression of menstruation, and blood cell recovery, ovarian stimulation was performed and a sufficient number of eggs was collected. The patient was considered at high risk for ovarian stimulation syndrome (OHSS) and received cabergoline and letrozole. However, ovarian enlargement and ascites were observed on ultrasonography 2 days after egg collection, and a diagnosis of moderate OHSS was made. Circulatory management was performed and low-molecular-weight heparin was administered. Dasatinib was discontinued due to the appearance of pleural effusion. Fluid retention improved after menstruation resumed, and the patient was able to continue consolidation with dasatinib and cord blood transplantation. Although tyrosine kinase inhibitors are expected to simplify planning of oocyte storage, the risk of complicating OHSS should be noted.

Desynchronization between Food Intake and Light Stimulations Induces Uterine Clock Quiescence in Female Mice.

BACKGROUND: Dysmenorrhea is associated with breakfast skipping in young women, suggesting that fasting in the early active phase disrupts uterine functions. OBJECTIVES: To investigate the possible involvement of the uterine clock system in fasting-induced uterine dysfunction, we examined core clock gene expressions in the uterus using a 28-h interval-fed mouse model. METHODS: Young female mice (8 wk of age) were divided into 3 groups: group I (ad libitum feeding), group II (time-restricted feeding, initial 4 h of the active period every day), and group III (time-restricted feeding for 8 h with a 28-h cycle). Groups II and III have the same fasting interval of 20 h. After analyzing feeding and wheel running behaviors during 2 wk of dietary restriction, mice were sacrificed at 4-h intervals, and the expression profiles of clock genes in the uterus and liver were examined by qPCR. RESULTS: The mice in group I took food mainly during the dark phase and those in group II during the initial 4 h of the dark phase, whereas those in group III delayed feeding time by 4 h per cycle. In all groups, spontaneous wheel running was observed during the dark phase. There was no difference in the quantity of feeding and the amount of running exercise among the 3 groups during the second week. The mRNA expressions of peripheral clock genes, Bmal1, Clock, Per1, Per2, Cry1, Nr1d1, and Dbp and a clock-controlled gene, Fabp1, in the uterus showed rhythmic oscillations with normal sequential expression cascade in groups I and II, whereas their expressions decreased and circadian cycles disappeared in group III. In contrast, liver core clock genes in group III showed clear circadian cycles. CONCLUSIONS: Fluctuations in the timing of the first food intake impair the uterine clock oscillator system to reduce clock gene expressions and abolish their circadian rhythms.

Imeglimin profoundly affects the circadian clock in mouse embryonic fibroblasts.

OBJECTIVE: Imeglimin is a novel antidiabetic drug structurally related to metformin. Metformin has been shown to modulate the circadian clock in rat fibroblasts. Accordingly, in the present study, we aimed to determine whether imeglimin can impact the circadian oscillator in mouse embryonic fibroblasts (MEFs). METHODS: MEFs carrying a Bmal1-Emerald luciferase (Bmal1-ELuc) reporter were exposed to imeglimin (0.1 or 1 mM), metformin (0.1 or 1 mM), a nicotinamide phosphoribosyltransferase inhibitor FK866, and/or vehicle. Subsequently, Bmal1-ELuc expression and clock gene mRNA expression levels were measured at 10-min intervals for 55 h and 4-h intervals for 32 h, respectively. RESULTS: Imeglimin significantly prolonged the period (from 26.3 to 30.0 h at 0.1 mM) and dose-dependently increased the amplitude (9.6-fold at 1 mM) of the Bmal1-ELuc expression rhythm; however, metformin exhibited minimal effects on these parameters. Moreover, imeglimin notably impacted the rhythmic mRNA expression of clock genes (Bmal1, Per1, and Cry1). The concurrent addition of FK866 partly inhibited the effects of imeglimin on both Bmal1-ELuc expression and clock gene mRNA expression. CONCLUSION: Collectively, these results reveal that imeglimin profoundly affects the circadian clock in MEFs. Further studies are needed to evaluate whether imeglimin treatment could exert similar effects in vivo.

Effect of a web-based fertility preservation training program for medical professionals in Japan.

BACKGROUND: Our web-based training program called "Educating Medical Professionals about Reproductive Issues in Cancer Healthcare" aims to help healthcare professionals communicate promptly with patients and survivors who are adolescents and young adults, with information pertinent to reproductive health issues such as the risk of infertility and fertility preservation. METHODS: The study participants were professional healthcare providers, including physicians, nurses, pharmacists, social workers, midwives, psychologists, laboratory technicians, genetic counselors, and dieticians. Pre- and post- and 3-month follow-up tests consisting of 41 questions were administered to measure changes in knowledge and confidence. The participants also received a follow-up survey that covered confidence, communication techniques, and practice habits. A total of 820 healthcare providers participated in this program. RESULTS: The mean total score from the pre-test to the post-test grew significantly (p < 0.01), and participants' self-confidence increased. In addition, there was a change in the behavior of healthcare providers, who began asking about patients' marital status and parity. CONCLUSION: Our web-based fertility preservation training program improved knowledge and self-confidence regarding fertility preservation issues among healthcare providers caring for adolescents and young adult cancer patients and survivors.

Text mining in a literature review of abnormal uterine bleeding according to the FIGO classification.

AIM: Abnormal uterine bleeding, as proposed in 2007, is defined as unexpected uterine bleeding in women of reproductive age; the cause of the bleeding is categorized using the PALM-COEIN system. Identifying the diagnostic and treatment modalities for each cause might be intriguing. To summarize the options for abnormal uterine bleeding assessment, we employed text-mining analysis for each of its causes. METHODS: We analyzed abstracts based on PALM-COEIN from PubMed and Web of Science in March 2022. The literature was divided into categories; topics about the disorders were retrieved, and covalent network analysis was conducted to find information for evaluating abnormal uterine bleeding. RESULTS: Diagnostic approaches for PALM included histological and image analysis, including computerized tomography, magnetic resonance imaging, sonography, and hysteroscopy. The therapeutic approaches varied according to the cause. Diagnostic approaches for COEIN were mostly medical history interviews and blood sampling, and the therapeutic approaches for COEIN were ablation, hysteroscopy, and hormonal treatment. The PALM-COEIN classification co-occurrence search revealed each cause's diagnostic procedures, symptoms, and treatment procedures. CONCLUSION: Our text-mining methodology revealed comprehensive insights, important study themes, and clinical trends for abnormal uterine bleeding. A tailored approach to medical realities is required for treating abnormal uterine bleeding properly.

National survey of abnormal uterine bleeding according to the FIGO classification in Japan.

AIM: To investigate the status of abnormal uterine bleeding (AUB) in Japan using the International Federation of Gynecology and Obstetrics (FIGO) classification (AUB system 1 and 2; PALM-COEIN) and to clarify the relationship between AUB symptoms and the diseases causing AUB. METHODS: In a nationwide study, we enrolled first-time patients who visited target facilities during two consecutive weeks from December 1, 2019 to January 31, 2020. The FIGO classification was used to investigate patients with symptoms and causative diseases of AUB. Based on the proportion of patients in the nationwide study, 373 cases were included in the detailed survey. Survey items included symptoms of AUB according to AUB system 1, examination details, and causative diseases according to the PALM-COEIN classification. RESULTS: Within the study period, we encountered 61 740 first-time patients, of which 8081 (13.1%) were diagnosed with AUB. Among them, 39.9% had abnormal menstrual cycles and 56.9% had abnormal menstrual bleeding. In the survey, PALM had the highest percentage of AUB-L and COEIN had the highest percentage of AUB-O. Correspondence analysis showed that COEIN was strongly associated with abnormal menstrual cycles and PALM with abnormal menstrual bleeding. CONCLUSION: We conducted the first nationwide survey of AUB in Japan. The FIGO classification was a useful tool for the diagnosis of AUB, with a strong correlation between symptoms of AUB by AUB system 1 and the causative disease of AUB by PALM-COEIN. Conversely, a high percentage of AUB-N and AUB-E suggests that AUB system 1 and PALM-COEIN are ambiguous as diagnostic tools.

The Circadian Clock, Nutritional Signals and Reproduction: A Close Relationship.

The circadian rhythm, which is necessary for reproduction, is controlled by clock genes. In the mouse uterus, the oscillation of the circadian clock gene has been observed. The transcription of the core clock gene period (Per) and cryptochrome (Cry) is activated by the heterodimer of the transcription factor circadian locomotor output cycles kaput (Clock) and brain and muscle Arnt-like protein-1 (Bmal1). By binding to E-box sequences in the promoters of Per1/2 and Cry1/2 genes, the CLOCK-BMAL1 heterodimer promotes the transcription of these genes. Per1/2 and Cry1/2 form a complex with the Clock/Bmal1 heterodimer and inactivate its transcriptional activities. Endometrial BMAL1 expression levels are lower in human recurrent-miscarriage sufferers. Additionally, it was shown that the presence of BMAL1-depleted decidual cells prevents trophoblast invasion, highlighting the importance of the endometrial clock throughout pregnancy. It is widely known that hormone synthesis is disturbed and sterility develops in Bmal1-deficient mice. Recently, we discovered that animals with uterus-specific Bmal1 loss also had poor placental development, and these mice also had intrauterine fetal death. Furthermore, it was shown that time-restricted feeding controlled the uterine clock's circadian rhythm. The uterine clock system may be a possibility for pregnancy complications, according to these results. We summarize the most recent research on the close connection between the circadian clock and reproduction in this review.

Assisted reproductive technology in Japan: A summary report for 2020 by the ethics Committee of the Japan Society of obstetrics and gynecology.

Purpose: Since 1986, the Japan Society of Obstetrics and Gynecology assisted reproductive technology (ART) registry system has collected data on national ART use and outcomes trends in Japan. Herein, we describe the characteristics and outcomes of ART cycles registered during 2020 and compare the results with those from 2019. Methods and Results: In 2020, 621 ART facilities participated in the registration. The total number of registered cycles was 449 900, and there were 60 381 live births, which decreased from the previous year (1.79% and 0.36% decrease, respectively). The number of freeze-all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles increased in 2020, and the number of neonates born was 2282 for IVF-embryo transfer (ET) cycles and 2596 for ICSI cycles, which had decreased from the previous year. Frozen-thawed ET (FET) cycles had slightly increased from 2019 (0.04%). In 2020, 215 285 FET cycles were conducted, resulting in 76 196 pregnancies and 55 503 neonates. Single ET was performed in 81.6% of fresh transfers and 85.1% of frozen-thawed cycles, respectively, resulting in over 97% singleton pregnancies/livebirths rates. Conclusion: Despite the COVID-19 pandemic during 2020, the overall number of ART cycles and neonates born demonstrated only a slight decrease in 2020 compared with 2019.

FOXP4 inhibits squamous differentiation of atypical cells in cervical intraepithelial neoplasia via an ELF3-dependent pathway.

Although the human papillomavirus (HPV) vaccine is effective for preventing cervical cancers, this vaccine does not eliminate pre-existing infections, and alternative strategies have been warranted. Here, we report that FOXP4 is a new target molecule for differentiation therapy of cervical intraepithelial neoplasia (CIN). An immunohistochemical study showed that FOXP4 was expressed in columnar epithelial, reserve, and immature squamous cells, but not in mature squamous cells of the normal uterine cervix. In contrast with normal mature squamous cells, FOXP4 was expressed in atypical squamous cells in CIN and squamous cell carcinoma lesions. The FOXP4-positive areas significantly increased according to the CIN stages from CIN1 to CIN3. In monolayer cultures, downregulation of FOXP4 attenuated proliferation and induced squamous differentiation in CIN1-derived HPV 16-positive W12 cells via an ELF3-dependent pathway. In organotypic raft cultures, FOXP4-downregulated W12 cells showed mature squamous phenotypes of CIN lesions. In human keratinocyte-derived HaCaT cells, FOXP4 downregulation also induced squamous differentiation via an ELF3-dependent pathway. These findings suggest that downregulation of FOXP4 inhibits cell proliferation and promotes the differentiation of atypical cells in CIN lesions. Based on these results, we propose that FOXP4 is a novel target molecule for nonsurgical CIN treatment that inhibits CIN progression by inducing squamous differentiation.

Indications for fertility preservation not included in the 2017 Japan Society of Clinical Oncology Guideline for Fertility Preservation in Pediatric, Adolescent, and Young Adult Patients treated with gonadal toxicity, including benign diseases.

In recent years, local governments in Japan have established a public financial support system for fertility preservation in pediatric, adolescent, and young adult cancer patients. Fertility preservation has become popular for patients with cancers included in the gonadal toxicity risk classification of the 2017 edition of the Guideline for Fertility Preservation in Children, Adolescents and Young Adult Cancer Patients from the Japan Society of Clinical Oncology. However, patients with cancer and non-cancer diseases that are not included in the Guideline's gonadal toxicity risk classification also often receive treatment that may affect fertility, but they are often denied the opportunity of fertility preservation because no public financial support is available for diseases not listed in the Guideline. The national research project proposes including these diseases in the indications and treatment for fertility preservation. Therefore, we cooperated with the Japan Society for Fertility Preservation and the Ministry of Health, Labour and Welfare research group to solicit opinions from experts in each therapeutic area and reviewed the literature and overseas guidelines. This paper summarizes the findings of the project. We believe that it will be an important source of information for clinicians treating patients who need fertility preservation but note that the appropriateness of fertility preservation for the disorders listed in this report needs to be continuously reviewed as medical care advances.

Case-based survey: The impact of breast-cancer treatment on fertility in Japan.

AIM: To assess the impact of breast-cancer treatment on fertility. METHODS: We conducted a retrospective, case-based survey of treatments administered for infertility and pregnancy outcomes after patients underwent treatment for breast cancer. Surveys were distributed to breast oncology facilities and reproductive endocrinology and infertility (REI) facilities. RESULTS: As high as 60% of the pregnancies in women under the age of 35 years occurred spontaneously. Additionally, the fertility rates decreased as age increased (under 35 years of age: 40%, 35-39 years of age: 21%, 40-44 years of age: 10%, respectively). In women who became pregnant after treatment for breast cancer, conception was achieved within 1 to 3 years after beginning to try for pregnancy. CONCLUSIONS: After treatment for breast cancer, women can expect spontaneous pregnancy, especially if they are under 35 years of age. It is important for patients 35 years of age and older to commence assisted reproductive technology in a timely manner when pursuing fertility after treatment for breast cancer.

Human Chorionic Villous Differentiation and Placental Development.

In humans, the placenta provides the only fetomaternal connection and is essential for establishing a pregnancy as well as fetal well-being. Additionally, it allows maternal physiological adaptation and embryonic immunological acceptance, support, and nutrition. The placenta is derived from extra-embryonic tissues that develop rapidly and dynamically in the first weeks of pregnancy. It is primarily composed of trophoblasts that differentiate into villi, stromal cells, macrophages, and fetal endothelial cells (FEC). Placental differentiation may be closely related to perinatal diseases, including fetal growth retardation (FGR) and hypertensive disorders of pregnancy (HDP), and miscarriage. There are limited findings regarding human chorionic villous differentiation and placental development because conducting in vivo studies is extremely difficult. Placental tissue varies widely among species. Thus, experimental animal findings are difficult to apply to humans. Early villous differentiation is difficult to study due to the small tissue size; however, a detailed analysis can potentially elucidate perinatal disease causes or help develop novel therapies. Artificial induction of early villous differentiation using human embryonic stem (ES) cells/induced pluripotent stem (iPS) cells was attempted, producing normally differentiated villi that can be used for interventional/invasive research. Here, we summarized and correlated early villous differentiation findings and discussed clinical diseases.

Uterine Deletion of Bmal1 Impairs Placental Vascularization and Induces Intrauterine Fetal Death in Mice.

Recently, it was demonstrated that the expression of BMAL1 was decreased in the endometrium of women suffering from recurrent spontaneous abortion. To investigate the pathological roles of uterine clock genes during pregnancy, we produced conditional deletion of uterine Bmal1 (cKO) mice and found that cKO mice could receive embryo implantation but not sustain pregnancy. Gene ontology analysis of microarray suggested that uterine NK (uNK) cell function was suppressed in cKO mice. Histological examination revealed the poor formation of maternal vascular spaces in the placenta. In contrast to WT mice, uNK cells in the spongiotrophoblast layer, where maternal uNK cells are directly in contact with fetal trophoblast, hardly expressed an immunosuppressive NK marker, CD161, in cKO mice. By progesterone supplementation, pregnancy could be sustained until the end of pregnancy in some cKO mice. Although this treatment did not improve the structural abnormalities of the placenta, it recruited CD161-positive NK cells into the spongiotrophoblast layer in cKO mice. These findings indicate that the uterine clock system may be critical for pregnancy maintenance after embryo implantation.

Assisted reproductive technology in Japan: A summary report for 2019 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology.

Purpose: The Japan Society of Obstetrics and Gynecology records online annual cycle-based information for assisted reproductive technology (ART). This report presents the characteristics and treatment outcomes of ART cycles registered during 2019. Methods: The Japanese ART registry includes cycle-specific information from 619 participating facilities, including treatment and pregnancy outcomes. Descriptive analyses were conducted for cycles registered during 2019. Results: In 2019, 458 101 treatment cycles and 60 598 neonates were reported, both of which increased from 2018. The number of fresh cycles, including in vitro fertilization and intracytoplasmic sperm injection, decreased, while frozen-thawed embryo transfer (ET) cycles increased. The mean maternal age was 37.9 years (standard deviation ± 4.7). Of 239 348 oocyte retrievals, 123 690 (51.7%) involved freeze-all-embryos cycles; fresh ET was performed in 41 831 cycles (a decreasing trend since 2015). In 2019, there were 211 597 frozen-thawed ET cycles, resulting in 74 882 pregnancies and 54 168 neonates born. Single ET was performed in 82.6% of fresh transfers and 85.1% of frozen-thawed cycles, with singleton live birth rates of 97.3% for both. Conclusions: The number of fresh cycles decreased but frozen cycles increased in 2019. Single ET was performed in >80% of cases, and the proportion of babies born from frozen-thawed ET increased.

Amniotic band syndrome in a monochorionic diamniotic twin pregnancy after rupture of the dividing membrane in the early second trimester: A case report.

BACKGROUND: Amniotic band syndrome is a rare phenomenon, but it can result in serious complications. We report herein our experience of amniotic band syndrome in a monochorionic diamniotic twin pregnancy where rupture of the dividing membrane occurred early in the second trimester. CASE PRESENTATION: A 29-year-old nulliparous woman was referred to us for management of her monochorionic diamniotic twin pregnancy at 10 weeks of gestation. When we were unable to identify a dividing membrane at 15 weeks of gestation using two-dimensional ultrasonography, we used three-dimensional ultrasonography to confirm its absence. Both modalities showed that the left arm of baby B was swollen and attached to a membranous structure originating from the placenta at 18 weeks of gestation. Tangled umbilical cords were noted on magnetic resonance imaging at 18 weeks of gestation. Emergency cesarean delivery was performed at 30 weeks of gestation because of the nonreassuring fetal status of baby A. The left arm of baby B had a constrictive ring with a skin defect. Both neonates had an uncomplicated postnatal course and were discharged around 2 months after delivery. CONCLUSIONS: Attention should be paid to the potential for amniotic band syndrome if rupture of the dividing membrane between twins is noted during early gestation.