Guideline for gynecological practice in Japan: Japan Society of Obstetrics and Gynecology and Japan Association of Obstetricians and Gynecologists 2023 edition.

Twelve years after the first edition of The Guideline for Gynecological Practice, which was jointly edited by The Japan Society of Obstetrics and Gynecology and The Japan Association of Obstetricians and Gynecologists, the 5th Revised Edition was published in 2023. The 2023 Guidelines includes 5 additional clinical questions (CQs), which brings the total to 103 CQ (12 on infectious disease, 30 on oncology and benign tumors, 29 on endocrinology and infertility and 32 on healthcare for women). Currently, a consensus has been reached on the Guidelines, and therefore, the objective of this report is to present the general policies regarding diagnostic and treatment methods used in standard gynecological outpatient care that are considered appropriate. At the end of each answer, the corresponding Recommendation Level (A, B, C) is indicated.

Assisted reproductive technology in Japan: A summary report for 2021 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology.

Purpose: The Japan Society of Obstetrics and Gynecology (JSOG) registry gathers comprehensive data from registered assisted reproductive technology (ART) facilities in Japan. Herein, we report 2021 ART cycle characteristics and outcomes. Methods: Descriptive statistics were used to summarize and analyze 2021 data. Results: In 2021, 625 ART facilities participated in the registry; 27 facilities did not conduct ART cycles and 598 registered treatment cycles. In total, 498 140 cycles were registered, and there were 69 797 neonates (increases of 10.7% and 15.5%, respectively, from the previous year). The number of freeze-all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles decreased in 2021; the number of neonates born was 2268 for IVF-embryo transfer (ET) cycles and 2850 for ICSI cycles. Frozen-thawed ET (FET) cycles increased markedly from 2020 (11.2% increase). In 2021, 239 428 FET cycles were conducted, resulting in 87 174 pregnancies and 64 679 neonates. For fresh transfers, the total single ET, singleton pregnancy rate, and singleton live birth rates were 82.7%, 97.0%, and 97.3%; for FET, these rates were 84.9%, 96.9%, and 97.1%. Conclusions: The 2021 Japanese ART registry analysis showed marked increases in both total treatment cycles and live births from the previous year.

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.

Maternal cell contamination in embryonic chromosome analysis of missed abortions.

AIM: The fetal sample used for embryonic chromosome analysis is often contaminated with maternal cells, making it difficult to evaluate the fetal chromosomes. We examined on the rate of maternal cell contamination and its relationship with maternal information in the embryonic chromosome analysis of missed abortions using the Giemsabanding method. METHODS: Chromosome analysis was performed in 200 cases of delayed miscarriages in first trimester between July 1, 2000 and May 31, 2019. Chorionic villi were collected and were analyzed using the Giemsa banding method. Among the 20 cells for which chromosomal examination was performed, cells wherein 46,XX chromosomes were found together with normal male karyotype or abnormal chromosomes were defined as maternal cell contamination. RESULTS: Of the 200 cases analyzed, 136 had abnormal chromosomes. The normal female karyotype (n = 52) was four times more prevalent than the normal male karyotype (n = 12). Maternal cell contamination was seen in 15.4% of the abnormal chromosome cases and 8.3% of the normal male karyotype cases. There was no significant difference in the gestational age between the contaminated and noncontaminated groups at the time of miscarriage diagnosis. However, miscarriage before fetal heartbeat confirmation was significantly associated with higher maternal cell contamination. CONCLUSION: We found maternal cell contamination in 15% of all the cases. Moreover, in many cases of the normal female karyotype, it was suspected that only maternal chromosomes were cultured. When performing embryonic chromosome analysis in recurrent miscarriages, we should pay attention to maternal cell contamination and interpret the results accordingly.

Upregulated serum granulysin levels in women with antiphospholipid antibody-associated recurrent miscarriage are downregulated by heparin treatment.

Purpose: Granulysin is a cytotoxic protein that simultaneously activates innate and cellular immunity. The authors aimed to evaluate whether granulysin is associated with the antiphospholipid antibody syndrome and whether heparin changes the granulysin levels. Methods: A cohort study was performed with women with antiphospholipid antibody-positive recurrent pregnancy loss (RPL). The authors examined granulysin levels under RPL and evaluated the changes in serum granulysin levels before and 1 week after the commencement of heparin treatment. Results: Serum granulysin levels before heparin treatment were significantly higher in women who tested positive for one or more types of antiphospholipid antibodies (2.75 ± 1.03 vs. 2.44 ± 0.69, p = 0.0341 by Welch's t test), particularly anti-phosphatidylethanolamine antibodies (IgG: 2.98 ± 1.09 vs. 2.51 ± 0.86, p = 0.0013; IgM: 2.85 ± 1.09 vs. 2.47 ± 0.77, p = 0.0024 by Welch's t test). After heparin treatment for 1 week, serum granulysin levels were significantly reduced (p = 0.0017 by the paired t test). The miscarriage rate was significantly higher in women whose serum granulysin levels were not reduced by heparin treatment (p = 0.0086 by Fisher's exact probability test). Conclusion: The results suggest that heparin may reduce the incidence of miscarriage by suppressing serum granulysin levels.

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.

A report on the 73th Annual Congress of the Japan Society of Obstetrics and Gynecology International Workshop for Junior Fellows: Risk-reducing surgery for hereditary breast and ovarian cancer.

At the 73rd Annual Congress of the Japan Society of Obstetrics and Gynecology, young doctors from Japan and South Korea made presentations on the present condition of risk-reducing surgery for hereditary breast and ovarian cancer (RRSO) in their respective country. RRSO was insured in Japan in April 2020, whereas in South Korea, it was insured 7 years earlier in 2013. In Japan, certification criteria have been set for facilities that perform RRSO, and the number of facilities is increasing, but regional disparities still exist in its distribution. The number of gBRCA1/2 testing facilities is larger, and the cost is more affordable in South Korea than in Japan. Additionally, South Korea provides genetic counseling to a wider range of relatives compared to Japan. In the future, as the indications for the gBRCA1/2 test have expanded as a companion diagnostic for the use of PARP inhibitors, it is expected that the number of candidates for the gBRCA1/2 mutation test and RRSO will increase in Japan. It is important to increase the number of BRCA tests while maintaining the quality of genetic counseling in order to provide adequate information on BRCA mutations and RRSO for patients to support their decision. For the development of hereditary breast and ovarian cancer (HBOC) medical care, it is necessary to publish a nationwide database in Japan and continue to analyze and discuss the data based on the results.

Guideline for Gynecological Practice in Japan: Japan Society of Obstetrics and Gynecology and Japan Association of Obstetricians and Gynecologists 2020 edition.

Nine years after the first edition of The Guideline for Gynecological Practice, which was jointly edited by The Japan Society of Obstetrics and Gynecology and The Japan Association of Obstetricians and Gynecologists, the 4th Revised Edition was published in 2020. The 2020 Guidelines includes 4 additional clinical questions (CQ), which brings the total to 99 CQ (12 on infectious disease, 29 on oncology and benign tumors, 29 on endocrinology and infertility and 29 on healthcare for women). Currently, a consensus has been reached on the Guidelines, and therefore, the objective of this report is to present the general policies regarding diagnostic and treatment methods used in standard gynecological outpatient care that are considered appropriate. At the end of each answer, the corresponding Recommendation Level (A, B, C) is indicated.

Assisted reproductive technology in Japan: A summary report for 2018 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology.

PURPOSE: Since 2007, the Japan Society of Obstetrics and Gynecology (JSOG) has collected cycle-based data for assisted reproductive technology (ART) in an online registry. Here, we present the characteristics and treatment outcomes of ART cycles registered during 2018. METHODS: The Japanese ART registry consists of cycle-specific information for all ART treatment cycles implemented at 621 participating facilities. We conducted descriptive analyses for such cycles registered for 2018. RESULTS: In total, 454 893 treatment cycles and 56 979 neonates were reported in 2018: both increased from 2017. The mean maternal age was 38.0 years (standard deviation ± 4.7). Of 247 402 oocyte retrievals, 118 378 (47.8%) involved freeze-all-embryos cycles; fresh embryo transfer (ET) was performed in 50 463 cycles: a decreasing trend since 2015. A total of 199 914 frozen-thawed ET cycles were reported, resulting in 69 357 pregnancies and 49 360 neonates born. Single ET (SET) was performed in 82.2% of fresh transfers and 83.4% of frozen-thawed cycles, with singleton pregnancy/live birth rates of 97.2%/97.2% and 97.0%/97.2%, respectively. CONCLUSIONS: Total ART cycles and subsequent live births increased in 2018. SET was performed in over 80% of cases, and the mode of ET has shifted continuously from using fresh embryos to frozen-thawed ones compared with previous years.

Infertility treatment hinders the careers of working women in Japan.

AIM: Women undergoing infertility treatment often need to balance work and fertility treatment. Therefore, we evaluated the quality of life (QOL) and impact of infertility treatment on Japanese working women and their careers. METHODS: We conducted an online questionnaire at 18 clinics in Japan. Responses were collected from 835 women, 713 of whom were working. The participants were divided into three groups based on treatment stage. Data were collected using the FertiQoL and an original questionnaire created by the authors. The Mann-Whitney U test and a multinomial logistic analysis were used. RESULTS: Approximately 90% of the participants felt that treatment could hinder their work and 8% had quit their jobs. Low QOL was associated with sadness and despair due to infertility and mood disorders, disruptions to life and work, and the complicated medications and procedures involved in treatment. Social isolation and the effect of fertility treatment on daily life and work strongly hindered the careers of working women in the third stage of treatment (in vitro fertilization and intracytoplasmic sperm injection). Approximately 70% of the participants required support to subsidize treatment costs and sought shorter working hours and flextime systems. Only 55% informed their workplaces about the fertility treatment, but about 70% easily gained understanding by informing them. CONCLUSIONS: For many working women, infertility treatment posed barriers to their careers, which could explain the low QOL. Urgent introduction of a support system is necessary in Japan, and understanding and social acceptance of infertility appears to be important.

Assisted reproductive technology in Japan: A summary report for 2017 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology.

PURPOSE: The Japan Society of Obstetrics and Gynecology (JSOG) has collected cycle-based assisted reproductive technology (ART) data in an online registry since 2007. Herein, we present the characteristics and treatment outcomes of ART cycles registered during 2017. METHODS: We collected cycle-specific information for all ART cycles implemented at participating facilities and performed descriptive analysis. RESULTS: In total, 448,210 treatment cycles and 56,617 neonates (1 in 16.7 neonates born in Japan) were reported in 2017, increased from 2016; the number of initiated fresh cycles decreased for the first time ever. The mean patient age was 38.0 years (standard deviation 4.6). A total 110,641 of 245,205 egg retrieval cycles (45.1%) were freeze-all cycles; fresh embryo transfer (ET) was performed in 55,720 cycles. A total 194,415 frozen-thawed ET cycles were reported, resulting in 66,881 pregnancies and 47,807 neonates born. Single ET (SET) was performed in 81.8% of fresh transfers and 83.4% of frozen cycles, with singleton pregnancy/live birth rates of 97.5%/97.3% and 96.7%/96.6%, respectively. CONCLUSIONS: Total ART cycles and subsequent live births increased continuously in 2017, whereas the number of initiated fresh cycles decreased. SET was performed in over 80% of cases, and ET shifted from using fresh embryos to frozen ones.

Is hysteroscopic metroplasty using the incision method for septate uterus a risk factor for adverse obstetric outcomes?

AIM: This study aimed to assess whether hysteroscopic metroplasty using the incision method for septate uterus is a risk factor for adverse obstetric outcomes during pregnancy or delivery. METHODS: This retrospective, single-center cohort study of obstetric complications included 41 patients with recurrent pregnancy loss or unexplained infertility who underwent hysteroscopic metroplasty using the incision method for septate uterus. As controls, we recruited 1139 women who delivered at our hospital during the same period. The primary outcomes were mean weeks of delivery, mean birthweight, rate of cesarean section, rate of breech presentation, rate of post-partum hemorrhage, rate of preterm delivery, rate of placental abruption, rate of placenta previa, rate of placenta accreta and uterine rupture during pregnancy and delivery. RESULTS: The two groups did not differ in terms of age, mean weeks of delivery, mean birthweight, rate of post-partum hemorrhage, rate of preterm delivery, rate of placental abruption, rate of placenta previa or rate of placenta accreta. The rates of cesarean section and breech presentation were significantly higher in the study group than in the control group (56.1 vs 27.7%; P = 0.0002 and 19.5 vs 6.8%; P = 0.007, respectively). There were no cases of uterine rupture during pregnancy or delivery following hysteroscopic metroplasty. CONCLUSION: Hysteroscopic metroplasty using the incision method for septate uterus is not a risk factor for adverse obstetric outcomes. No severe complications, such as placenta abruption, placenta previa, placenta accreta, uterine rupture or heavy hemorrhage, were observed in the postoperative live birth group.

Influence of perinatal low-dose acetylsalicylic acid therapy on fetal hemodynamics evaluated by determining the acceleration-time/ejection-time ratio in the ductus arteriosus.

AIM: Acceleration-time/ejection-time ratio (At/Et ratio) of Doppler waveform is an established hemodynamic parameters that reflect proximal stenosis. Using this parameter, we evaluated whether perinatal low-dose acetylsalicylic acid (ASA) therapy could alter hemodynamics in the ductus arteriosus. METHODS: Pulse Doppler measurements of the fetal ductus arteriosus were performed longitudinally from 20 to 37 gestational weeks in 106 healthy pregnant women (controls) and 65 pregnant women taking daily low-dose ASA (80 or 100 mg/day) because of a history of recurrent pregnancy loss. The At/Et ratio, pulsatility index (PI), and peak systolic velocity were evaluated and statistically analyzed. RESULTS: The At/Et ratio significantly increased with gestational age in both the ASA group (r = 0.54) and the control group (r = 0.35), while the PI did not. Median peak systolic velocities also increased with gestational age in both the ASA group (r = 0.39) and the control group (r = 0.31). No significant differences in At/Et ratio, PI, or peak systolic velocity were observed between the ASA group and the control group. CONCLUSION: Administration of low-dose ASA during pregnancy did not appear to alter hemodynamics in the fetal ductus arteriosus.

Innate immune cells in reproduction.

Fetomaternal immune tolerance is required to prevent fetal rejection during pregnancy; simultaneously, the maternal immune system must also protect the fetus from harmful endogenous and exogenous antigens, including those associated with viral and bacterial infections. Therefore, a delicate immune balance is critical for the maintenance of a successful pregnancy, while disruption of this balance can induce complications such as implantation failure, miscarriage, preterm birth/labor, preeclampsia and fetal growth restriction. While the adaptive immune system is critical for the development of tolerance, this review summarizes evidence that modulation of the innate immunity is also essential for achieving this delicate balance between tolerance and protection. Canonical cells of the innate immune system, including dendritic cells, macrophages, natural killer cells and invariant natural killer T cells, contribute to the modulation of the immune balance at the fetomaternal interface. The newly identified myeloid-derived suppressor cells and innate lymphoid cells also appear important for successful reproduction. Moreover, it is possible that sterile inflammation facilitates complications of pregnancy via the innate immune system. In this review, the characteristic features and functions of innate immune cells in fetomaternal immunity and their contributions to pregnancy complications related to sterile inflammation are discussed. These insights on innate immune system function in reproduction may provide new perspectives for understanding the mechanisms of fetomaternal tolerance and the etiology of pregnancy complications.

Retrospective cohort study of the risk factors for secondary infertility following hysteroscopic metroplasty of the uterine septum in women with recurrent pregnancy loss.

Purpose: A hysteroscopic metroplasty was performed for women with recurrent pregnancy loss owing to a uterine septum, following which some women became infertile. The aim of this study was to elucidate the risk factors of secondary infertility 1 year after hysteroscopic metroplasty for a uterine septum. Methods: A retrospective, single-center, cohort study included women with a history of at least two miscarriages that had been attributed to a uterine septum who underwent a hysteroscopic metroplasty. The patients' background data were compared between the patients who conceived and those who remained infertile at 1 year postoperatively. The data were analyzed by using the Mann-Whitney U-test and multivariate analyses. Results: The postoperative live birth rate was 83.9% (n = 26), with persistent infertility in five women at 1 year. When comparing the pregnancy group with the infertile group, the women in the postoperative infertility group were significantly older than those in the postoperative pregnancy group. The multivariate analysis showed that age was an independent risk factor for persistent infertility. Conclusion: Age was identified as an independent risk factor for postoperative secondary infertility. Therefore, surgery as early as possible is recommended.

Associations of Nutrients and Dietary Preferences with Recurrent Pregnancy Loss and Infertility.

This review examines associations of nutrients and dietary preferences with recurrent pregnancy loss (RPL), miscarriage, and infertility. Research articles, reviews, and meta-analyses of RPL and infertility that focused on nutrition, meals, and lifestyle were reviewed, and associations of nutrients and dietary preferences with pregnancy are discussed in relation to recent research findings. Studies related to RPL were given the highest priority, followed by those dealing with miscarriage and infertility. Multivitamin supplements-even when lacking folic acid or vitamin A-reduced total fetal loss. High-dose folic acid supplementation before conception reduced the risk of miscarriage and stillbirth. A meta-analysis revealed a strong association of vitamin D deficiency/insufficiency with miscarriage. Another meta-analysis revealed that seafood and dairy products reduced the risk of miscarriage, whereas a caffeine intake of 300 mg/day or more was associated with miscarriage. A balanced diet that included nutrients with antioxidant properties helped prevent miscarriage, whereas a diet that included processed foods and nutrients with proinflammatory effects increased the risk of miscarriage. Associations of nutrients with RPL warrant further research.

Characteristic impairment of progesterone response in cultured cervical fibroblasts obtained from patients with refractory cervical insufficiency.

Preterm birth (PTB) is the leading cause of neonatal mortality, and reducing the PTB rate is one of the most critical issues in perinatal medicine. Cervical insufficiency (CI), a major cause of PTB, is characterised by premature cervical ripening in the second trimester, followed by recurrent pregnancy loss. Although multiple clinical trials have suggested that progesterone inhibits cervical ripening, no studies have focused on progesterone-induced molecular signalling in CI. Here, we established a primary culture system for human uterine cervical fibroblasts using a sample of patients with refractory innate CI who underwent transabdominal cervical cerclage and patients with low Bishop scores who underwent elective caesarean section as controls. RNA sequencing showed that the progesterone response observed in the control group was impaired in the CI group. This was consistent with the finding that progesterone receptor expression was markedly downregulated in CI. Furthermore, the inhibitory effect of progesterone on lipopolysaccharide-induced inflammatory stimuli was also impaired in CI. These results suggest that abnormal cervical ripening in CI is caused by the downregulation of progesterone signalling at the receptor level, and provide a novel insight into the molecular mechanism of PTB.

Successful in Vitro Fertilization Pregnancy and Delivery by an Infertile Woman with Ovotesticular Disorder of Sex Development: A Case Report.

On the basis of postoperative histopathological findings, a 29-year-old nulliparous woman was diagnosed as having ovotesticular disorder of sex development (DSD). She had undergone unilateral gonadectomy at age 6 years and vulvoplasty and vaginoplasty at age 8 years. Her karyotype was 46, XX. She had dyspareunia because of a narrow vagina, but her uterus and left gonad were normal. Spontaneous ovulation was confirmed, but sexual intercourse was impossible because of dyspareunia, despite vaginal self-dilatation with a vaginal dilator. Artificial insemination was initiated; however, five cycles failed to yield a viable pregnancy. We decided to perform in vitro fertilization (IVF), which resulted in conception. During IVF we administered intravenous anesthesia before oocyte collection to reduce her distress due to insufficient lumen expansion after vaginoplasty. The patient delivered a healthy male infant weighing 2,558 g at 37 weeks of gestation via cesarean section, which was performed because of gestational hypertension. This is the eighth report of a viable neonate born from a patient with ovotesticular DSD after gonadectomy and the first such pregnancy achieved by IVF. Therefore, IVF may be an effective option for infertile patients with ovotesticular DSD. Additionally, to prevent dyspareunia, self-management of the plastic vagina is important during the peri- and postoperative periods of early vaginoplasty.

Carcinosarcoma of the uterus, derived from subserous cystic adenomyosis, presenting as an acute abdomen: A case report and review of the literature.

When a woman presents with an acute abdomen with cystic lesions in the abdominal cavity, the differential diagnosis includes torsion or rupture of an ovarian tumor. We report our experience with a 54-year-old nulliparous woman who underwent emergency surgery for a suspected ruptured ovarian tumor. Intraoperative examination revealed disruption of a cystic tumor that had developed externally from the fundus of the uterus. The patient, who was taking aspirin because of a history of medullary infarction, reported lower abdominal discomfort for several days. When she sought care, she was referred to the gynecology department where transvaginal ultrasonography and contrast-enhanced computed tomography showed a poorly toned mass with a maximum diameter of 20 cm posterior to the uterus. She also had a large amount of ascites reaching around the liver and the spleen. She underwent an emergency laparotomy for a presumed diagnosis of acute abdomen caused by a ruptured ovarian tumor with intra-abdominal bleeding. Intraoperative examination revealed normal adnexae bilaterally, but there was a cystic tumor in the pouch of Douglas that was strongly adherent to the surrounding intestines. This mass was connected to the posterior uterus by a stalk and appeared to be continuous with the uterine tissue. The postoperative pathological diagnosis was carcinosarcoma derived from subserous cystic adenomyosis. This is the first case report of carcinosarcoma developing from subserous cystic adenomyosis in the English literature as far as we know.

Superfertility and subfertility in patients with recurrent pregnancy loss: A comparative analysis of clinical characteristics and etiology based on differences in fertile ability.

This study aimed to elucidate the etiologies of and risk factors for recurrent pregnancy loss (RPL) according to fertile ability, focusing on the differences between superfertile and subfertile patients. This retrospective observational study included 828 women with RPL between July 2017 and February 2020. Patients were divided into three groups based on time to pregnancy (TTP): superfertile (SUP) (TTP ≤3 months for all previous pregnancies), subfertile (SUB) (previous TTP ≥12 months and use of assisted reproductive technology [ART]), and Normal (N) (TTP >3 or <12 months without ART). All patients were assessed for uterine anatomy, antiphospholipid antibodies (APAs), thyroid function, and thrombophilia. Of the 828 patients, 22%, 44%, and 34% were assigned to the SUP, SUB, and N groups, respectively. The mean ages were 33.9, 38.2, and 35.9 years in the SUP, SUB, and N groups, respectively, revealing a significant difference (P < 0.001). The anti-CL ß2GPI antibody positivity rate was significantly higher in the SUP group (4.6%) than in the N group (0.8%; P = 0.016). The prevalence of APA positivity was lowest in the N group. Overall, the clinical characteristics and etiologies of RPL associated with superfertility and subfertility were strikingly similar, with comparable positivity rates after adjusting for maternal age. Further investigation including chromosomal analysis of products of conception is needed to elucidate the clinical impact of differences in fertility on patients with RPL.