Frozen versus fresh single blastocyst transfer in ovulatory women: a multicentre, randomised controlled trial

Endometrial Decidualization: The Primary Driver of Pregnancy Health

Interventions to prevent pregnancy complications have been largely unsuccessful. We suggest this is because the foundation for a healthy pregnancy is laid prior to the establishment of the pregnancy at the time of endometrial decidualization. Humans are one of only a few mammalian viviparous species in which decidualization begins during the latter half of each menstrual cycle and is therefore independent of the conceptus. Failure to adequately prepare (decidualize) the endometrium hormonally, biochemically, and immunologically in anticipation of the approaching blastocyst—including the downregulation of genes involved in the pro- inflammatory response and resisting tissue invasion along with the increased expression of genes that promote angiogenesis, foster immune tolerance, and facilitate tissue invasion—leads to abnormal implantation/placentation and ultimately to adverse pregnancy outcome. We hypothesize, therefore, that the primary driver of pregnancy health is the quality of the soil, not the seed.

The Feasibility of All-Blastocyst-Culture and Single Blastocyst Transfer Strategy in Elderly Women: A Retrospective Analysis

Objective

To investigate the feasibility and clinical outcome of the all-blastocyst-culture and single blastocyst transfer strategy in women aged ≥35 years.

Methods

A retrospective analysis of patients aged ≥35 years undergoing IVF/ICSI was performed from January 2017 to April 2019 in the reproductive center of the Second Affiliated Hospital of Wenzhou Medical University. A total of 155 cases treated with ovarian hyperstimulation by prolonged protocol and implemented single (84 cases) or double (71 cases) blastocyst transfer were collected. Then, patients were further divided into <38 yr. group and ≥38 yr. group, and the laboratory and clinical outcomes were compared between the groups.

Results

The double-blastocyst-transfer (DBT) group showed higher clinical pregnancy rate and multiple pregnancy rate and lower neonatal birth weight than those in the single-blastocyst-transfer (SBT) group (P < 0.05). However, there were no statistically significant differences between the groups in the embryo implantation rate, biochemical pregnancy rate, miscarriage rate, preterm delivery rate, and term birth rate. For patients < 38 yr., SBT significantly reduced the multiple pregnancy rate and increased the neonate birth weight without significant reduction in the clinical pregnancy rate. While in the ≥38 yr. group, there are no differences in pregnancy outcomes between SBT and DBT. Logistic regression analysis showed that the number of MII oocytes was positively correlated with the live birth rate (OR = 1.18) and negatively correlated with the miscarriage rate (OR = 0.844), suggesting that elderly patients with relatively normal ovarian reserve would obtain better prospect in pregnancy. The number of fetal heart beat in pregnancy was negatively correlated with the live birth rate (OR = 0.322) and positively correlated with the preterm birth rate (OR = 7.16).

Conclusion

The strategy of all-blastocyst-culture and single blastocyst transfer is feasible, safe, and effective for elderly patients with normal ovarian reserve, which would reduce the multiple pregnancy rate.

After corona: there is life after the pandemic

The current pandemic of Coronavirus Disease 2019 (COVID-19) has focused the attention of medical-care providers away from non-life-threatening diseases, including infertility. Although infertility does not jeopardize the physical survival of infertile couples, it does jeopardize their future quality of life. Human infertility can be caused by a number of factors, some of which are age-dependent, and their effects may become irreversible if appropriate measures are not taken in time to prevent irreversible childlessness. Accordingly, each case of infertility should be evaluated comprehensively to establish its position of priority. Assisted reproductive technology (ART) makes it possible to separate fertilization and pregnancy in time. Whereas pregnant women infected with coronavirus may have an increased risk of adverse neonatal outcomes, gametes do not transmit COVID-19. Thus, performing ovarian stimulation and fertilization without delay, freezing the resulting embryos and delaying embryo transfer until the end of the pandemic appears to be the best strategy at present.

Increased Risk of Pre-eclampsia After Frozen-Thawed Embryo Transfer in Programming Cycles

Objective: This study aims to investigate whether obstetric complications and perinatal outcomes after frozen embryo transfer (FET) in the programming cycles differ from that in the natural cycles.

Methods: We conducted a retrospective cohort study collecting a total of 14,373 singletons born after frozen embryo transfer at the Center for Reproductive Medicine Affiliated to Shandong University from September 2013 to September 2018. The women were divided into two groups according to the regimens for endometrium preparation: either natural cycles (n = 10,211) or programming cycles (n = 4,162). The primary outcomes were the incidence of obstetric complications consisting of pre-eclampsia, gestational diabetes mellitus, placenta previa, placental abruption, and postpartum hemorrhage. The perinatal outcomes included average birthweight, low birthweight (LBW), very LBW, macrosomia, large for gestational age, and small for gestational age. Multivariable logistic regression analysis was performed to adjust for potential confounders.

Results: The incidences of pre-eclampsia (8.6 vs. 3.8%) and postpartum hemorrhage (0.7 vs. 0.2%) in the programming FET cycles were significantly higher than those in the natural FET cycles. The logistic regression analysis showed that, compared to the natural FET cycles, the programming FET cycles were associated with an elevated risk of pre-eclampsia (aOR, 2.55; 95% CI, 2.06–3.16) and postpartum hemorrhage (aOR, 2.94; 95% CI, 1.44–5.99).

Conclusion: The women with singleton delivery after frozen-thawed embryo transfer in the programming cycles had an elevated risk of pre-eclampsia and postpartum hemorrhage, which was speculated to be associated with the absence of the corpus luteum.

Frozen IVF Cycles to Circumvent the Hormonal Storm on Endometrium

Controlled ovarian hyperstimulation (COH) determines an anticipation of endometrial maturation and a premature occurrence of the implantation window, as shown by histological, histochemical, and molecular studies and indirectly by clinical trials. There is growing agreement that in patients hyper-responding to COH and in those undergoing transfer at the blastocyst stage, deferring the transfer in a subsequent frozen cycle could increase pregnancy outcomes. For blastocysts, implantation after a fresh transfer may be limited as the implantation window is already closed while, in hyper-responders to COH, the anticipation magnitude could be more marked thus hampering implantation also for cleavage-stage embryos. Research should focus in depth on pregnancy outcomes and on the most suitable modality to prepare the endometrium for frozen transfers.

Risk factors of gestational diabetes mellitus during assisted reproductive technology procedures

To investigate risk factors of gestational diabetes mellitus (GDM) during assisted reproductive technology (ART) procedures. A total of 1022 patients were included in this retrospective cohort study from January 1, 2014 to August 31, 2017. While patients were divided into two groups: the non- GDM group and the GDM group. There was no significant difference in basal FSH, AFC, infertility years, gestational age, number of fetus, method of fertilization, and reason of infertility between the two groups. However, age, BMI, and fresh cycle were verified to be association with GDM by using logistic regression model. During the process of controlled ovarian hyperstimulation (COH), estradiol (E₂) was significantly lower in the GDM group. The incidence of GDM was highest when E₂ level less than 200 pg/mL of per oocyte. Our study showed maternal fundamental factors had greater impacts on subsequent GDM.

Placental pathology in live births conceived with in vitro fertilization after fresh and frozen embryo transfer

BACKGROUND

The availability and use of frozen embryos after ovarian hyperstimulation for assisted reproduction has increased with improvement in vitrification techniques and the rise of preimplantation genetic testing. However, there are conflicting data regarding whether obstetric outcomes differ between fresh and frozen embryo transfer cycles.

OBJECTIVE

To compare placental pathology from live births arising from fresh and frozen embryo transfer cycles.

MATERIALS AND METHODS

A cohort of 1140 live births with placental pathology arising from autologous in vitro fertilization cycles with fresh or frozen programmed transfer performed at MGH Fertility Center between 2004 and 2017 was retrospectively reviewed. An experienced placental pathologist categorized the reported placental pathology as anatomic, infectious, inflammatory, or vascular/thrombotic. Our primary outcomes were differences in these placental pathologies between the 2 groups. Patient demographic, cycle, and birth outcomes were compared with the use of χ² tests, Student t test, or nonparametric tests, as appropriate. Multivariate logistic regression models were used to compare placental pathology between the fresh and frozen transfer groups.

RESULTS

Of the 1140 cycles included in our analysis, 929 arose from fresh embryo transfers (81.3%) and 211 arose from programmed frozen embryo transfers (18.5%). For both transfer types, the average age of the women at time of treatment was 35 years; mean body mass indices were within the normal range (23.6 kg/m² for fresh transfers and 23.2 kg/m² for frozen transfers, P = .26), and mean day 3 follicle-stimulating hormone values were 7.1 and 7.0 IU/L (P = .44), respectively. Deliveries occurred on average at 37.5 and 38.0 weeks' gestational age (P = .04) in the fresh versus frozen transfer group, with similar rates of obstetric complications. However, frozen transfers were more likely to be associated with marginal cord insertion (adjusted odds ratio, 1.87; confidence interval, 1.21, 2.91; P = .01), accessory lobe formation (adjusted odds ratio, 2.96; confidence interval, 1.12, 7.79; P = 0.03), subchorionic thrombi (adjusted odds ratio, 3.72; confidence interval, 1.80, 7.71; P < .001), and fetal vascular malperfusion characteristics with cord anomalies (adjusted odds ratio, 2.34; confidence interval, 1.22, 4.46; P = .01). These trends persisted when we analyzed day 5 transfers alone, and single frozen embryo transfers remained associated with increased rates of subchorionic thrombi compared to single fresh embryo transfers.

CONCLUSION

Pregnancies arising from frozen embryo transfers demonstrated more anatomic and vascular placental pathology than those from fresh transfers in our cohort of patients, despite similar maternal outcomes. More research is needed to explore how these differences in pathology may influence obstetric and perinatal outcomes.

Major Factors Affecting the Live Birth Rate After Frozen Embryo Transfer Among Young Women

In recent years, the freeze-all strategy has been widely adopted and applied. However, with the exception of age, the factors that affect the outcomes of frozen embryo transfer are still unclear. Therefore, the identification and mitigation of factors that influence the live birth rate after frozen embryo transfer is a good way to increase the "take-home-baby" rate of frozen embryo transfer. The objective of this study was to identify factors affecting the live birth rate after cleavage-stage frozen embryo transfer in young ovulatory women. This was a secondary analysis from a previously published multicenter randomized controlled trial (ChiCTR-IOR-14005406) that was originally designed to compare the live birth rate and perinatal complications after fresh embryo transfer to those after frozen embryo transfer among ovulatory women. This study was carried out using a portion of the data from the original randomized controlled trial, which included 917 young women who underwent cleavage-stage frozen embryo transfer. The 16 clinical candidate variables potentially affecting the live birth rate after frozen embryo transfer were analyzed. Univariable analysis and multivariable analysis were performed to assess the relationship between predictive factors and outcomes, with the aim of identifying independent predictors of live birth after frozen embryo transfer. In this study, the live birth rate was 53.0% (486/917). Three independent predictors were ultimately identified as the main factors affecting the live birth rate of ovulatory young women. Infertility duration [odds ratio (OR): 0.933, 95% confidence interval (CI): 0.876-0.995, p = 0.033], endometrial thickness before frozen embryo transfer (OR: 3.375, 95% CI: 1.556-7.321 p = 0.002), and the number of embryos transferred (OR: 2.653, 95% CI:1.226-5,743, p = 0.013) were the major factors contributing to the live birth rate after cleavage-stage frozen embryo transfer among young women. The cut-off point for infertility duration was 4.5 years, and the cut-off point for endometrial thickness was 0.89 cm. Infertility duration, endometrial thickness and number of embryos transferred might affect the live birth rate after frozen embryo transfer among young women. This result could help inform clinical decisions and counseling to increase the live birth rate after frozen embryo transfer among young women.

Pregnancy and perinatal outcomes in pregnancies resulting from time interval between a freeze-all cycle and a subsequent frozen-thawed single blastocyst transfer

Background

Adverse obstetric outcomes are correlated with altered circulating hormone levels at the time implantation by the trophectoderm. What’ more, embryo freezing process may also have adverse effect on perinatal outcomes. This study aims to evaluate whether increasing interval time between a freeze-all cycle and a subsequent frozen-thawed single blastocyst transfer could have any effect on pregnancy and perinatal outcomes.

Methods

This was a retrospective cohort study included the first single blastocyst transfer in artificially cycles of all patients who underwent a freeze-all cycle between January 1^st, 2016 and September 30^th, 2018. All patients were divided into two groups according to the time interval between oocyte retrieval and the day of first frozen-thawed embryo transferred (FET): Group 1 (immediate FET cycles) and Group 2 (delayed FET cycles).

Results

No significant differences were reported between the two groups regarding the rates of clinical pregnancy, live birth, biochemical pregnancy and pregnancy loss even after adjusting for measured confounding. When accounting for perinatal outcomes, gestational age, birth weight, delivery mode, fetus gender, preterm birth, gestational hypertension, GDM, placenta previa, fetal malformation and low birthweight also did not vary significantly between the two groups. Only the incidence of macrosomia was more frequently in the Group 2 compared with the Group 1 (AOR 3.886, 95%CI 1.153–13.103, P = 0.029) after adjusting with a multiple logistic regression model.

Conclusions

We found delayed FET cycles for blastocyst transfer following freeze-all cycles may not improve the pregnancy outcomes. On the contrary, postponement of FET cycles may increase the risk of macrosomia. Therefore, FET cycles for blastocyst transfer should be done immediately to avoid adverse effects of delayed time on perinatal outcomes.

Cumulative live birth rates according to the number of oocytes retrieved following the "freeze-all" strategy

BACKGROUND

In recent years, some studies have shown that there is a positive association between the number of oocytes retrieved and the cumulative live birth rate (CLBR) after fresh and frozen cycles of one oocyte retrieval. However, almost no studies have examined the association between the number of oocytes retrieved and the CLBR when using the "freeze-all" strategy. We performed this study to investigate the effects of an extreme oocyte yield during the first "freeze-all" cycle on the cumulative live birth rate among patients younger than 35 years old.

METHODS

This was a retrospective cohort study performed in a university-affiliated reproductive medicine centre. Data obtained from 3276 women aged younger than 35 years who underwent their first "freeze-all" cycle (IVF/ICSI) were collected between January 2009 and December 2016. In all, 5025 frozen cycles took place during the follow-up period from January 2009 to December 2018. Patients were divided into five groups according to oocytes retrieved (group 1: 4-10 oocytes; group 2: 11-20 oocytes; group 3: 21-30 oocytes; group 4: 31-40 oocytes; group 5: > 40 oocytes). The primary outcome was the cumulative live birth rate.

RESULTS

Unadjusted results showed that the cumulative live birth rate significantly increased as the number of oocytes retrieved increased and reached up to 93.82% in cases with yields of 21-30 oocytes (P < 0.05), after which it did not have a significant increase (P > 0.05). After adjusting for confounders, our results showed that the number of oocytes retrieved is an independent positive predictor of cumulative live birth rate when using a "freeze-all" strategy. (P < 0.001). In addition, the fertilization rate and the gonadotropin dose also influenced the cumulative live birth rate (P<0.05).

CONCLUSIONS

Among women younger than 35 years old who underwent the "freeze-all" strategy, the number of oocytes retrieved positively correlated with the cumulative live birth rate. Taking both efficacy and safety into account, ovarian stimulation should be rational, and the upper limit of the oocyte yield should be no more than 30.

Morula transfer achieves better clinical outcomes than post-thawed cleavage embryos after overnight culture in frozen embryo transfer (FET) cycles

PURPOSE

This study aimed to investigate the clinical outcomes of morula stage transfer derived from post-thawed cleavage embryos undergoing overnight culture in frozen embryo transfer (FET) cycles.

METHODS

We performed a retrospective study that included 392 FET cycles with 784 thawed embryos undergoing overnight culture between January 2014 and December 2018. Embryos were divided into three groups in terms of their status: 8-16 cells without morula (group I), one morula (group II), and two morulae (group III). The clinical outcomes of these cycles were then compared between the three groups. Logistic regression analysis was performed to control for confounders.

RESULTS

Group III was associated with a significantly higher clinical pregnancy rate (odds ratio [OR] 2.35; 95% confidence interval [CI] 1.29-4.27; P = 0.005), implantation rate (OR 3.00; CI 1.75-5.16; P < 0.001), multiple pregnancy rate (OR 4.91; CI 2.11-11.40; P < 0.001), and live birth rate (OR 1.96; CI 1.10-3.49; P = 0.022) than group I. Group II had a higher live birth rate than group I after adjustment (OR 1.70; CI 1.04-2.79; P = 0.035). There was no difference in the rate of premature delivery when compared across the three groups after adjustment.

CONCLUSION

The transfer of morula stage embryos following the overnight culture of post-thawed cleavage embryos led to an improvement in the clinical outcomes of FET cycles. It is important to reduce the number of morula embryos transferred in order to achieve a singleton pregnancy.

Association between the number of top-quality blastocysts and live births after single blastocyst transfer in the first fresh or vitrified-warmed IVF/ICSI cycle

RESEARCH QUESTION

Is there an association between the total number of top-quality blastocysts (TQB) developed in the first IVF/intracytoplasmic sperm injection cycle (ICSI) and live births after a single blastocyst transfer (SBT)?

DESIGN

Pregnancy outcomes from 1336 infertile women who had undergone their first IVF/ICSI treatment and accepted a first-time embryo transfer with a single fresh or vitrified-warmed blastocyst between January 2016 and August 2018 were assessed retrospectively. The restricted cubic splines method was used to evaluate the association between the number of TQB, and ongoing pregnancies and live births.

RESULTS

A significant non-linear functional form was found between the number of TQB and the ongoing pregnancies and live births (P < 0.05). The odds of an ongoing pregnancy or live birth were similar, at about 11% or higher for each additional TQB up to five TQB (odds ratio [OR] 1.11; 95% confidence interval [CI] 1.01-1.21). After this, pregnancy outcomes nearly plateaued, indicating that the number of TQB was not related to pregnancy when it was greater than five.

CONCLUSIONS

The quantity of TQB available for transfer or cryopreservation can provide important predictors for pregnancy and live birth after the first embryo transfer cycle with a single blastocyst. This valuable information may assist with the future application of SBT.

Cell number considerations for blastocyst transfer in younger patients

OBJECTIVE

To investigate the role of the cell number at day 3 in blastocyst selection.

DESIGN

Observational, retrospective, single-center clinical study.

PATIENT(S)

In part 1, 1211 single vitrified-warmed blastocyst transfer (SVBT) cycles were identified and reviewed. All the cycles were conventional in vitro fertilization (IVF) cycles and the first embryo transfer cycles. Most of patients had a risk of ovarian hyperstimulation syndrome and were young. In part 2, 864 IVF-derived blastocysts from 292 infertile couples underwent trophectoderm (TE) biopsy for preimplantation genetic testing for aneuploidies (PGT-A).

INTERVENTION(S)

No patient intervention.

MAIN OUTCOME MEASURE(S)

The first part was an analysis of the correlation between the cell number at day 3 and live birth rate (LBR) after SVBT, and the second part was an analysis of the correlation between the cell number at day 3 and euploid rate (ER) of blastocysts.

RESULT(S)

In part 1, after correcting for the effects of other confounders, the cell number at day 3 had no significant effect on the LBR (OR 1.001, 95% CI 0.938-1.068). In part 2, after correcting for the effects of other confounders, the cell number at day 3 had no significant effect on the ER (OR 0.960, 95% CI 0.866-1.063).

CONCLUSION(S)

When the vitrified-warmed blastocysts obtained by conventional IVF are transferred into young patients, the cell number at day 3 is not a strong predictor of the LBR. In addition, the cell number at day 3 is not a strong predictor of ER of IVF-derived blastocysts too.

Higher implantation and live birth rates with laser zona pellucida breaching than thinning in single frozen-thawed blastocyst transfer

While zona pellucida (ZP) breaching of day-3 frozen blastocysts embryos can increase the blastocyst hatching rate, compared with ZP thinning, the pregnancy and implantation rates are similar. The aim of this study was to compare pregnancy outcomes and the risks associated with frozen-thawed blastocysts between laser ZP breaching and laser ZP thinning. For the thinning group, ZP of thawed blastocyst was thinned to a length of 30-40 μm using laser between January 2013 and October 2015. On the other hand, for the breaching group, thawed blastocysts were breached with a 60-80 μm hole in the ZP using laser between November 2015 and April 2018. The implantation rate of ZP breaching (72.7%) was higher than that of ZP thinning (61.8%). In single frozen blastocyst transfer, the implantation rate, clinical pregnancy rate, and live birth rate of ZP breaching (73.9%, 73.9%, 61.8%, respectively) were significantly higher than those of ZP thinning (60.9%, 60.9%, 46.7%, respectively). The abortion rate, preterm birth rate, congenital malformation, birth defects, and birth weight did not significantly differ between the two groups. In conclusion, laser assisted hatching during single frozen blastocyst transfer using ZP breaching exhibit higher implantation, pregnancy, and live birth rates compared with ZP thinning. No significant differences were observed between the two assisted hatching methods in terms of adverse effects on pregnancy and newborns.

Late Follicular Phase Ovarian Stimulation Without Exogenous Pituitary Modulators

Introduction: A gonadotropin-releasing hormone antagonist is the most common modulator used to prevent the premature luteinizing hormone (LH) surge when ovarian stimulation was initiated in the late follicular phase. We aimed in this study to evaluate the feasibility of performing ovarian stimulation in the late follicular phase without the use of exogenous pituitary modulators. Methods: Data were retrospectively collected from 404 normo-ovulatory patients who underwent their first in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment in our department. One hundred sixteen subjects in the study group received ovarian stimulation when a dominant follicular diameter of ≥ 10 mm was confirmed by transvaginal ultrasonography after menstrual cycle day 6, which entailed a daily injection of gonadotropin until the trigger day, while 288 subjects in the control group received ovarian stimulation in the early follicular phase under a progesterone protocol. The primary outcome was the number of mature oocytes. Results: There was no statistical difference in the number of mature oocytes between the two groups (9.67 ± 5.33 in the study group vs. 9.38 ± 5.15 in the control group, P = 0.693). No secondary LH surges in the study group and no premature LH surges in the control group were found during ovarian stimulation. The good-quality embryo rate per oocyte retrieved showed no significant difference between the two groups (35.22 vs. 35.91%, P = 0.665). The clinical pregnancy rate per transfer was 54.55% in the study group and 56.48% in the control group (P = 0.718), and the implantation rate was similar between the two groups (36.94 vs. 37.77%, P = 0.829). Conclusions: Our study revealed that late follicular phase ovarian stimulation could be performed without an exogenous pituitary modulator.

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 Embryo Cryopreservation Causing Macrosomia-and What Else?

The number of embryos transferred during an IVF cycle is directly related to the high incidence of multiple births, which is the culprit of perinatal morbidity. Therefore, single fresh embryo transfer (ET) strategy, or freeze-all, followed by a single frozen-thawed embryo transfer (FET) cycle, may dramatically reduce the rate of multiple births, without compromising the cumulative live birth rates (LBRs). A literature review was conducted for all available evidences assessing obstetrics and perinatal outcomes associated with FET compared to fresh ET and natural conception. While studies comparing fresh and FET cycles in normal responders have yielded conflicting results for pregnancy rate, FET was associated with lower risk of prematurity and low birth weight and increased risk of large for gestational age (LGA) and/or macrosomic in singletons, when compared with fresh ET. Macrosomic/LGA births have a higher risk of fetal hypoxia, stillbirth, shoulder dystocia, perineal lacerations, cesarean section, postpartum hemorrhage and neonatal metabolic disturbances at birth. Nonetheless, it seems that other than higher risk of fetal macrosomia, there are additional obstetric complications associated with FET. The relative risk of hypertensive disorders in pregnancy, as well as perinatal mortality were also demonstrated to be increased in FET compared with singletons from fresh ET and natural conception. Therefore, when considering elective freeze-all policy, in addition to LBR and the risk of ovarian hyperstimulation syndrome, physicians should consider the aforementioned increased FET cycles' pregnancy complications, including LGA/ macrosomia, hypertensive disorders of pregnancy, as well as perinatal mortality.

Effect of the Interaction Between Pre-pregnancy Body Mass Index and Fresh/Frozen Embryo Transfer on Perinatal Outcomes of Assisted Reproductive Technology-Conceived Singletons: A Retrospective Cohort Study

Objective: To demonstrate the association between pre-pregnancy maternal overweight, obesity, and perinatal outcomes of singletons conceived by assisted reproductive technology (ART). Design: Retrospective cohort study from 2006 to 2015 data from a single ART center. Setting: Assisted Reproduction Center, Northwest Women's and Children's Hospital, Xi'an, Northwestern China. Patients: We included 7,818 women undergoing ART and their singleton infants. Interventions: None. Main Outcome Measure: The primary outcome measures were preterm birth (PTB), macrosomia, low birth weight, small for gestational age, and large for gestational age (LGA). Results: We experienced an increase in the risk of PTB, macrosomia, and LGA in overweight and obese groups compared with that in normal-weight groups [PTB: overweight vs. normal weight: odds ratio [OR] = 1.44, 95% CI: 1.18-1.75; obesity vs. normal weight: OR = 1.53, 95% CI: 1.04-2.25; macrosomia: overweight vs. normal weight: OR = 1.78, 95% CI: 1.48-2.14; obesity vs. normal weight: OR = 2.16, 95% CI: 1.52-3.06; LGA: overweight vs. normal weight: OR = 1.63, 95% CI: 1.39-1.90; obesity vs. normal weight: OR = 2.11, 95% CI: 1.57-2.83]. We observed a significant interaction between maternal BMI and fresh/frozen embryo transfer on PTB and LGA (P = 0.030; P = 0.030). Fresh embryo transfer significantly increased the effect of maternal BMI on LGA (fresh: OR = 1.14, 95% CI: 1.10-1.18; frozen: OR = 1.09, 95% CI: 1.04-1.13), and frozen embryo transfer increased the effect of maternal BMI on PTB (fresh: OR = 1.03, 95% CI: 0.99-1.08; frozen: OR = 1.09, 95% CI: 1.04-1.15). Conclusions: Pre-pregnancy maternal overweight and obesity were associated with higher risks of PTB, macrosomia, and LGA in ART-conceived singletons. These associations were affected by the timing of embryo transfer (fresh/frozen embryo transfer). Therefore, we recommend women before ART to maintain a normal BMI for the prevention of adverse perinatal outcomes.

Hormone Replacement Versus Natural Cycle Protocols of Endometrial Preparation for Frozen Embryo Transfer

RESEARCH QUESTION

Endometrial preparation is one of the most important steps for ensuring frozen embryo transfer success. However, there is no clear evidence that identifies an optimal endometrial preparation protocol for frozen embryo transfer. In addition, in studies that assessed which were the optimal endometrial preparation protocols, few analyzed the stage and the number of embryos. This study compared the pregnancy outcomes and perinatal obstetric complications of patients who were transferred two cleavage-stage (day 2 or day 3) frozen embryos with the natural cycle and those with the hormone replacement therapy cycle.

DESIGN

This study was a secondary analysis of data from a multicentre randomized controlled trial designed to compare the pregnancy and perinatal outcomes after frozen versus fresh embryo transfer. In this study, a total of 908 patients who were transferred two cleavage-stage (day 2 or day 3) embryos in the original trial were analyzed. Pregnancy outcomes and perinatal obstetric complications after the natural cycle and the hormone replacement therapy cycle were compared.

RESULT

We found the endometrium in the natural group was significantly thicker than the hormone replacement therapy cycle group (p<0.01). The implantation rate (42.6% vs 37.3% p=0.049) showed a significant difference between the natural cycle group and the hormone replacement therapy cycle group. Compared to the natural cycle group, the hormone replacement therapy cycle group was associated with an increased risk of caesarean section (72.3% vs 84.5, p=0.009).

CONCLUSION

The natural cycle protocol yielded thicker endometria, a higher implantation rate and a lower risk of caesarean section than the hormone replacement therapy protocol in the transfer of two cleavage-stage frozen embryos. The natural cycle protocol was the better endometrial preparation protocol for frozen embryo transfer.

Luteal phase after conventional stimulation in the same ovarian cycle might improve the management of poor responder patients fulfilling the Bologna criteria: a case series

OBJECTIVE

To assess the clinical contribution of luteal-phase stimulation (LPS) to follicular-phase stimulation (FPS) in a single ovarian cycle (DuoStim) for poor responder patients fulfilling the Bologna criteria.

DESIGN

Observational study (years 2015-2017) including women satisfying ≥2 of the following characteristics: maternal age ≥40 years and/or ≤3 oocytes retrieved after previous conventional stimulation and/or reduced ovarian reserve (i.e., antral follicle count <7 follicles or antimüllerian hormone <1.1 ng/mL). The LPS was started regardless of the outcome of the FPS.

SETTING

Private in vitro fertilization center.

PATIENT(S)

A total of 100 of 297 patients fulfilling the Bologna criteria chose to undergo DuoStim.

INTERVENTION(S)

The FPS and LPS with the same antagonist protocol and agonist trigger, intracytoplasmic sperm injection with ejaculated sperm, preimplantation genetic testing for aneuploidies, and vitrified-warmed euploid single blastocyst transfer.

MAIN OUTCOME MEASURE(S)

The contribution of LPS to the cumulative live birth rate (CLBR) per intention-to-treat (ITT).

RESULT(S)

Patients (100) underwent FPS (maternal age, 42.1 ± 1.4 y; previous in vitro fertilization cycles with ≤3 collected oocytes, 0.7 ± 0.9; antral follicle count, 3.8 ± 1.2 follicles; and antimüllerian hormone, 0.56 ± 0.3 ng/mL). Ninety-one patients completed DuoStim. All patients were included in the analysis. More oocytes were obtained after LPS with similar developmental and chromosomal competence as paired FPS-derived ones. The CLBR per ITT increased from 7% after FPS to 15% after DuoStim. Conversely, the CLBR per ITT among the 197 patients that chose a conventional controlled ovarian stimulation strategy was 8%, as only 17 patients who were not pregnant returned for a second stimulation after the first attempt (drop-out rate, 81%).

CONCLUSION(S)

The LPS-derived oocytes increased the CLBR per ITT in a single ovarian cycle in patients fulfilling the Bologna criteria. The DuoStim strategy is promising to manage this thorny population of patients, especially to avoid discontinuation after a first failed attempt.

Preparation of the endometrium and timing of blastocyst transfer in modified natural cycle frozen-thawed embryo transfers (mNC-FET): a study protocol for a randomised controlled multicentre trial

INTRODUCTION

Despite the high number of frozen embryo transfer (FET) cycles being conducted (190 000 cycles/year) in Europe, the timing of blastocyst transfer and the use of luteal phase progesterone support in modified natural cycle FET (mNC-FET) in assisted reproductive technologies are controversial. In mNC-FET, the timing of blastocyst warming and transfer is determined according to the time of implantation in a natural cycle, aiming to reach blastocyst endometrial synchronicity. However, the optimal day of blastocyst transfer following ovulation trigger is not determined. In addition, the value of luteal phase support to maintain the endometrium remains uncertain. Thus, there is a need to identify the optimal timing of blastocyst warming and transfer and the effect of luteal phase support in a randomised controlled trial design. The aim of this randomised controlled trial is to investigate if progesterone supplementation from the early luteal phase until gestational age 8 weeks is superior to no progesterone supplementation and to assess if blastocyst warming and transfer 6 days after ovulation trigger is superior to 7 days after ovulation trigger in mNC-FET with live birth rates as the primary outcome.

METHODS AND ANALYSIS

Multicentre, randomised, controlled, single-blinded trial including 604 normo-ovulatory women aged 18-41 years undergoing mNC-FET with a high-quality blastocyst originating from their first to third in vitro fertilisation/intracytoplasmic sperm injection cycle. Participants are randomised (1:1:1:1) to either luteal phase progesterone or no luteal phase progesterone and to blastocyst warming and transfer on day 6 or 7 after human chorionic gonadotropin trigger. Only single blastocyst transfers will be performed.

ETHICS AND DISSEMINATION

The study is approved by the Danish Committee on Health Research Ethics (H-18025839), the Danish Medicines Agency (2018061319) and the Danish Data Protection Agency (VD-2018-381). The results of the study will be publicly disseminated.

TRIAL REGISTRATION NUMBER

The study is registered in EudraCT (2018-002207-34) and on ClinicalTrials.gov (NCT03795220); Pre-results.

Timing of frozen-thawed embryo transfer after controlled ovarian stimulation in a non-elective freeze-all policy

Background

Non-elective freeze-all policy has been increasingly utilized in assisted reproductive treatment, but the optimal timing of frozen-thawed embryo transfer (FET) after controlled ovarian stimulation (COS) remains to be investigated.

Methods

This retrospective cohort study included 2,998 patients who underwent their first FETs after the first COS cycles using the non-elective freeze-all strategy from Jan 2013 to Dec 2016 at a tertiary-care academic medical center. Patients were divided into the "immediate" group in which FET took place within the first menstrual cycle after oocyte retrieval, and the "delayed" group where FET started after one or more menstrual cycles following COS.

Results

The mean interval between oocyte retrieval and FET was 33.3±5.8 days in the immediate group (n=280; 9.3%) and 91.3±19.4 days in the delayed group (n=2,718; 90.7%). Cycles with delayed FET had a significantly lower live birth rate than those with immediate FET before [1,246/2,718 (45.8%) vs. 156/280 (55.7%); P=0.002] and after propensity score matching (PSM) [123/280 (43.9%) vs. 156/280 (55.7%); P=0.005]. When controlling for a number of confounding factors by multivariable logistic regression analysis, the risk remained significant with the adjusted odds ratio (aOR) [95% confidence interval (CI)] of 0.69 (0.53-0.90) and 0.60 (0.42-0.85) before and after matching, respectively.

Conclusions

Performing FET immediately within the first menstrual cycle following COS was associated with a higher chance to achieve live birth compared with delaying FET to subsequent cycles in a non-elective freeze-all policy. However, further randomized controlled trials are still needed to confirm this conclusion.

Live birth rates and perinatal outcomes when all embryos are frozen compared with conventional fresh and frozen embryo transfer: a cohort study of 337,148 in vitro fertilisation cycles

BACKGROUND

It is not known whether segmentation of an in vitro fertilisation (IVF) cycle, with freezing of all embryos prior to transfer, increases the chance of a live birth after all embryos are transferred.

METHODS

In a prospective study of UK Human Fertilisation and Embryology Authority data, we investigated the impact of segmentation, compared with initial fresh embryo followed by frozen embryo transfers, on live birth rate and perinatal outcomes. We used generalised linear models to assess the effect of segmentation in the whole cohort, with additional analyses within women who had experienced both segmentation and non-segmentation. We compared rates of live birth, low birthweight (LBW < 2.5 kg), preterm birth (< 37 weeks), macrosomia (> 4 kg), small for gestational age (SGA < 10th centile), and large for gestational age (LGA > 90th centile) for a given ovarian stimulation cycle accounting for all embryo transfers.

RESULTS

We assessed 202,968 women undergoing 337,148 ovarian stimulation cycles and 399,896 embryo transfer procedures. Live birth rates were similar in unadjusted analyses for segmented and non-segmented cycles (rate ratio 1.05, 95% CI 1.02-1.08) but lower in segmented cycles when adjusted for age, cycle number, cause of infertility, and ovarian response (rate ratio 0.80, 95% CI 0.78-0.83). Segmented cycles were associated with increased risk of macrosomia (adjusted risk ratio 1.72, 95% CI 1.55-1.92) and LGA (1.51, 1.38-1.66) but lower risk of LBW (0.71, 0.65-0.78) and SGA (0.64, 0.56-0.72). With adjustment for blastocyst/cleavage-stage embryo transfer in those with data on this (329,621 cycles), results were not notably changed. Similar results were observed comparing segmented to non-segmented within 3261 women who had both and when analyses were repeated excluding multiple embryo cycles and multiple pregnancies. When analyses were restricted to women with a single embryo transfer, the transfer of a frozen-thawed embryo in a segmented cycles was no longer associated with a lower risk of LBW (0.97, 0.71-1.33) or SGA (0.84, 0.61-1.15), but the risk of macrosomia (1.74, 1.39-2.20) and LGA (1.49, 1.20-1.86) persisted. When the analyses for perinatal outcomes were further restricted to solely frozen embryo transfers, there was no strong statistical evidence for associations.

CONCLUSIONS

Widespread application of segmentation and freezing of all embryos to unselected patient populations may be associated with lower cumulative live birth rates and should be restricted to those with a clinical indication.

Large-for-gestational age is male-gender dependent in artificial frozen embryo transfers cycles: a cohort study of 1295 singleton live births

RESEARCH QUESTION

What is the effect of frozen embryo transfer (FET) on infant birth weight outcomes and which variables predic large-for-gestational age (LGA) infants.

DESIGN

In a large cohort study, the birth weight of 1295 singleton live births from blastocyst freeze-all-IVF treatments carried out between February 2015 and February 2017 at a single IVF centre were analysed. All embryo transfers were vitrified-warmed blastocyst transfers in artificial FET cycles, with patients having one (n = 864) or two (n = 431) blastocysts transferred. All live births were from ultrasound confirmed single fetal heart pregnancies.

RESULTS

The mean gestational age at delivery was 38.2 (±1.7) weeks, with a 1.11 : 1 female to male ratio for infants delivered. The small and large-for-gestational age rates were 5.02 and 13.28%, with 81.7% of infants appropriate for gestational age. In a multiple logistic regression analysis, the independent variables selected in the model to predict having an LGA infant were maternal parity, infant gender and maternal body mass index (BMI). The risk for LGA at term was significantly higher for male infants when adjusting for maternal parity and BMI (2.8 OR 1.805 to 4.450; P < 0.001).

CONCLUSION

The present study showed that fetal growth of artificial cycle FET pregnancies resulted in an 13.28% LGA infant rate that was mostly male gender dependent.

The impact of peak estradiol during controlled ovarian stimulation on the cumulative live birth rate of IVF/ICSI in non-PCOS patients

OBJECTIVE

The study aimed to investigate the impact of the peak E2 level during controlled ovarian hyperstimulation (COS) on the cumulative live birth rate (cLBR) in non-PCOS women with normal ovarian reserve.

MATERIALS AND METHODS

Women between 20 and 39 years were included. Donor cycles and patients who never experienced embryo transfer were excluded. Multivariable regression and smooth curve fitting were applied for statistical analysis.

RESULTS

A total of 1141 patients were included. The mean age, basal AFC, peak E2 level, and number of retrieved oocyte were 30.0 ± 3.7 years old, 16.8 ± 6.7, 3911.0 ± 1302.9 pg/ml, and 13.6 ± 5.5, respectively. In the overall population of the cohort, cLBR, miscarriage rate, and preterm birth rate were 66.9%, 7.4%, and 13.7%, respectively. The results of multivariable regression analysis failed to show the impact of peak E2 on the cLBR [OR (95%CI) 0.995 (0.982, 1.009), P = 0.486]. However, the result of smooth curve fitting indicated that when the peak E2 was lower than 2185 pg/ml, the cLBR increased about 12% with 100 pg/ml increasing of the peak E2. When the peak E2 was higher than 6136 pg/ml, the cLBR decreased about 10% with 100 pg/ml increasing of the peak E2.

CONCLUSION

We concluded that the peak E2 level on hCG trigger day is associated with the cLBR in a segmental pattern. There should be an appropriate range of the peak E2 level during COS to achieve a relative best cLBR in non-PCOS patients using stimulating protocol mainly based on GnRH agonist; however, the cutoff value must vary in different centers.

Methylation-reprogrammed AGTR1 results in increased vasoconstriction by angiotensin II in human umbilical cord vessel following in vitro fertilization-embryo transfer

AIMS

Assisted reproductive technologies (ART) have been widely used to treat infertility, which may impact on fetuses and offspring. This study investigated the effects of in vitro fertilization-embryo transfer (IVF-ET) on angiotensin II (AII)-mediated vasoconstrictions in umbilical cord vein, and explored possible reprogrammed methylation mechanism.

MATERIALS AND METHODS

Human umbilical cords were randomly divided into ordinary pregnancy and IVF-ET pregnancy. Vascular studies with AII as well as its specific receptor antagonists losartan and PD123,319 were conducted. Real-time quantitative PCR, Western blotting, and methylation analysis by bisulfite sequencing were performed with the cord vessel samples.

KEY FINDINGS

In IVF-ET group, the maximal response to AII in umbilical vessels was significantly greater than that in the ordinary pregnancy. Using losartan and PD123,319, angiotensin receptor subtype 1 (AT1R) was found mainly responsible for the enhanced contraction in the umbilical vein of IVF-ET pregnancy. Decreased mRNA expression of DNMT3A was found in umbilical vein of IVF-ET group. Hypomethylation of the AGTR1 gene (gene encoding AT1R) in the umbilical veins of the IVF group was found. The data suggested that the IVF-ET treatments altered AII-mediated vasoconstrictions in umbilical veins, which could be partially attributed to the increased expression of AT1R.

SIGNIFICANCE

The hypo-methylation of the AGTR1 gene caused by IVF-ET might play important roles in altered vasoconstrictions, impacting on cardiovascular systems in the long run.

The greater incidence of small-for-gestational-age newborns after gonadotropin-stimulated in vitro fertilization with a supraphysiological estradiol level on ovulation trigger day

Introduction

Reproductive scientists have postulated various risk factors for lower birthweight following conventional gonadotropin‐stimulated in vitro fertilization compared with spontaneously conceived children: parental factors (age, health, duration of subfertility and smoking habits); ovarian stimulation; laboratory procedures; the number of oocytes retrieved and the number of embryos transferred. Our aim was to investigate the impact of gonadotropin stimulation and serum estradiol level on the risk of a newborn being small‐for‐gestational‐age.

Material and methods

We conducted a cohort study (2010‐2016) of singletons (n = 155) born either after conventional gonadotropin‐stimulated in vitro fertilization (using ≥150 IU/d human gonadotropin for stimulation) or after natural cycle in vitro fertilization without any stimulation. We analyzed perinatal outcomes using birthweight percentiles, adjusted for gestational age and sex.

Results

The proportion of small‐for‐gestational‐age was 11.8% following conventional gonadotropin‐stimulated in vitro fertilization and 2.9% after natural cycle in vitro fertilization (P = 0.058). The odds of small‐for‐gestational‐age were significantly higher with supraphysiological estradiol levels in maternal serum on ovulation trigger day (unadjusted odds ratio 4.58; 95% confidence interval 1.35‐15.55; P = 0.015). It remained significant after adjusting for maternal height, age and body mass index (adjusted odds ratio 3.83; 95% confidence interval 1.06‐13.82; P = 0.041).

Conclusions

We found an associated risk of children being born small‐for‐gestational‐age after conventional gonadotropin‐stimulated in vitro fertilization compared with natural cycle in vitro fertilization. This higher risk is significantly associated with supraphysiological estradiol levels. We propose a reduction in the dosage of gonadotropin to minimize the risk of small‐for‐gestational‐age and future health consequences.

Worldwide decline of IVF birth rates and its probable causes

With steadily improving pregnancy and live birth rates, IVF over approximately the first two and a half decades evolved into a highly successful treatment for female and male infertility, reaching peak live birth rates by 2001-2002. Plateauing rates, thereafter, actually started declining in most regions of the world. We here report worldwide IVF live birth rates between 2004 and 2016, defined as live births per fresh IVF/ICSI cycle started, and how the introduction of certain practice add-ons in timing was associated with changes in these live birth rates. We also attempted to define how rapid worldwide 'industrialization' (transition from a private practice model to an investor-driven industry) and 'commoditization' in IVF practice (primary competitive emphasis on revenue rather than IVF outcomes) affected IVF outcomes. The data presented here are based on published regional registry data from governments and/or specialty societies, covering the USA, Canada, the UK, Australia/New Zealand (combined), Latin America (as a block) and Japan. Changes in live birth rates were associated with introduction of new IVF practices, including mild stimulation, elective single embryo transfer (eSET), PGS (now renamed preimplantation genetic testing for aneuploidy), all-freeze cycles and embryo banking. Profound negative associations were observed with mild stimulation, extended embryo culture to blastocyst and eSET in Japan, Australia/New Zealand and Canada but to milder degrees also elsewhere. Effects of 'industrialization' suggested rising utilization of add-ons ('commoditization'), increased IVF costs, reduced live birth rates and poorer patient satisfaction. Over the past decade and a half, IVF, therefore, has increasingly disappointed outcome expectations. Remarkably, neither the profession nor the public have paid attention to this development which, therefore, also has gone unexplained. It now urgently calls for evidence-based explanations.