Does dual oocyte retrieval with continuous FSH administration increase the number of mature oocytes in low responders? An open-label randomized controlled trial

STUDY QUESTION

Is there an increase in the total number of metaphase II (MII) oocytes between a conventional ovarian stimulation (OS) and a double uninterrupted stimulation?

SUMMARY ANSWER

There is no increase in the total number of MII oocytes when comparing one conventional OS to a continuous stimulation with double oocyte aspiration.

WHAT IS KNOWN ALREADY

Based on the concept of multiple follicular waves, the combination of two stimulations in the same ovarian cycle has gained interest in patients with a low ovarian reserve. This so-called dual stimulation approach is usually characterized by a discontinuation of FSH administration for ∼5 days and appears to have a favourable impact on the number of retrieved oocytes without affecting the embryo quality or ploidy status. The outcomes of dual uninterrupted OS have not yet been studied.

STUDY DESIGN, SIZE, DURATION

This was an open-label randomized controlled trial (RCT) with superiority design, performed in a single tertiary centre. Subjects were randomized with a 1:1 allocation into two groups between October 2019 and September 2021. All patients underwent a conventional stimulation with recombinant FSH. When two or more follicles of 17 mm were present, the final inclusion criterion was assessed; randomization occurred only in the presence of ≤9 follicles of ≥11 mm. In Group A, ovulation was triggered with hCG, and oocyte retrieval (OR) was performed 34-36 h later, followed by a fresh single or double embryo transfer (SET or DET) on Day 3/5. In Group B, ovulation was triggered with GnRH agonist, followed by another OS, without discontinuation of the FSH administration. In the presence of one or more follicles of ≥17 mm, the second stimulation was completed with hCG. A freeze-all strategy (Day 3/5) was applied for both retrievals, followed by transfer of one or two embryos in an artificially prepared frozen-thawed cycle. In the absence of one or more follicles of ≥17 mm after 13 additional days of stimulation, the second cycle was cancelled. All ORs were executed by a senior fertility specialist who was blinded for the first treatment, and all follicles >10 mm were aspirated, according to routine clinical practice. The primary outcome was the total number of MII oocytes. Patients were followed up until all embryos were transferred, or until live birth was achieved. Other secondary outcomes included the number of cumulus-oocyte complexes (COCs), the number of good quality embryos (Day 3/5), the ongoing pregnancy rate, and gonadotropin consumption.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients between 25 and 40 years old, with an anti-Müllerian hormone level of ≤1.5 ng/ml, antral follicle count of ≤6, or ≤5 oocytes after a previous stimulation, were included. At the start, 70 patients were eligible for participation in the trial, of whom 48 patients fulfilled the final inclusion criterium and were randomized. After drop-out of two patients, 23 patients were randomized to a single round of OS (Group A), and 23 patients were randomized to two uninterrupted rounds of OS (Group B).

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline characteristics were similar between both groups. The cumulative number of COCs and MII oocytes after completion of the second OR was similar in Group A and Group B [5.3 ± 2.7 versus 5.3 ± 3.0 (P = 0.95); 4.1 ± 2.4 versus 4.3 ± 2.7 (P = 0.77)]. Likewise, a comparable number of excellent and good quality embryos was available on Day 3 (3.0 ± 2.0 versus 2.7 ± 2.0; P = 0.63). In Group B, the cancellation rate due to insufficient response to the second round of stimulation was 39.1% (9/23). When focusing on the first stimulation in both groups, there were no significant differences regarding basal FSH, gonadotropin consumption, and the number of preovulatory follicles. After the first OR, the mean number of COC and MII oocytes was significantly higher in Group A (who had hCG triggering), compared to Group B (who had GnRH agonist triggering) [5.3 ± 2.7 versus 3.3 ± 2.2; difference 95% CI (0.54 to 3.45), P = 0.004 and 4.1 ± 2.4 versus 3.0 ± 2.2; difference 95% CI (-0.15 to 2.6), P = 0.05, respectively]. Likewise, the number of excellent and good quality embryos on Day 3 was significantly higher (3.0 ± 2.0 versus 1.9 ± 1.7; P = 0.02) in Group A.

LIMITATIONS, REASONS FOR CAUTION

This study was powered to demonstrate superiority for the number of MII oocytes after dual stimulation. Investigating the impact of dual stimulation on pregnancy rates would have required a larger sample size. Furthermore, the heterogeneity in embryo vitrification and transfer policies precluded a correct comparison of embryologic outcomes between both groups.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first RCT investigating the role of continuous stimulation with double aspiration in low responders. Our results show no statistically significant differences in the cumulative number of MII oocytes between one conventional stimulation with fresh ET and two consecutive stimulations with a freeze-only approach. Furthermore, the observed suboptimal oocyte yield after agonist ovulation triggering in low responders in the dual uninterrupted OS group is a reason for concern and further scrutiny, given that previous RCTs have shown similar outcomes in normal and high responders after hCG and GnRH agonist triggers.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by a research grant from Organon. H.T. received honoraria for lectures and presentations from Abbott, Cooper Surgical, Gedeon-Richter, Cook, Goodlife, and Ferring. L.B. received fees for lectures from Merck & Organon and support for attending ESHRE 2023. M.D.V. reports fees for lectures from Ferring, Merck, Organon, IBSA, Gedeon Richter, and Cooper Surgical and support for attending ASRM 2023. S.M. received honoraria for lectures and presentations from Abbott, Cooper Surgical, Gedeon-Richter, IBSA, and Merck. C.B. was on the Advisory board and received consulting fees from Theramex and received honoraria for lectures and presentations from Abbott, Ferring, Gedeon-Richter, IBSA, and Merck.

TRIAL REGISTRATION NUMBER

NCT03846544.

TRIAL REGISTRATION DATE

19 February 2019.

DATE OF FIRST PATIENT’S ENROLMENT

28 October 2019.

Enzymatic tissue processing after testicular biopsy in non-obstructive azoospermia enhances sperm retrieval

STUDY QUESTION

What is the added value of enzymatic processing of testicular biopsies on testicular sperm retrieval (SR) rates for patients with non-obstructive azoospermia (NOA)?

SUMMARY ANSWER

In addition to mechanical mincing, enzymatic digestion increased SR rates in testicular biopsies of NOA patients.

WHAT IS KNOWN ALREADY

Many studies focus on the surgical approach to optimize recovery of testicular sperm in NOA, and in spite of that, controversy still exists about whether the type of surgery makes any difference as long as multiple biopsies are taken. Few studies, however, focus on the role of the IVF laboratory and the benefit of additional lab procedures, e.g. enzymatic digestion, in order to optimize SR rates.

STUDY DESIGN SIZE DURATION

This retrospective single-center cohort study included all patients who underwent their first testicular sperm extraction (TESE) by open multiple-biopsy method between January 2004 and July 2022. Only patients with a normal karyotype, absence of Y-q deletions and a diagnosis of NOA based on histology were included. The primary outcome was SR rate after mincing and/or enzymes. The secondary outcome was cumulative live birth (CLB) after ICSI with fresh TESE and subsequent ICSI cycles with frozen TESE.

PARTICIPANTS/MATERIALS SETTING METHODS

Multiple biopsies were obtained from the testis, unilaterally or bilaterally, on the day of oocyte retrieval. Upon mechanical mincing, biopsies were investigated for 30 min; when no or insufficient numbers of spermatozoa were observed, enzymatic treatment was performed using Collagenase type IV. Multivariable regression analysis was performed to predict CLB per TESE by adjusting for the following confounding factors: male FSH level, female age, and requirement of enzymatic digestion to find sperm.

MAIN RESULTS AND THE ROLE OF CHANCE

We included 118 patients, of whom 72 (61.0%) had successful SR eventually. Spermatozoa were retrieved after mechanical mincing for 28 patients (23.7%; 28/118) or after additional enzymatic digestion for another 44 patients (37.2%; 44/118). Thus, of the 90 patients requiring enzymatic digestion, sperm were retrieved for 44 (48.9%). Male characteristics were not different between patients with SR after mincing or enzymatic digestion, in regard to mean age (34.5 vs 34.5 years), testis volume (10.2 vs 10.6 ml), FSH (17.8 vs 16.9 IU/l), cryptorchidism (21.4 vs 34.1%), varicocele (3.6 vs 4.6%), or histological diagnosis (Sertoli-cell only 53.6 vs 47.7%, maturation arrest 21.4 vs 38.6%, sclerosis/atrophy 25.0 vs 13.6%).Of the 72 patients with sperm available for ICSI, 23/72 (31.9%) achieved a live birth (LB) after the injection with fresh testicular sperm (and fresh or frozen embryo transfers). Of the remaining 49 patients without LB, 34 (69.4%) had supernumerary testicular sperm frozen. Of these 34 patients, 19 (55.9%) continued ICSI with frozen testicular sperm, and 9/19 (47.4%) had achieved an LB after ICSI with frozen testicular sperm. Thus, the total CLB was 32/118 (27.1%) per TESE or 32/72 (44.4%) per TESE with sperm retrieved.Of the female characteristics (couples with sperm available), only female age (30.3 vs 32.7 years; P = 0.042) was significantly lower in the group with a LB, compared to those without.The CLB with testicular sperm obtained after enzymatic digestion was 31.8% (14/44), while the CLB with sperm obtained after mincing alone was 64.3% (18/28). Multivariable logistic regression analysis showed that when enzymatic digestion was required, it was associated with a significant decrease in CLB per TESE (OR: 0.23 (0.08-0.7); P = 0.01).

LIMITATIONS REASONS FOR CAUTION

Limitations of the study are related to the retrospective design. However, the selection of only patients with NOA, and specific characteristics (normal karyotype and absence Y-q deletion) and having their first TESE, strengthens our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Enzymatic processing increases the SR rate from testicular biopsies of NOA patients compared to mechanical mincing only, demonstrating the importance of an appropriate laboratory protocol. However, NOA patients should be counseled that when sperm have been found after enzymatic digestion, their chances to father a genetically own child may be lower compared to those not requiring enzymatic digestion.

STUDY FUNDING/COMPETING INTERESTS

None reported.

TRIAL REGISTRATION NUMBER

N/A.

Assessment of progesterone levels on the day of pregnancy test determination: A novel concept toward individualized luteal phase support

RESEARCH QUESTION

The main objective of the study is to define the optimal trade-off progesterone (P4) values on the day of embryo transfer (ET), to identify low P4-human chorionic gonadotropin (hCG), and to establish whether P4 supplementation started on the hCG day can increase the success rate of the frozen embryo transfer (FET) cycle.

DESIGN

A single-center, cohort, retrospective study with 664 hormone replacement therapy (HRT)-FET cycles analyzed female patients who received vaginal 600 mg/day of P4 starting from 6 days before the FET, had normal P4 values on the day before ET, and whose P4 on the day of the pregnancy test was assessed.

RESULTS

Of the 664 cycles, 69.6% of cycles showed P4 ≥ 10.6 ng/ml, while 30.4% showed P4 < 10.6 ng/ml on the day of the hCG. Of the 411 chemical pregnancies detected, 71.8% had P4-hCG ≥ 10.6 ng/ml (group A), while 28.2% had P4-hCG < 10.6 ng/ml. Of the cycles with P4-hCG < 10.6 ng/ml, 64.7% (group B) were supplemented with a higher dose of vaginal P4 (1,000 mg/day), while 35.3% (group C) were maintained on the same dose of vaginal micronized P4. The live birth rate was 71.9%, 96%, and 7.3% for groups A, B, and C, respectively.

CONCLUSION

The likelihood to detect P4-hCG < 10.6 ng/ml decreased as the level of serum P4 the day before ET increased. The live birth rate (LBR) was shown to be significantly lower when P4 was low and not supplemented.

Impact of cell loss after warming of human vitrified day 3 embryos on obstetric outcome in single frozen embryo transfers

PURPOSE

Does cell loss (CL) after vitrification and warming (V/W) of day 3 embryos have an impact on live birth rate (LBR) and neonatal outcomes?

METHOD

This retrospective analysis includes cleavage stage day 3 embryos vitrified/warmed between 2011 and 2018. Only single vitrified/warmed embryo transfers were included. Pre-implantation genetic screening, oocyte donation, and age banking were excluded from the analysis. The sample was divided into two groups: group A (intact embryo after warming) and group B (≤ 50% blastomere loss after warming).

RESULTS

On the total embryos (n = 2327), 1953 were fully intact (83.9%, group A) and 374 presented cell damage (16.1%, group B). In group B, 62% (232/374) of the embryos had lost only one cell. Age at cryopreservation, cause of infertility, insemination procedure, and semen origin were comparable between the two groups. The positive hCG rate (30% and 24.3%, respectively, for intact vs CL group, p = 0.028) and LBR (13.7% and 9.4%, respectively, for intact vs CL group, p = 0.023) per warming cycle were significantly higher for intact embryos. However, LBR per positive hCG was equivalent between intact and damaged embryos (45.6% vs 38.5%, respectively, p = 0.2). Newborn measurements (length, weight, and head circumference at birth) were comparable between the two groups. Multivariate logistic regression showed that the presence of CL is not predictive for LB when adjusting for patients' age.

CONCLUSIONS

LBR is significantly higher after transfer of an intact embryo compared to an embryo with CL after warming; however, neonatal outcomes are comparable between the two groups.

O-241 Elevated serum progesterone levels before frozen embryo transfer do not negatively impact reproductive outcomes: a large retrospective cohort study

Study question

Do patients with high serum progesterone levels before frozen embryo transfer (FET) under hormonal replacement therapy (HRT) present worse reproductive outcomes?

Summary answer

Elevated serum progesterone levels before FET in artificially prepared cycles with vaginal or vaginal plus subcutaneous progesterone do not impair reproductive outcomes.

What is known already

Low serum progesterone levels before FET do negatively affect reproductive outcomes in terms of live birth rate. However, there is not robust data regarding the impact of high serum progesterone levels in the luteal phase of patients who undergo HRT for FET.

Study design, size, duration

Retrospective cohort study of 3183 blastocyst FET cycles under HRT performed in a university-affiliated fertility centre between March 2009 and December 2020. All the cycles presented adequate serum progesterone levels before FET (≥10.6 ng/ml). A total of 1360 cycles corresponded to frozen homologous embryo transfer (ET) (hom-FET), 1024 were euploid ET (eu-FET) after preimplantational genetic testing for aneuploidies (PGT-A), and 799 cycles were frozen heterologous ET (het-FET). The primary objective was live birth rate (LBR).

Participants/materials, setting, methods

Standard HRT was used. Luteal phase was covered with vaginal progesterone 200 mg/8h, or vaginal plus a daily subcutaneous injection of progesterone (25 mg). Serum progesterone levels were measured the day before FET. Elevated progesterone levels were considered in the 90th and 95th centiles. A generalized additive model (GAM) was performed to study the functional relationships between progesterone and LBR. A multivariable logistic regression was used to evaluate the effect of high progesterone over LBR.

Main results and the role of chance

Mean serum progesterone level before FET was 16.77±8.43 ng/ml. Progesterone levels were significantly higher in the group under vaginal plus subcutaneous progesterone (21.87±14.17 vs. 15.56±5.72, p &lt; 0.001). No differences in clinical pregnancy, miscarriage and LBR were found according to the use of vaginal or vaginal plus subcutaneous progesterone for each of the groups (hom-FET, eu-FET and het-FET). Live birth rates were comparable among patients in the highest centile of serum progesterone levels (≥p90, ≥22.33 ng/ml) and the rest of patients (p &lt; 90) (43.9 vs 41.3%; p = 0.381). Patients with progesterone levels ≥p90 presented lower BMI compared to those in the lower centiles (&lt;p90) (22.62±3.82 vs. 23.32±4.06; P = 0.009). After dividing patients in deciles according to serum progesterone levels before, no differences in LBR were observed among groups (P = 0.938). No association was observed with GAM model between progesterone levels and LBR. A multivariable logistic regression adjusted by oocyte age, type of treatment and number of embryos transferred was applied for centile 90 and centile 95 of progesterone, and showed that serum progesterone in their highest levels did not negatively impact LBR.

Limitations, reasons for caution

The main limitation of this study is its retrospective design. The results only apply for patients under HRT with vaginal micronized progesterone alone or plus subcutaneous progesterone. Progesterone determination was measured before blastocyst FET. Extrapolation to other HRT protocols or timings of progesterone measurement needs to be validated.

Wider implications of the findings

The results of this study suggest that once a threshold of serum progesterone before FET is achieved, progesterone levels are not predictive of the clinical outcome. Actually, LBR are not negatively affected when progesterone levels are found in their highest centiles after luteal phase rescue with vaginal plus subcutaneous progesterone.

Trial registration number

Not applicable

P-403 Progesterone supplementation in frozen embryo transfer with hormonal replacement therapy is associated with a higher incidence of macrosomia

Study question

Is there an impact of increased progesterone (P4) supplementation in hormone replacement therapy (HRT) frozen embryo transfer (FET) on obstetrical and neonatal outcomes?

Summary answer

Increased P4 supplementation from the day of FET is associated with a significantly higher risk of macrosomia and a slightly higher risk of preeclampsia.

What is known already

The most widely used method for endometrial preparation prior to FET is HRT, a sequential regimen with E2 and P4, which aims to mimic the endocrine exposure of the endometrium of the physiological cycle. However, in ∼40% of the patients undergoing HRT-FET cycles P4 levels before FET remain low and this may negatively affect pregnancy rates. Although recent prospective studies have shown that additional P4 supplementation in case of low serum P4 levels results in excellent reproductive outcomes, no data exist concerning the potential effect of this extra amount of P4 on obstetrical and neonatal outcomes

Study design, size, duration

This is a single-centre, retrospective-observational study. Women undergoing HRT-FET treatment meeting the inclusion criteria were allocated to one of the 2 study groups according to the P4 supplementation. Group A (277) included women with adequate levels (&gt;10.6 ng/ml) of P4, while group B (129) included women who received P4 supplementation due to inadequate levels of P4 (&lt;10.6 ng/ml) on the day before the FET. All FET-HRT cycles were performed between February 2018 and December 2020.

Participants/materials, setting, methods

All patients received micronized P4 (200 mg trice a day) starting six days prior to the FET and continued until 10 weeks of pregnancy. In case P4&lt;10.6 ng/ml, P4 supplementation was initiated rather with 400mg more micronized P4 (15%) or with subcutaneous P4 (25mg more/once a day) (85%). Only patients with day5-embryos, known P4 levels prior to FET, known obstetrical and neonatal outcomes were included. Multivariable-logistic-model was fitted for macrosomia after adjusting for confounding variables.

Main results and the role of chance

Patients’ age at oocyte retrieval was 33.5 and 33.6 years (p = 0.833), while the age at delivery was 39.9 and 39.1 years (p = 0.099), respectively for groups A and B. The incidence of diabetes, hypertension, autoimmune diseases, coagulation, and kidney disorders was comparable for both arms. The mean value of P4 was 16 ± 7.7 and 8.2 ± 1.9, respectively for groups A and B. The mean gestational length was 39 weeks in both arms, with comparable rates of premature deliveries (delivery &lt;37 weeks respectively 4.3% and 3.1 % for group A and B; p = 0.553). The rate of cesarean-section was 56% vs 47.3%, respectively for groups A and B (p = 0.103); there were 5 cases of pre-eclampsia in group A and 7 in group B (1.8% vs 5.4%; p = 0.059). The incidence of macrosomia was significantly higher in group B (6.1% vs 12.4%; P = 0.031). Similarly, group B had a higher rate of BGA-big for gestational age- babies (9.7 vs 15.5, p = 0.091). In terms of weight at delivery, pH, Apgar, and sex the two groups were comparable. Multivariable-logistic regression showed an association between macrosomia and P4 supplementation, adjusting for potential confounders such as sex, gestational diabetes, and weeks of gestation (OR 2.3, 95% CI 1.1-4.8).

Limitations, reasons for caution

The main limitation of this study is its retrospective nature. Other potential limitations are the small sample size to detect obstetrical diseases with low incidence, such as preeclampsia. Furthermore, in our study population the PE rate is lower than in the general population, due to socioeconomic-conditions, race, and previous morbidity.

Wider implications of the findings

P4-supplemented patients have a higher risk of macrosomia and a tendency for a higher risk of preeclampsia. However, more studies are needed to confirm the present exploratory findings and explain the possible physiological mechanisms underlying the association between progesterone supplementation on macrosomia and preeclampsia.

Trial registration number

NA

O-069 Does dual stimulation with continuous FSH administration increase the total number of metaphase II oocytes in poor responders?

Study question

Is there an increase in the total number of metaphase II (MII) oocytes between a conventional ovarian stimulation and a dual uninterrupted stimulation?

Summary answer

Dual stimulation with continuous follicle stimulating hormone (FSH) administration is not superior to conventional stimulation in terms of number of MII oocytes.

What is known already

In the last decade, the concept of multiple follicular waves during one menstrual cycle has gained a lot of interest. Translated into clinical practice, combining two stimulations in the same ovarian cycle has appeared beneficial with regard to the number of retrieved oocytes, without affecting the embryo quality or ploidy status. Usually, this so-called dual stimulation approach is characterized by a discontinuation of FSH administration for approximately 5 days between two consecutive stimulations. The role of dual uninterrupted ovarian stimulation has not yet been studied.

Study design, size, duration

This was an open-label randomized controlled trial (RCT) with superiority design, performed in a single tertiary center. Power analysis indicated a required sample of 46 patients to detect superiority (defined as two surplus MII oocytes) of the dual stimulation group. Between October 2020 and September 2021, 70 patients were screened, 48 were randomized and 46 completed the study.

Participants/materials, setting, methods

Women aged 25-40 with a serum anti-Müllerian hormone (AMH) level of ≤ 1.5 ng/mL, antral follicle count (AFC) of ≤ 6, or ≤ 5 oocytes after a previous stimulation, were eligible for inclusion. Randomization occurred only in case of ≤ 9 follicles of ≥ 11mm on the trigger day. In the control group, patients underwent one round of ovarian stimulation and oocyte retrieval only, while the study group had two uninterrupted rounds of ovarian stimulation and two retrievals.

Main results and the role of chance

Baseline characteristics were similar between both groups. The cumulative number of COC and MII oocytes after completion of the second oocyte retrieval was similar in the control and study group [5.3 ± 2.7 versus 5.3 ± 3.1 [difference 95%CI (-1.7 to 1.7), p = 0.92] and 4.1 ± 2.5 versus 4.3 ± 2.7 [difference 95%CI (-1.7 to 1.3), p = 0.82]. Likewise, a comparable number of good quality embryos at day 3 was available (3.0 ± 2.0 versus 2.7 ± 2., p = 0.63). In the study group, the cancellation rate due to insufficient response to the second round of stimulation was 39.1%.

When focusing on the first stimulation in both groups, there were no significant differences regarding basal FSH, FSH consumption and the number of preovulatory follicles. After the first oocyte retrieval, the mean number of COC and MII oocytes was significantly higher in the control group (who had human chorionic gonadotropin (hCG) triggering), compared to the study group (who had Gonadotropin Releasing Hormone (GnRH) agonist triggering) (5.3 ± 2.7 versus 3.3 ± 2.2, p = 0.004 and 4.2 ± 2.4 versus 2.9 ± 2.2, p = 0.05). Likewise, the number of good quality embryos on day 3 was significantly higher (3.0 ± 2.0 versus 1.9 ± 1.7, p = 0.04).

Limitations, reasons for caution

This study was powered to demonstrate superiority for number of MII oocytes. Investigating the impact of dual stimulation on pregnancy rates would have required a larger sample size.

Wider implications of the findings

The observed suboptimal oocyte yield after agonist triggering in poor responders is a reason for concern and further scrutiny, given that previous RCTs have shown similar outcomes in normal and high responders after hCG and GnRH agonist trigger.

Trial registration number

NCT03846544

P–318 Short (seven days) versus conventional (fourteen days) estrogen priming in an artificial frozen embryo transfer cycle: a randomised controlled trial

Study question

What is the impact of seven days versus fourteen days’ estrogen (E2) priming on the clinical outcome of frozen-embryo-transfer in artificially prepared endometrium (FET-HRT) cycles?

Summary answer

No significant difference in clinical/ongoing pregnancy rate was observed when comparing 7 versus 14 days of estrogen priming before starting progesterone (P) supplementation.

What is known already

One (effective) method for endometrial preparation prior to frozen embryo transfer is hormone replacement therapy (HRT), a sequential regimen with E2 and P, which aims to mimic the endocrine exposure of the endometrium in a physiological cycle. The average duration of E2 supplementation is generally 12–14 days, however, this protocol has been arbitrarily chosen whereas, the optimal duration of E2 implementation remains unknown.

Study design, size, duration

This is a single-center, randomized, controlled, open-label pilot study. All FET-HRT cycles were performed in a tertiary centre between October 2018 and December 2020. Overall, 150 patients were randomized of whom 132 were included in the analysis after screening failure and drop-out.

Participants/materials, setting, methods

The included patients were randomized into one of 2 groups; group A (7 days of E2 prior to P supplementation) and group B (14 days of E2 prior to P supplementation). Both groups received blastocyst stage embryos for transfer on the 6th day of vaginal P administration. Pregnancy was assessed by an hCG blood test 12 days after FET and clinical pregnancy was confirmed by transvaginal ultrasound at 7 weeks of gestation.

Main results and the role of chance

Following the exclusion of drop-outs and screening failures, 132 patients were finally included both in group A (69 patients) or group B (63 patients). Demographic characteristics for both groups were comparable. The positive pregnancy rate was 46.4% and 53.9%, (p 0.462) for group A and group B, respectively. With regard to the clinical pregnancy rate at 7 weeks, no statistically significant difference was observed (36.2% vs 36.5% for group A and group B, respectively, p = 0.499). The secondary outcomes of the study (biochemical pregnancy, miscarriage and live birth rate) were also comparable between the two arms for both PP and ITT analysis. Multivariable logistic regression showed that the HRT scheme is not associated with pregnancy rate, however, the P value on the day of ET is significantly associated with the pregnancy outcome.

Limitations, reasons for caution

This study was designed as a proof of principle trial with a limited study population and therefore underpowered to determine the superiority of one intervention over another. Instead, the purpose of the present study was to explore trends in outcome differences and to allow us to safely design larger RCTs.

Wider implications of the findings: The results of this study give the confidence to perform larger-scale RCTs to confirm whether a FET-HRT can be performed safely in a shorter time frame, thus, reducing the TTP, while maintaining comparable pregnancy and live birth rates.

Trial registration number

NCT03930706

P–672 Higher pregnancy outcomes in patients undergoing embryo transfer-under hormonal replacement therapy where an individualised Progesterone supplementation was applied on the day of β-hCG

Study question

Does progesterone-supplementation (PS) from the day of β-hCG assessment improve pregnancy rates in embryo transfer-under hormonal replacement therapy (ET-HRT) in patient with Progesterone (P)&lt;10.6 ng/mL?

Summary answer

Reduced P on the β-hCG day is associated with lower pregnancy-rates and higher miscarriage-rate. PS from the same day showed significant increase of reproductive outcomes.

What is known already

Up until now, in ART, very little has been done to understand whether the P intake should be personalized during the luteal phase. Most recent studies on the topic showed that low P levels on the day of ET-HRT or on the day before are associated with decreased pregnancy rates; however, when low P values are supplemented from the day before embryo-transfer (ET), similar results to cases with adequate P are reported. Nevertheless, little is known about the association between low P level, on the day of β-hCG (P- β-hCG) and PS from this day in ET-HRT, and pregnancy outcomes.

Study design, size, duration

This is a single centre, cohort, retrospective study conducted at a university-affiliated fertility centre between January 2018 and June 2020 where PS took place from the day of positive β-hCG determination when P &lt; 10.6 ng/mL. In total 789 ET-HRT cycles were analysed of which 239 were performed in both fresh and frozen heterologous ET-HRT (het-ET), 336 in homologous ET-HRT (hom-FET) and 214 in euploid ET-HRT (eu-FET) after preimplantation genetic testing for aneuploidies IVF cycles (PGT-A).

Participants/materials, setting, methods

Women undergoing ET-HRT with normal P (&gt;10.6ng/mL) on the day before ET were screened for P on the day of β-hCG. All women received vaginal P 200 mg/8 hours for the second part of HRT. PS was performed by adding P to the HRT when P- β-hCG was considered low (&lt;10.6 ng/mL). Primary outcome: ongoing-pregnancy-rate (OPR); secondary outcome: miscarriage-rate (MR). Both were evaluated by considering PS on the day of β-hCG as a categorical variable.

Main results and the role of chance

Patients characteristics were comparable between groups (het-ET, hom-FET and eu-FET) although significantly lower body mass index was found when P- β-hCG&gt;10.6 ng/mL compared to the subgroup with P- β-hCG&lt;10.6 ng/mL and no PS (p = 0.012). Overall clinical pregnancy rate was 52.1% with no-significant differences between groups (48.5% in het-ET, 52.9% in hom-FET and 54.7% in eu-FET). P- β-hCG was considered as adequate in 75.7% (311/411) ET-HRT with positive β-hCG and low in 24.3% (100/411), with no differences between groups. In case of positive β-hCG and P- β-hCG &gt;10.6 ng/mL, OPR was 83.6% and MR was 16.4%, with no-significant differences between groups. Among the 100 low P- β-hCG, 80 ET-HRT received PS. In this subgroup OPR was 96.2% and MR was 3.8%, with no-significant differences between groups. In 20 out of 100 ET with P- β-hCG &lt;10.6 ng/mL, no PS was added for different reasons. This group showed the lowest OPR (30%) and the highest MR (70%), again with no between-group differences according to het-ET, hom-FET or eu-FET. Miscarriage rate was significantly higher (p &lt; 0.001) when P- β-hCG was &lt;10.6 ng/mL and no PS was added to HRT compared to P- β-hCG &lt;10.6 ng/mL but with PS, and also compared to the P- β-hCG &gt;10.6 ng/mL group.

Limitations, reasons for caution

The main limitation of the study is due to its retrospective nature and the small sample of patients with P- β-hCG&lt;10.6 ng/mL that was not supplemented. Furthermore, the cut-off of P- β-hCG was arbitrarily decided upon previous studies, and lastly different routes of administration were considered for the PS.

Wider implications of the findings: The results of this study showed that individualization of Progesterone supplementation in ET-HRT may be a crucial turn point in order to increase the pregnancy rates and decrease the miscarriage rates. An adequate PS should be considered in case of low P- β-hCG levels for both het-ET, hom-FET and eu-FET.

Trial registration number

Not applicable

Is a freeze-all policy the optimal solution to circumvent the effect of late follicular elevated progesterone? A multicentric matched-control retrospective study analysing cumulative live birth rate in 942 non-elective freeze-all cycles

STUDY QUESTION

Is late follicular elevated progesterone (LFEP) in the fresh cycle hindering cumulative live birth rates (CLBRs) when a freeze only strategy is applied?

SUMMARY ANSWER

LFEP in the fresh cycle does not affect the CLBR of the frozen transfers in a freeze only approach, nor the embryo freezing rate.

WHAT IS KNOWN ALREADY

Ovarian stimulation promotes the production of progesterone (P) which has been demonstrated to have a deleterious effect on IVF outcomes. While there is robust evidence that this elevation produces impaired endometrial receptivity, the impact on embryo quality remains a matter of debate. In particular, previous studies have shown that LFEP is associated with a hindered CLBR. However, most clinical insight on the effect of progesterone on embryo quality in terms of CLBRs have focused on embryo transfers performed after the fresh transfer, thus excluding the first embryo of the cohort. To be really informative on the possible detrimental effects of LFEP, evidence should be derived from freeze-all cycles where no fresh embryo transfer is performed in the presence of progesterone elevation, and the entire cohort of embryos is cryopreserved.

STUDY DESIGN, SIZE, DURATION

This was a matched case-control, multicentre (three centres), retrospective analysis including all GnRH antagonist ICSI cycles in which a freeze all (FA) policy of embryos on day 3/5/6 of embryonic development was applied between 2012 and 2018. A total of 942 patients (471 cases with elevated P and 471 matched controls with normal P values) were included in the analysis. Each patient was included only once.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The sample was divided according to the following P levels on the day of ovulation triggering: <1.50 ng/ml and ≥1.50 ng/ml. The matching of the controls was performed according to age (±1 year) and number of oocytes retrieved (±10%). The main outcome was CLBR defined as a live-born delivery after 24 weeks of gestation.

MAIN RESULTS AND THE ROLE OF CHANCE

The baseline characteristics of the two groups were similar. Estradiol levels on the day of trigger were significantly higher in the elevated P group. There was no significant difference in terms of fertilisation rate between the two groups. The elevated P group had significantly more cleavage stage frozen embryos compared to the normal P group while the total number of cryopreserved blastocyst stage embryos was the same. The CLBR did not differ between the two study groups (29.3% and 28.2% in the normal versus LFEP respectively, P = 0.773), also following confounder adjustment using multivariable GEE regression analysis (accounting for age at oocyte retrieval, total dose of FSH, progesterone levels on the day of ovulation trigger, day of freezing, at least one top-quality embryo transferred and number of previous IVF cycles, as the independent variables).

LIMITATIONS, REASONS FOR CAUTION

This is a multicentre observational study based on a retrospective data analysis. Better extrapolation of the results could be validated by performing a prospective analysis.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study demonstrating that LFEP in the fresh cycle does not hinder CLBR of the subsequent frozen cycles in a FA approach. Thus, a FA strategy circumvents the issue of elevated P in the late follicular phase.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study. Throughout the study period and manuscript preparation, authors were supported by departmental funds from: Centre for Reproductive Medicine, Brussels, Belgium; Infertility Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; Centro Scienze Natalità, San Raffaele Scientific Institute, Milan, Italy; and IVI-RMA, Lisbon, Portugal. E.S. has competing interests with Ferring, Merck-Serono, Theramex and Gedeon-Richter outside the submitted work. E.P. reports grants from Ferring, grants and personal fees from Merck-Serono, grants and personal fees from MSD and grants from IBSA outside the submitted work. All the other authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Expanding the time interval between ovulation triggering and oocyte injection: does it affect the embryological and clinical outcome?

STUDY QUESTION

Is the time interval between ovulation triggering and oocyte denudation/injection associated with embryological and clinical outcome after ICSI?

SUMMARY ANSWER

Expanding the time interval between ovulation triggering and oocyte denudation/injection is not associated with any clinically relevant impact on embryological or clinical outcome.

WHAT IS KNOWN ALREADY

The optimal time interval between ovulation triggering and insemination/injection appears to be 38-39 h and most authors agree that an interval of >41 h has a negative influence on embryological and clinical pregnancy outcomes. However, in ART centres with a heavy workload, respecting these exact time intervals is frequently challenging. Therefore, we questioned to what extent a wider time interval between ovulation triggering and oocyte injection would affect embryological and clinical outcome in ICSI cycles.

STUDY DESIGN, SIZE, DURATION

A single-centre retrospective cohort analysis was performed including 8811 ICSI cycles from 2010 until 2015. Regarding the time interval between ovulation triggering and oocyte injection, seven categories were considered: <36 h, 36 h, 37 h, 38 h, 39 h, 40 h and ≥41 h. In all cases, denudation was performed immediately prior to injection. The main outcome measures were oocyte maturation, fertilization and embryo utilization rate (embryos adequate for transfer or cryopreservation) per fertilized oocyte. Clinical pregnancy rate (CPR) and live birth rate (LBR) were considered as secondary outcomes. Utilization rate, CPR and LBR were subdivided into two groups according to the day of embryo transfer: Day 3 or Day 5.

PARTICIPANTS/MATERIALS, SETTING, METHODS

During the study period, oocyte retrieval was routinely performed 36 h post-triggering except in the <36 h group. The interval of <36 h occurred only if OR was carried out before the planned 36 h trigger interval and was followed by immediate injection. Only cycles with fresh autologous gametes were included. The exclusion criteria were: injection with testicular/epididymal sperm, managed natural cycles, conventional IVF, combined conventional IVF/ICSI, preimplantation genetic testing and IVM cycles. Female age, number of oocytes, pre-preparation sperm concentration, post-preparation sperm concentration and motility, day of transfer, number of embryos transferred and quality of the best embryo transferred were identified as potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the seven interval groups, adjusted mean maturation rates ranged from 76.4% to 83.2% and differed significantly (P < 0.001). Similarly, there was a significant difference in adjusted mean fertilization rates (range 69.2-79.3%; P < 0.001). The adjusted maturation and fertilization rates were significantly higher when denudation/injection was performed >41 h post-triggering compared to 38 h post-triggering (reference group). Oocyte denudation/injection at <36 h post-triggering had no significant effect on maturation, fertilization or embryo utilization rates compared to injection at 38 h. No effect of the time interval was observed on CPRs and LBRs, after adjusting for potential confounders. When oocyte injection was performed before 36 h the adjusted analysis showed that compared to 38 h after ovulation triggering the chance of having a live birth tends to be lower although the difference was not statistically significant (odds ratio 0.533, 95% CI: 0.252-1.126; P = 0.099). Injection ≥41 h post-triggering did not affect LBR compared to injection at 38 h post-ovulation.

LIMITATIONS, REASONS FOR CAUTION

As this is a large retrospective study, the influence of uncontrolled variables cannot be excluded. These results should not be extrapolated to other ART procedures such as IVM, conventional IVF or injection with testicular/epididymal sperm.

WIDER IMPLICATIONS OF THE FINDINGS

Our results indicate that the optimal injection time window may be less stringent than previously thought as both embryological and clinical outcome parameters were not significantly affected in our analysis. This is reassuring for busy ART centres that might not always be able to follow strict time intervals.

STUDY FUNDING/COMPETING INTEREST(S)

No funding. The authors declare no conflict of interest related to the present study.

TRIAL REGISTRATION NUMBER

N/A.

The proliferative phase endometrium in IVF/ICSI: an in-cycle molecular analysis predictive of the outcome following fresh embryo transfer

STUDY QUESTION

Does an early proliferative phase endometrial biopsy harvested during ovarian stimulation harbour information predictive of the outcome following fresh embryo transfer (ET) in that same cycle?

SUMMARY ANSWER

Transcriptome analysis of the whole-tissue endometrium did not reveal significant differential gene expression (DGE) in relation to the outcome; however, the secretome profile of isolated, cultured and in vitro decidualized endometrial stromal cells (EnSCs) varied significantly between patients who had a live birth compared to those with an implantation failure following fresh ET in the same cycle as the biopsy.

WHAT IS KNOWN ALREADY

In the majority of endometrial receptivity research protocols, biopsies are harvested during the window of implantation (WOI). This, however, precludes ET in that same cycle, which is preferable as the endometrium has been shown to adapt over time. Endometrial biopsies taken during ovarian stimulation have been reported not to harm the chances of implantation, and in such biopsies DGE has been observed between women who achieve pregnancy versus those who do not. The impact of the endometrial proliferative phase on human embryo implantation remains unclear, but deserves further attention, especially since in luteal phase endometrial biopsies, a transcriptional signature predictive for repeated implantation failure has been associated with reduced cell proliferation, possibly indicating proliferative phase involvement. Isolation, culture and in vitro decidualization (IVD) of EnSCs is a frequently applied basic research technique to assess endometrial functioning, and a disordered EnSC secretome has previously been linked with failed implantation.

STUDY DESIGN, SIZE, DURATION

This study was nested in a randomized controlled trial (RCT) investigating the effect of endometrial scratching during the early follicular phase of ovarian stimulation on clinical pregnancy rates after IVF/ICSI. Of the 96 endometrial biopsies available, after eliminating those without fresh ET and after extensive matching in order to minimize the risk of potential confounding, 18 samples were retained to study two clinical groups: nine biopsies of patients with a live birth versus nine biopsies of patients with an implantation failure, both following fresh ET performed in the same cycle as the biopsy. We studied the proliferative endometrium by analysing its transcriptome and by isolating, culturing and decidualizing EnSCs in vitro. We applied this latter technique for the first time on proliferative endometrial biopsies obtained during ovarian stimulation for in-cycle outcome prediction, in an attempt to overcome inter-cycle variability.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RNA-sequencing was performed for 18 individual whole-tissue endometrial biopsies on an Illumina HiSeq1500 machine. DGE was analysed three times using different approaches (DESeq2, EdgeR and the Wilcoxon rank-sum test, all in R). EnSC isolation and IVD was performed (for 2 and 4 days) for a subset of nine samples, after which media from undifferentiated and decidualized cultures were harvested, stored at -80°C and later assayed for 45 cytokines using a multiplex suspension bead immunoassay. The analysis was performed by partial least squares regression modelling.

MAIN RESULTS AND THE ROLE OF CHANCE

After correction for multiple hypothesis testing, DGE analysis revealed no significant differences between endometrial samples from patients who had a live birth and those with an implantation failure following fresh ET. However secretome analysis after EnSC isolation and culture, showed two distinct clusters that clearly corresponded to the two clinical groups. Upon IVD, the secretome profiles shifted from that of undifferentiated cells but the difference between the two clinical groups remained yet were muted, suggesting convergence of cytokine profiles after decidualization.

LIMITATIONS, REASONS FOR CAUTION

Caution is warranted due to the limited sample size of the study and the in vitro nature of the EnSC experiment. Validation on a larger scale is necessary, however, hard to fulfil given the very limited availability of in-cycle proliferative endometrial biopsies outside a RCT setting.

WIDER IMPLICATIONS OF THE FINDINGS

These data support the hypothesis that the endometrium should be assessed not only during the WOI and that certain endometrial dysfunctionalities can probably be detected early in a cycle by making use of the proliferative phase. This insight opens new horizons for the development of endometrial tests, whether diagnostic or predictive of IVF/ICSI treatment outcome.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Fonds Wetenschappelijk Onderzoek (FWO, Flanders, Belgium, 11M9415N, 1 524 417N), Wetenschappelijk Fonds Willy Gepts (WFWG G160, Universitair Ziekenhuis Brussel, Belgium) and the National Medicine Research Council (NMRC/CG/M003/2017, Singapore). There are no conflicts of interests.

TRIAL REGISTRATION NUMBER

NCT02061228.

To trigger or not to trigger ovulation in a natural cycle for frozen embryo transfer: a randomized controlled trial

STUDY QUESTION

Is the clinical pregnancy rate (CPR) following a frozen embryo transfer (FET) in a natural cycle (NC) higher after spontaneous ovulation than after triggered ovulation [natural cycle frozen embryo transfer (NC-FET) versus modified NC-FET]?

SUMMARY ANSWER

The CPR did not vary significantly between the two FET preparation protocols.

WHAT IS KNOWN ALREADY

Although the use of FET is continuously increasing, the most optimal endometrial preparation protocol is still under debate. For transfer in the NC specifically, conflicting results have been reported in terms of the outcome following spontaneous or triggered ovulation.

STUDY DESIGN, SIZE, DURATION

In a tertiary hospital setting, subjects were randomized with a 1:1 allocation into two groups between January 2014 and January 2019. Patients in group A underwent an NC-FET, while in group B, a modified NC-FET was performed with a subcutaneous hCG injection to trigger ovulation. In neither group was additional luteal phase support administered. All embryos were vitrified-warmed on Day 3 and transferred on Day 4 of embryonic development. The primary outcome was CPR at 7 weeks. All patients were followed further until 10 weeks of gestation when the ongoing pregnancy rate (OPR) was defined by the observation of foetal cardiac activity on ultrasound scan. Other secondary outcomes included biochemical pregnancy rate, early pregnancy loss and the number of visits, blood samples and ultrasonographic examinations prior to FET.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 260 patients (130 per study arm) were randomized, of whom 12 withdrew consent after study arm allocation. A total of 3 women conceived spontaneously before initiating the study cycle and 16 did not start for personal or medical reasons. Of the 229 actually commencing monitoring for the study FET cycle, 7 patients needed to be switched to a hormonal replacement treatment protocol due to the absence of follicular development, 12 had no embryo available for transfer after warming and 37 had a spontaneous LH surge before the ovulation trigger could be administered, although they were allocated to group B. Given the above, an intention-to-treat (ITT) analysis was performed taking into account 248 patients (125 in group A and 123 in group B), as well as a per protocol (PP) analysis on a subset of 173 patients (110 in group A and 63 in group B).

MAIN RESULTS AND THE ROLE OF CHANCE

Demographic features were evenly distributed between the study groups, as were the relevant fresh and frozen ET cycle characteristics. According to the ITT analysis, the CPR and OPR in group A (33.6% and 27.2%, respectively) and group B (29.3% and 24.4%, respectively) did not vary significantly [relative risk (RR) 0.87, 95% CI (0.60;1.26), P = 0.46 and RR 0.90, 95% CI (0.59;1.37), P = 0.61, respectively]. Biochemical pregnancy rate and early pregnancy loss were also found to be not statistically significantly different between the groups. In contrast, more clinic visits and blood samplings for cycle monitoring were required in the NC-FET group (4.05 ± 1.39) compared with the modified NC-FET group (3.03 ± 1.16, P = <0.001), while the number of ultrasound scans performed were comparable (1.70 ± 0.88 in group A versus 1.62 ± 1.04 in group B). The additional PP analysis was in line with the ITT results: CPR in group A was 36.4% versus 38.1% in group B [RR 1.05, 95% CI (0.70;1.56), P = 0.82].

LIMITATIONS, REASONS FOR CAUTION

The results are limited by the high drop-out rate for the PP analysis in the modified NC-FET group as more than one-third of the subjects allocated to this group ovulated spontaneously before ovulation triggering. Nonetheless, this issue is inherent to routine clinical practice and is an important observation of an event that can only be avoided by performing a very extensive monitoring that limits the practical advantages associated with modified NC-FET. Furthermore, although this is the largest randomized controlled trial (RCT) investigating this specific research question so far, a higher sample size would allow smaller differences in clinical outcome to be detected, since currently they may be left undetected.

WIDER IMPLICATIONS OF THE FINDINGS

This RCT adds new high-quality evidence to the existing controversial literature concerning the performance of NC-FET versus modified NC-FET. Based on our results showing no statistically significant differences in clinical outcomes between the protocols, the treatment choice may be made according to the patient's and treating physician's preferences. However, the modified NC-FET strategy reduces the need for hormonal monitoring and may therefore be considered a more patient-friendly and potentially cost-effective approach.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was available for this study. None of the authors have a conflict of interest to declare with regard to this study.

TRIAL REGISTRATION NUMBER

NCT02145819.

TRIAL REGISTRATION DATE

8 January 2014.

DATE OF FIRST PATIENT’S ENROLMENT

21 January 2014.

Follicular-phase endometrial scratching: a truncated randomized controlled trial

STUDY QUESTION

Does intentional endometrial injury (scratching) during the follicular phase of ovarian stimulation (OS) increase the clinical pregnancy rate (CPR) in ART?

SUMMARY ANSWER

CPR did not vary between the endometrial injury and the control group, but the trial was underpowered due to early termination because of a higher clinical miscarriage rate observed in the endometrial injury arm after a prespecified interim analysis.

WHAT IS KNOWN ALREADY

Intentional endometrial injury has been put forward as an inexpensive clinical tool capable of enhancing endometrial receptivity. However, despite its widespread use, the benefit of endometrial scratching remains controversial, with several recent randomized controlled trials (RCTs) being unable to confirm its added value. So far, most research has focused on endometrial scratching during the luteal phase of the cycle preceding the one with embryo transfer (ET), while only a few studies investigated in-cycle injury during the follicular phase of OS. Also, the persistence of a scratch effect in subsequent treatment cycles remains unclear and possible harms have been insufficiently studied.

STUDY DESIGN, SIZE, DURATION

This RCT was performed in a tertiary hospital setting between 3 April 2014 and 8 October 2017. A total of 200 women (100 per study arm) undergoing IVF/ICSI in a GnRH antagonist suppressed cycle followed by fresh ET were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were randomized with a 1:1 allocation ratio to either undergo a pipelle endometrial biopsy between Days 6 and 8 of OS or to be in the control group.The primary outcome was CPR. Secondary outcomes included biochemical pregnancy rate, live birth rate (LBR), early pregnancy loss (biochemical pregnancy losses and clinical miscarriages), excessive procedure pain/bleeding and cumulative reproductive outcomes within 6 months of the study cycle.

MAIN RESULTS AND THE ROLE OF CHANCE

The RCT was stopped prematurely by the trial team after the second prespecified interim analysis raised safety concerns, namely a higher clinical miscarriage rate in the intervention group. The intention-to-treat CPR was similar between the biopsy and the control arm (respectively, 44 versus 40%, P = 0.61, risk difference = 3.6 with 95% confidence interval = -10.1;17.3), as was the LBR (respectively, 32 versus 36%, P = 0.52). The incidence of a biochemical pregnancy loss was comparable between both groups (10% in the intervention group versus 15% in the control, P = 0.49), but clinical miscarriages occurred significantly more frequent in the biopsy group (25% versus 8%, P = 0.032). In the intervention group, 3% of the patients experienced excessive procedure pain and 5% bleeding. The cumulative LBR taking into account all conceptions (spontaneous or following ART) within 6 months of randomization was not significantly different between the biopsy and the control group (54% versus 60%, respectively, P = 0.43).

LIMITATIONS, REASONS FOR CAUTION

The trial was stopped prematurely due to safety concerns after the inclusion of 200 of the required 360 patients. Not reaching the predefined sample size implies that definite conclusions on the outcome parameters cannot be drawn. Furthermore, the pragmatic design of the study may have limited the detection of specific subgroups of women who may benefit from endometrial scratching.

WIDER IMPLICATIONS OF THE FINDINGS

Intentional endometrial injury during the follicular phase of OS warrants further attention in future research, as it may be harmful. These findings should be taken in consideration together with the growing evidence from other RCTs that scratching may not be beneficial.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by 'Fonds Wetenschappelijk Onderzoek' (FWO, Flanders, Belgium, 11M9415N, 1524417N). None of the authors have a conflict of interest to declare with regard to this study.

Predicting suboptimal oocyte yield following GnRH agonist trigger by measuring serum LH at the start of ovarian stimulation

STUDY QUESTION

Are the LH levels at the start of ovarian stimulation predictive of suboptimal oocyte yield from GnRH agonist triggering in GnRH antagonist down-regulated cycles?

SUMMARY ANSWER

LH levels at the start of ovarian stimulation are an independent predictor of suboptimal oocyte yield following a GnRH agonist trigger.

WHAT IS KNOWN ALREADY

A GnRH agonist ovulation trigger may result in an inadequate oocyte yield in a small subset of patients. This failure can range from empty follicle syndrome to the retrieval of much fewer oocytes than expected. Suboptimal response to a GnRH agonist trigger has been defined as the presence of circulating LH levels <15 IU/l 12 h after triggering. It has been shown that patients with immeasurable LH levels on trigger day have an up to 25% risk of suboptimal response.

STUDY DESIGN, SIZE, DURATION

In this retrospective cohort study, all patients (n = 3334) who received GnRH agonist triggering (using Triptoreline 0.2 mg) for final oocyte maturation undergoing a GnRH antagonist cycle in our centre from 2011 to 2017 were included. The primary outcome of the study was oocyte yield, defined as the ratio between the total number of collected oocytes and the number of follicles with a mean diameter >10 mm prior to GnRH agonist trigger.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The endocrine profile of all patients was studied at initiation as well as at the end of ovarian stimulation. In order to evaluate whether LH levels, not only at the end but also at the start, of ovarian stimulation predicted oocyte yield, we performed multivariable regression analysis adjusting for the following confounding factors: female age, body mass index, oral contraceptives before treatment, basal and trigger day estradiol levels, starting FSH levels, use of highly purified human menopausal gonadotrophin and total gonadotropin dose. Suboptimal response to GnRH agonist trigger was defined as <10th percentile of oocyte yield.

MAIN RESULTS AND THE ROLE OF CHANCE

The average age was 31.9 years, and the mean oocyte yield was 89%. The suboptimal response to GnRH agonist trigger cut-off (<10th percentile) was 45%, which was exhibited by 340 patients. Following confounder adjustment, multivariable regression analysis showed that LH levels at the initiation of ovarian stimulation remained an independent predictor of suboptimal response even in the multivariable model (adjusted OR 0.920, 95% CI 0.871-0.971). Patients with immeasurable LH levels at the start of stimulation (<0.1 IU/l) had a 45.2% risk of suboptimal response, while the risk decreased with increasing basal LH levels; baseline circulating LH <0.5 IU/L, <2 IU/L and <5 IU/L were associated with a 39.1%, 25.2% and 13.6% risk, respectively.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of the study is its retrospective design.

WIDER IMPLICATIONS OF THE FINDINGS

This is the largest study of GnRH agonist trigger cycles only, since most of the previous research on the predictive value of basal LH levels was performed in dual trigger cycles. LH values should be measured prior to start of ovarian stimulation. In cases where they are immeasurable, suboptimal response to GnRH agonist trigger can be anticipated, and an individualized approach is warranted.

STUDY FUNDING/COMPETING INTEREST(S)

There was no funding and no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.

Single and double embryo transfer provide similar live birth rates in frozen cycles

Research question: Do live birth rates (LBRs) differ in frozen cycles of women who received single versus double embryo transfer?Design: Retrospective cohort study including women who underwent their first frozen embryo transfer (FET) in a tertiary referral University Hospital between 2009-2014.Results: 3601 patients were included in the analysis with 1936 (53.8%) having a single embryo transfer (SET) and 1665 (46.2%) having a double embryo transfer (DET). Overall, 657/3601 (18.24%) had a live birth. LBR were similar between SET and DET either for cleavage [100/757 (13.1%) versus 153/1032 (14.8%), p = .33] or blastocyst stage FET [256/1179 (21.7%) versus 148/633 (23.4%), p = .4). Ongoing pregnancy rates were comparable between DET and SET [316/1665 (18.9%) versus 359/1936 (18.5%)]. Multiple delivery rates were significantly higher in women with DET compared to SET [53/316 (16.7%) versus 7/359 (1.9%), p < .001]. Multivariate logistic regression analysis allowing adjustment for relevant confounders showed that the number of embryos transferred in the frozen cycle was not related to LBR.Conclusions: This is the largest study providing evidence that both SET and DET may result in similar LBR, albeit multiple pregnancy rates are significantly lower in case of SET. Therefore, SET should be the main strategy in women undergoing FET.

Do we need to measure progesterone in oocyte donation cycles? A retrospective analysis evaluating cumulative live birth rates and embryo quality

STUDY QUESTION

Does late follicular-phase elevated serum progesterone (LFEP) during ovarian stimulation for oocyte donation have an impact on embryo quality (EQ) and cumulative live birth rate (CLBR)?

SUMMARY ANSWER

LFEP does not have an influence on EQ nor CLBR in oocyte donation cycles.

WHAT IS KNOWN ALREADY

Ovarian stimulation promotes the production of progesterone (P) which, when elevated during the follicular phase, has been demonstrated to have a deleterious effect in autologous fresh IVF outcomes. While there is robust evidence that this elevation results in impaired endometrial receptivity, the impact on EQ remains a matter of debate. The oocyte donation model is an excellent tool to assess the effects of LFEP on EQ from those on endometrium receptivity separately. Previous studies in oocyte donation cycles investigating the influence of elevated P on pregnancy outcomes in oocyte recipients showed conflicting results.

STUDY DESIGN, SIZE, DURATION

This is a retrospective analysis including all GnRH antagonist down-regulated cycles for fresh oocyte donation taking place in a tertiary referral university hospital between 2010 and 2017. A total of 397 fresh donor-recipient cycles were included. Each donor was included only once in the analysis and could be associated to a single recipient.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The sample was stratified according to serum P levels of ≤1.5 and &gt;1.5 ng/mL on the day of ovulation triggering. The primary endpoint of the study was the top-quality embryo rate on Day 3, and the secondary outcome measure was CLBR defined as a live-born delivery beyond 24 weeks.

MAIN RESULTS AND THE ROLE OF CHANCE

Three hundred ninety-seven fresh oocyte donation cycles were included in the analysis, of which 314 (79%) had a serum P ≤ 1.5 ng/mL and 83 (20.9%) had a serum P &gt; 1.5 ng/mL. The average age of the oocyte donors was 31.4 ± 4.7 and 29.9 ± 4.5 years, respectively, for normal and elevated P (P = 0.017). The mean number of oocytes retrieved was significantly higher in the elevated P group with 16.6 ± 10.6 vs 11.5 ± 6.9 in the P ≤ 1.5 group (P &lt; 0.001).

In parallel, the total number of embryos on Day 3, as well as the number of good-quality embryos at this stage, was significantly higher in the elevated P group (6.6 ± 5.6 vs 4.15 ± 3.5 and 8.7 ± 6.3 vs 6.1 ± 4.4; respectively, P &lt; 0.001). However, maturation and fertilization rates did not vary significantly between the two study groups and neither did the top- and good-quality embryo rate and the embryo utilization rate, all evaluated on Day 3 (P = 0.384, P = 0.405 and P = 0.645, respectively). A multivariable regression analysis accounting for P groups, age of the donor, number of retrieved oocytes and top-quality embryo rate as potential confounders showed that LFEP negatively influenced neither the top-quality embryo rate nor the CLBR.

LIMITATIONS, REASONS FOR CAUTION

This is an observational study based on a retrospective data analysis. Better extrapolation of the results could be validated by performing a prospective trial. Furthermore, this study was focused on oocyte donation cycles and hence the results cannot be generalized to the entire infertile population.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study providing evidence that LFEP does not influence CLBR and is adding strong evidence to the existing literature that LFEP does not harm EQ in oocyte donation programs.

STUDY FUNDING/COMPETING INTERESTS

Not applicable.

Influence of adenomyosis on pregnancy and perinatal outcomes in women with endometriosis

OBJECTIVES

Several studies have investigated the correlation between endometriosis and adverse pregnancy and perinatal outcomes. However, the role of adenomyosis as a risk factor for adverse perinatal outcome in women with endometriosis has yet to be established. The aim of this study was to explore if fetal and maternal outcomes, in particular the incidence of a small-for-gestational-age (SGA) infant, are different in pregnant women with endometriosis only from in those with the concomitant presence of diffuse or focal adenomyosis.

METHODS

This was a retrospective analysis of data collected prospectively during a 3-year period. We included 206 pregnant women with endometriosis: 148 (71.8%) with endometriosis only, 38 (18.4%) with focal adenomyosis and 20 (9.7%) with diffuse adenomyosis. Adenomyosis was diagnosed using ultrasonography and was classified as focal or diffuse. The study included patients who conceived spontaneously or by an assisted reproductive technique. Demographics, ultrasound variables and outcome were compared between women with endometriosis only and those with diffuse and those with focal adenomyosis. Logistic regression analysis was performed to assess the association of variables with SGA at birth in women with diffuse and those with focal adenomyosis.

RESULTS

The three groups were similar in demographic characteristics (age, body mass index, mode of conception). Patients with diffuse adenomyosis compared with those with endometriosis only had significantly lower pregnancy-associated plasma protein A (0.61 vs 0.88 multiple of the median, P < 0.001), higher mean uterine artery pulsatility index in the first (2.23 vs 1.67, P < 0.001) and second (1.30 vs 0.94, P < 0.001) trimesters of pregnancy, and higher incidence of SGA (40% vs 10.8%, P < 0.001). No statistically significant differences were found in patients with focal adenomyosis compared with those with endometriosis only. Logistic regression analysis demonstrated that diffuse adenomyosis (odds ratio = 3.744; 95% CI, 1.158-12.099; P = 0.027) was the only independent risk factor for SGA.

CONCLUSIONS

The presence of diffuse adenomyosis in pregnant women with endometriosis is strongly associated with delivery of a SGA infant. Women with diffuse adenomyosis should be treated as being at high risk of placental dysfunction, and these pregnancies might therefore need closer monitoring. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Frozen embryo transfer: a review on the optimal endometrial preparation and timing

STUDY QUESTION

What is the optimal endometrial preparation protocol for a frozen embryo transfer (FET)?

SUMMARY ANSWER

Although the optimal endometrial preparation protocol for FET needs further research and is yet to be determined, we propose a standardized timing strategy based on the current available evidence which could assist in the harmonization and comparability of clinic practice and future trials.

WHAT IS KNOWN ALREADY

Amid a continuous increase in the number of FET cycles, determining the optimal endometrial preparation protocol has become paramount to maximize ART success. In current daily practice, different FET preparation methods and timing strategies are used.

STUDY DESIGN, SIZE, DURATION

This is a review of the current literature on FET preparation methods, with special attention to the timing of the embryo transfer.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Literature on the topic was retrieved in PubMed and references from relevant articles were investigated until June 2017.

MAIN RESULTS AND THE ROLE OF CHANCE

The number of high quality randomized controlled trials (RCTs) is scarce and, hence, the evidence for the best protocol for FET is poor. Future research should compare both the pregnancy and neonatal outcomes between HRT and true natural cycle (NC) FET. In terms of embryo transfer timing, we propose to start progesterone intake on the theoretical day of oocyte retrieval in HRT and to perform blastocyst transfer at hCG + 7 or LH + 6 in modified or true NC, respectively.

LIMITATIONS REASONS FOR CAUTION

As only a few high quality RCTs on the optimal preparation for FET are available in the existing literature, no definitive conclusion for benefit of one protocol over the other can be drawn so far.

WIDER IMPLICATIONS OF THE FINDINGS

Caution when using HRT for FET is warranted since the rate of early pregnancy loss is alarmingly high in some reports.

STUDY FUNDING/COMPETING INTEREST(S)

S.M. is funded by the Research Fund of Flanders (FWO). H.T. and C.B. report grants from Merck, Goodlife, Besins and Abbott during the conduct of the study.

TRIAL REGISTRATION NUMBER

Not applicable.

[Clinical usefulness of Beta2microglobulin in patients with Primary Sjögren Syndrome]

The extraglandular manifestations and lymphoproliferative disorders are complications in pSS. There are few serological markers that they are useful in these conditions.

OBJETIVES

to evaluate the usefulness of the β2microglobulin level in patients with pSS and its relation to extra glands manifestations , lymphoproliferative disorders and the presence of Rheumatoid factor (RF), serum immunoglobulins (Igs), and C3 and C4 levels.

MATERIAL AND METHODS

we retrospectively studied patients with pSS , OAD and healthy controls . Ig G, Ig A and Ig M levels, serum complement C3 and C4 and RF were performed by immunoturbidimetry, and β2microglobulin protein by the ELISA technique in all patients.

RESULTS

19 patients with pSS (Group SSp), 28 patients with other autoimme diseases diferent from pSS (Group PAD) and 24 healthy controls (Group C).There was an signifcant increase of β2m values in Groups SS and OAD vs Group C (6.19 mg/dl vs. 2.53 mg/dl p<0.001) and (4.38 mg/dl vs. 2.53 mg/dl p<0.01). On the other hand, mean β2m levels in Group SS were higher than in Group OAD (6.19 vs. 4.38 mg/dl p<0.01).There was not a relationship between β2m level and Ig G, A , M ,complement levels and the presence of RF.

CONCLUSION

β2m can discriminate patients with pSS from those with other autoimmune diseases and healthy subjects. Increased β2m level in pattients with pSS could reflect hyperactivation of B cells and it could be a potential marker associated with extraglandular manifestations and cell lymphoproliferative disorders.

Antibodies and PMBC from EIAV infected carrier horses recognize gp45 and p26 synthetic peptides

Equine infectious anemia virus (EIAV) is a lentivirus causing a persistent infection in horses characterized by recurrent febrile episodes and high levels of viremia associated with a novel antigenic strain of the virus. The virus contains two envelope glycoproteins, gp90 and gp45, and four internal proteins, p26, p15, p11 and p9. Considering that the most infected horses are able to restrict EIAV replication to very low levels and that gp45 and p26 contain highly conserved epitopes among lentiviruses, it would be necessary to identify those conserved epitopes stimulating cellular and humoral responses. The aims of this study were to determine if the synthetic peptides identified as gp45 (aa 523-547) and p26 (aa 318-346) representing two highly conserved and immunodominant regions of EIA virus are recognized by PBMC and antibodies to EIAV adult mixed-breed naturally infected carrier horses, and if these peptides are able to induce immune responses in mice. Antibodies from 100% of carrier horses, evaluated by ELISA, recognized both peptides; PBMC from 80% of carrier horses, evaluated by lymphoproliferation assay, recognized, at least, one peptide. Furthermore, immunization with 100 microg of each peptide elicited humoral and cellular responses in BALB/c mice, antibodies appeared at 48 or 63 days of immunization with gp45 or p26, respectively. Although the kinetics of gp45- and p26-specific antibody responses were similar, percentage of positivity was higher for gp45. The lymphoproliferation assay, evaluated by BrdU uptake, was higher in mice immunized with gp45 or p26 than in the control group (P<0.05). Based on our findings, we consider that both peptides could be included in an effective vaccine design to induce long-term immunological memory.

Participation of RANTES and T-Cell Apoptosis in Human Renal Allograft

The aim of this study was to evaluate the serum RANTES (Regulated upon Activation of Normal T cell Expressed and Secreted) levels and the expression of CCR5, as well as the percentage of apoptotic cells, in peripheral T lymphocytes from renal transplanted patients with acute rejection (AR), chronic rejection (CR) or stable evolution (SE). RANTES serum levels were determined by enzyme-linked immunoadsorbent assay and CCR5 expression, as well as the percentage of apoptotic lymphocytes, on a FACScan flow cytometer. After staining with different antibodies, the cells were subjected to three-colour flow cytometric analysis. Data analysis was performed using winmdi 2.5 software. The serum RANTES level and percentages of CCR5/CD4 and CCR5/CD8 T lymphocytes in CR, AR and SE were lower than that in the control group (P <0.05). The level of CD4 and CD8 T lymphocytes in early apoptosis was higher in AR patients than in CR, SE or C groups (P <0.05). In the case of late apoptosis, the percentage of apoptotic/necrotic cells was higher in the CR than AR, SE or C groups (P <0.05). The RANTES serum levels and the percentage of peripheral CCR5 T lymphocytes would not indicate the renal allograft state. The increase of early apoptotic T lymphocytes could be a marker of AR process and could also indicate the initial step in reducing the cytotoxic T lymphocytes, thus favouring the graft evolution.

A Dc- phenotype encoded by an RHCE-D(5-7/8)-CE hybrid allele

BACKGROUND AND OBJECTIVES

The Rh system is genetically controlled by the homologous RHD and RHCE genes that encode the RhD and RhCcEe polypeptides, respectively. Deletions, point mutations and rearrangements between both genes are responsible for the great polymorphism of this system. The aim of this work was to analyse the genetic basis of a Dc- phenotype.

MATERIALS AND METHODS

DNA samples from the Dc- propositus and family members were obtained from peripheral blood. RHCE intron 4-exon 5 and RH exons 4, 5, 6 and 7 were analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Exon 9 was studied by PCR-sequence-specific primers (SSP). The RH locus was further analysed by using a PCR designed for a hybrid allele.

RESULTS

No RHCE-specific fragments were found when analysing exons 5, 6 and 7 of the RH locus from the propositus' DNA, while exons 4 and 9 of both RH genes were present.

CONCLUSIONS

The results obtained indicated that the Dc- phenotype is encoded by a novel RHCE-D(5-7/8)-CE hybrid allele.

Gammadelta T cells and interleukin-6 levels could provide information regarding the progression of human renal allograft

We have determined the percentage of alphabeta and gammadelta T cells by flow cytometry as well as serum interleukin-6 (IL-6) and soluble interleukin-6 receptor (sIL-6R) levels by enzyme-linked immunosorbent assay in kidney allograft recipients with acute, chronic or stable graft evolution. The percentage of CD4 and CD8 T cells in transplanted patients was lower than in the control group (P < 0.001) with the exception of CD8 gammadelta T cells from patients with stable evolution (P > 0.05). The serum levels of IL-6 and sIL-6R in acute and chronic rejection were higher than in the controls (P < 0.05). No differences in IL-6 levels were observed between the stable evolution and the control groups (P > 0.05). The levels of sIL-6R were higher in stable evolution patients than in the controls (P < 0.05) and no differences were observed between the chronic and stable evolution patients (P > 0.05). IL-6 decreased in patients with a favourable evolution, increased in those with an increased renal dysfunction and was maintained when the renal dysfunction was not modified. These results suggest that gammadelta T cells could participate in renal allograft maintenance and that IL-6 but not sIL-6R serum levels may provide a prognostic marker for measuring the evolution of kidney allograft.

Study of phagocytosis of senescent erythrocytes in young and elderly individuals

There is a decrease in the percentage contribution of a heavy density fraction of red blood cells to whole blood with increasing age. The aim of this study was to investigate in the young and elderly the interaction between monocytes and different erythrocyte suspensions: senescent red blood cells, erythrocytes stored with or without serum, and desialylated red blood cells. The results obtained with senescent red blood cells and erythrocytes stored with serum show the involvement of autologous IgG in the selective removal of erythrocytes. These values were higher in elderly individuals, indicating that this process increases with age. Our observation suggest that desialylation is not involved in the increased removal of erythrocytes observed in elderly individuals.

Early detection of RhD status in pregnancies at risk of hemolytic disease of the newborn

The aim of this work was to investigate the presence of the RHD gene in fetal cells obtained from amniotic fluid. We studied 65 samples of amniotic fluid, 11 from RhD-negative mothers sensitized with anti-D alloantibodies. The fetal origin of the DNA was confirmed with the analysis of 1 VNTR locus and 3 STR loci in DNA samples from amniotic fluid and maternal blood. The RHD genotyping was performed in non-contaminated samples (n=62) using a multiplex polymerase chain reaction strategy that yields three amplification products from RhD-positive phenotypes (intron 4 of both RHCE and RHD genes and exon 10 of the RHD gene) and I DNA fragment from RhD-negative phenotypes (intron 4 of the RHCE gene). We genotyped 54 RhD-positive fetuses (8 from RhD-negative sensitized mothers) and 8 RhD-negative fetuses (3 from RhD-negative sensitized mothers). The fetal DNA genotyping allows the diagnosis, from a single amniocentesis, of fetuses at real risk of hemolytic disease of the newborn. When the fetus is determined to be RhD-negative invasive procedures can be avoided.

Senescent erythrocytes: factors affecting the aging of red blood cells

Human red blood cells (RBC) have a well-defined lifespan of 120 days affected by many cellular parameters. The aim of the present study was to investigate through a functional assay the effect of some factors in the interaction of erythrocytes with monocytes: heat rigidification, equilibration at different pH and desialyzation. We also studied the interaction between stored RBC and peripheral blood monocytes with this functional erythrophagocytosis assay. Blood samples from 30 volunteer donors were investigated. 1) Senescent (Se) and Young (Y) RBC were obtained by differential centrifugation. 2) Erythrocyte suspensions: Aliquots of each sample were subjected to the following treatments: a) Rigidification by heat (RRBC), b) Equilibration at different pH (5.34, 6.30, 7.33, 9.20) and c) Desialyzation with neuraminidase and trypsin. The functional assay was performed incubating monocytes obtained by glass adherence with these suspensions of RBC. Whole blood samples (n = 20) were stored during different periods of time (0, 7, 14, 21, 28, 35 and 42 days). The erythrophagocytosis assay was performed during six weeks incubating isologous monocytes with RBC from every unit. Negative and positive controls were performed using non sensitized (NSRBC) and sensitized with IgG anti-RhD (SRBC) red cells. The percentage of active monocytes (AM) obtained were: 1) YRBC: 2.8 +/- 0.9 and SeRBC: 17.5 +/- 2.1; 2a) RRBC: 3.0 +/- 0.9; 2b) 10.9 +/- 0.9, 15.5 +/- 0.8, 3.1 +/- 1.0, 4.0 +/- 1.1; 2c) 11.1 +/- 1.4 and 3.9 +/- 1.0; SRBC 32.1 +/- 1.7 and NSRBC: 2.8 +/- 1.5. The % of AM with SeRBC was higher (p < 0.001) than those obtained with NSRBC. The data of AM with RRBC were significantly lower (p < 0.001) than those obtained with SeRBC and SBRC, indicatingthat heat rigidification of RBC does not increase phagocytosis by monocytes. The values of AM obtained from the suspensions of erythrocytes equilibrated at different pH indicate that the acidification of RBC increases the interaction with monocytes. The % AM with neuraminidase treated RBC was higher than those observed with YRBC and NSRBC (p < 0.001). No modifications were observed with trypsin treated RBC. These results suggest that the loss of sialic acid may be involved in the physiological phagocytosis. The values of AM of stored whole blood were: 2.3 +/- 1.3, 2.7 +/- 1.3, 4.4 +/- 1.6, 6.7 +/- 1.2, 9.6 +/- 1.0, 11.7 +/- 0.8 and 13.0 +/- 1.2. The results showed a significant increase in the % of AM as a function of the preservation time from 2,3 +/- 1,3 for the first day to 13,0 +/- 1,2 for the 42nd day (p < 0.001). The data obtained in this ex vivo model show a significant increase (p<0.001) in the phagocytosis of RBC equilibrated at low pH, desialinized (greater than 80%) with neuraminidase and stored for over 28 days. These factors would be involved in erythrocyte removal via phagocytosis during tissular homeostasis.

Erythrophagocytosis assay in patients with autoimmune hemolytic anemia

The aim of this paper is to evaluate the erythrophagocytosis assay (EA) in patients with autoimmune hemolytic anemia (AIHA). Direct antiglobulin test (DAT), indirect antiglobulin test (IAT) and EA were performed in blood samples from 46 patients with presumed AIHA. The EA was carried out incubating patients' erythrocytes and peripheral blood monocytes. A total of 200 monocytes were analysed to determine the percentage of active phagocytic cells (% APC). In 9 of these patients the applied treatment was evaluated by DAT, IAT and EA. In 14 transfusion requirements, the compatibility tests and EA were performed. For EA, patients' monocytes were incubated with erythrocytes from previously selected units sensitized with patients' sera. The % of APC was 32.1 +/- 1.7 in 35 patients with positive DAT and 17.8 +/- 1.3 in 11 patients with negative DAT. This last value was significantly higher than that with negative controls (3.7 +/- 0.3)(p < or = 0.01). As regards the applied treatment, patients with a successful response (n = 6) showed a significant decrease in the initial % APC (31.8 +/- 1.6 to 15.3 +/- 2.4; p < or = 0.05) while DAT and IAT remained positive. In those patients who required blood transfusion the compatibility tests were positive with all the units to be transfused, whereas the % APC varied for each one. Blood units were selected according to the lower % APC.

[Rh system genotyping in amniotic fluid]

The aim of this work was to determine the presence of the RHD gene in fetal cells obtained from amniotic fluid (AF). We studied 65 samples of AF, 11 from RhD- mothers sensitized with anti-D. The fetal origin of the DNA was confirmed with the analysis of 1 VNTR locus and 3 STR loci in DNA samples from AF and maternal blood. The RHD genotyping was performed in non contaminated samples (n = 62) using a multiplex PCR strategy that yields 3 amplification products from RhD+ phenotypes and 1 DNA fragment from RhD- phenotypes. We genotyped 54 RhD+ fetuses (8 from RhD- sensitized mothers) and 8 RhD- fetuses (3 from RhD- sensitized mothers). Fetal DNA genotyping allows the diagnosis, from a single amniocentesis, of fetuses at real risk of hemolytic disease of the newborn. When the fetus is determined to be RhD- all invasive procedures can be avoided.

Molecular determination of RhD phenotype by DNA typing: clinical applications

Rhesus D (RhD) typing is performed by agglutination methods; however, in clinical situations where these techniques cannot be performed, RhD DNA typing is an alternative approach. The Rh antigens are encoded by the RHD and RHCE genes. In RhD-negative individuals the RHD gene is absent or grossly deleted, but variations in the arrangement of the RH locus in different populations are emerging. The aim of this study was to analyse the gross organization of the RH genes in our population using a previously described multiplex polymerase chain reaction (PCR) method with some modifications. We studied 253 DNA samples from Argentinian blood donors, 15 samples with a reduced expression of the D antigen and 1 Dc- phenotype. We evaluated the clinical utility of this method to ascertain the RhD antigen in 10 patients with warm-type autoimmune haemolytic anaemia (AIHA) and 14 samples of amniotic fluids. All Rh phenotypes were properly characterized and no discrepancies with serological typing were found. Analyses performed in the Dc- phenotype suggest the presence of a hybrid RHCE-RHD gene. DNA typing confirmed the RhD-negative type of one AIHA sample in which serological tests were inconclusive. Foetal DNA typing correctly indicated the RhD in every foetus. VNTR (variable number of tandem repeats) and STR (short tandem repeats) analysis detected maternal contamination in two amniocentesis samples and confirmed the foetal origin of 12. This multiplex PCR strategy is suitable for RhD determination in clinical situations in which serological typing cannot be accomplished with its usual ease.