Xiaoying Zheng

Single-cell RNA-Seq profiling of human preimplantation embryos and embryonic stem cells

Measuring gene expression in individual cells is crucial for understanding the gene regulatory network controlling human embryonic development. Here we apply single-cell RNA sequencing (RNA-Seq) analysis to 124 individual cells from human preimplantation embryos and human embryonic stem cells (hESCs) at different passages. The number of maternally expressed genes detected in our data set is 22,687, including 8,701 long noncoding RNAs (lncRNAs), which represents a significant increase from 9,735 maternal genes detected previously by cDNA microarray. We discovered 2,733 novel lncRNAs, many of which are expressed in specific developmental stages. To address the long-standing question whether gene expression signatures of human epiblast (EPI) and in vitro hESCs are the same, we found that EPI cells and primary hESC outgrowth have dramatically different transcriptomes, with 1,498 genes showing differential expression between them. This work provides a comprehensive framework of the transcriptome landscapes of human early embryos and hESCs.

MicroRNA array and microarray evaluation of endometrial receptivity in patients with high serum progesterone levels on the day of hCG administration

BackgroundTo determine the effect of higher progesterone (P) level on endometrial receptivity.MethodsThis was a prospective analysis conducted in the Reproductive Medical Center of Peking University Third Hospital. All patients received IVF treatment and canceled embryo transfer in the same cycle and were divided into group 1 (normal P; 7 patients) and group 2 (elevated P; 12 patients). Endometrial biopsies were performed 6 days after oocyte retrieval. The global miRNA and mRNA gene expressions in endometrial biopsies were investigated with a V4.0 miRNA probe and 22 K Human Genome Array. Fold ratios were derived to compare gene regulation between the groups. Spp1 and Ang gene expression was selected to verify the array results by RT-PCR and the protein expression of osteopontin and VEGF was determined using an immunohistochemical method.ResultsThere were 4 miRNA (all down-regulated) and 22 mRNA (13 up-regulated and 9 down-regulated) exhibiting differential expression between the groups on the microRNA and microarray chips. miRNA-451, Spp1, and Ang expression in RT-PCR verified the array results. Osteopontin and VEGF were also shown to have positive expression in the endometrium.ConclusionsData from microRNA and microarray analysis suggests dissimilar endometrial receptivity in patients with high P levels on the day of hCG, and elevated osteopontin and decreased VEGF had poor pregnancy rates.

Synchronization between embryo development and endometrium is a contributing factor for rescue ICSI outcome

Recent evidence shows that the outcome of rescue intracytoplasmic sperm injection (ICSI) is unsatisfactory on account of a poor clinical pregnancy rate. These outcomes may be due to either the in-vitro ageing of cultured oocytes before ICSI or the asynchrony between the embryo developmental stage and the endometrial secretory pattern. To address the latter issue, this study performed a retrospective analysis of 534 fresh cycles after rescue ICSI and 64 frozen-thawed cycles in subsequent treatment. Rescue ICSI cycles were divided into three groups: group I included 469 fresh embryo-transfer (FET) cycles; group II included 74 FET cycles in which supernumerary good-quality embryos were also cryopreserved; and group III included 64 frozen-thawed transfer cycles. Group III was considered to have achieved better synchronization than group II. As a result, significantly higher clinical pregnancy (29.69%, 19/64 versus 10.81%, 8/74) and implantation (13.33%, 22/165 versus 5.13%, 8/156) rates were achieved in group III compared with group II (both P<0.05). Therefore, synchronization of embryo development with the endometrium is considered a contributing factor for rescue ICSI outcome. It is recommended that embryos derived from rescue ICSI cycles should be cryopreserved and subsequently used in frozen-thawed cycles. Intracytoplasmic sperm injection (ICSI) of unfertilized 1-day-old oocytes, called rescue ICSI, has frequently been performed in some infertility centres, when fertilization failure sometimes occurs in conventional IVF cycles. Recent studies showed that the outcome of rescue ICSI was unsatisfactory due to poor clinical pregnancy rates. One reason could be asynchrony between the embryo developmental stage and the endometrial secretory pattern. To address this issue, we performed a retrospective analysis of 534 fresh cycles after rescue ICSI (from January 2006 to January 2011) and 64 frozen-thawed transfer cycles in subsequent treatment (from January 2006 to May 2011) in our infertility centre. In this study, rescue ICSI cycles were divided into three groups. As there was no significant difference in womens age (31.22 ± 3.38 versus 31.11 ± 3.27 years) between groups II and III, we principally compared these two groups. Group II included 74 fresh embryo transfer cycles, in which supernumerary good-quality embryos were cryopreserved, and group III included 64 frozen-thawed transfer cycles. Group III was considered to have better synchronization than group II. As a result, significantly higher clinical pregnancy (29.69% versus 10.81%) and implantation (13.33% versus 5.13%) rates were achieved in group III compared with group II. Therefore, endometrial synchronization is considered a contributing factor for rescue ICSI outcome and embryos derived from rescue ICSI cycles should be cryopreserved and subsequently used in frozen-thawed cycles.

Neonatal outcomes after the transfer of vitrified blastocysts: closed versus open vitrification system

BackgroundIncreasing evidence indicates that closed vitrification has been successfully used in the cryopreservation of human oocytes and embryos. Little information is available regarding the neonatal outcome of closed blastocysts vitrification. The aim of this study was to evaluate the effectiveness and safety of blastocyst vitrification using a high-security closed vitrification system compared with an open vitrification system.MethodsA total of 332 vitrified-warmed blastocyst transfer cycles between April 2010 and May 2012 were analyzed retrospectively. The post-thaw survival rate, implantation rate, clinical pregnancy rate, live birth rate, and neonatal outcome were recorded.ResultsThere were no significant differences between the open vitrification group and the close vitrification group regarding the post-thaw survival rate (98% versus 95.8%), clinical pregnancy rate (47.6% versus 42.2%), implantation rate (42.9% versus 35.6%), and live birth rate (39.8% versus 32.1%). In total, 332 warming cycles produced 131 healthy babies. There were no significant differences in the mean gestational age, the birth weight, and the birth length between the two groups. No adverse neonatal outcomes were observed in the children born after the transfer of closed vitrified blastocysts compared with the transfer of open vitrified blastocysts.ConclusionsThese data suggest that blastocyst vitrification using a closed vitrification device seems safe and effective with results comparable to those obtained through open vitrification.

Effect of hCG priming on embryonic development of immature oocytes collected from unstimulated women with polycystic ovarian syndrome

BackgroudThe effect of hCG priming on oocyte maturation and subsequently outcome in IVM cycles has remained a debated issue. A randomized controlled study was performed to investigate whether or not hCG priming prior to oocyte aspiration can improve the developmental competence of immature oocytes from unstimulated ovaries in women with polycystic ovarian syndrome (PCOS).MethodsEighty two patients with PCOS underwent IVM cycles. Each patient was randomly assigned to the hCG-primed (10,000 IU) or non-primed groups 36–38 hours before oocyte retrieval depending on the computerized random table. After the oocytes had in vitro matured, fertilization, culture and embryo transfer were performed.ResultsThe average number of cumulus-oocyte complexes (COCs) recovered was 13.80 and 14.35 in the hCG-primed and non-primed groups, respectively (p > 0.05). The maturation rate of COCs was significantly improved in the hCG-primed group (55.43% vs. 42.29%; p < 0.05). The fertilization and cleavage rates were comparable between the groups. The hCG-primed and non-primed groups did not differ with respect to the clinical pregnancy (37.50% vs. 50.00%), live birth (22.50% vs. 30.95%), and implantation rates (32.86% vs. 32.56%). The pregnancy losses was 6 (40.00%) of 15 clinical pregnancies in the hCG-primed group, and 8 (38.10%) of 21 clinical pregnancies in the non-primed group.ConclusionsWhile a significant improvement in the nuclear maturation rate of immature oocytes was observed in hCG-primed IVM cycles with PCOS patients, the use of hCG prior to oocyte retrieval did not improve the subsequent embryo developmental competence. The high rate of pregnancy loss in IVM cycles should receive more attention.

Effect of ABO blood type on ovarian reserve in Chinese women

OBJECTIVE To explore the effect of ABO blood type on ovarian reserve in Chinese women. DESIGN Retrospective analysis. SETTING University-affiliated IVF center. PATIENT(S) The retrospective analysis involved 35,479 women who underwent in vitro fertilization and embryo transfer (IVF-ET) cycles between 2006 and 2012. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) The association between ABO blood types and diminished ovarian reserve (DOR). RESULT(S) Among 35,479 Chinese women, 11,395 (32.12%) had blood type B, 10,583 (29.83%) had blood type O, 9,861 (27.79%) had blood type A, and 3,640 (10.26%) had blood type AB. There was a statistically significantly higher percentage of blood type O among those with follicle-stimulating hormone (FSH) levels ≤10 IU/L compared with those with FSH levels >10 IU/L. Conversely, among the women with DOR, there was statistically significantly higher percentage of those with blood types B and AB. Blood type A was not associated with DOR occurrence. Multivariate logistic regression analysis showed that blood type O was statistically significantly less often associated with DOR occurrence, whereas the B antigen (blood type B or AB) was statistically significantly associated with an increased risk of DOR. CONCLUSION(S) Our results have shown that there is an association between ABO blood type and DOR occurrence in Chinese women. Women with blood type O were statistically significantly less likely to have DOR, whereas those with B antigen (blood type B or AB) were statistically significantly more likely to have DOR. Blood type A was not associated with ovarian reserve.

Expression of bone morphogenetic protein-15 in human oocyte and cumulus granulosa cells primed with recombinant follicle-stimulating hormone followed by human chorionic gonadotropin

Bone morphogenetic protein-15 is expressed in oocytes and cumulus granulosa cells. It may play an important role in the hCG-induced oocyte final maturation and corpus luteum (CL) formation.

Influence of embryo culture medium on incidence of ectopic pregnancy in in vitro fertilization

OBJECTIVE To explore the effect of type of media used to culture embryos for IVF on the incidence of ectopic pregnancy (EP). DESIGN Retrospective analysis. SETTING University-affiliated IVF center. PATIENT(S) The retrospective analysis involved 23,481 women who underwent IVF-ET cycles between 2011 and 2013. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) There was an association between EP and the culture medium. RESULT(S) During 23,481 fresh transfer cycles, 364 patients were diagnosed with EP. The EP to clinical pregnancy rate was 3.01% in the G5 group, 3.89% in the G5 Plus group, and 4.04% in the Global group. The EP to clinical pregnancy rates were significantly higher in the G5 Plus and Global groups than in the G5 group. After adjusting for confounding factors, the incidence of EP was significantly associated with the G5 Plus and Global media. CONCLUSION(S) Our results showed that there is an association between incidence of EP and the culture medium. The rates of EP to clinical pregnancy were significantly higher in the G5 Plus and Global media than in the G5 medium.

Evaluation of syphilis serostatus on the safety of IVF treatment.

An increasing number of infertile syphilis-infected individuals have turned to assisted reproductive technology; however, the safety of syphilis carrier serostatus on IVF and embryo transfer outcomes has not been evaluated. Data from 482 patients who delivered singletons were analysed. In the retrospective study, the rate of IVF and intracytoplasmic sperm injection fertilization was 79.50% ± 17.57%/78.72% ± 16.66% in the Treponema pallidum particle agglutination assay negative (TPPA-negative) and rapid plasma reagin negative (RPR-negative) group, 76.12% ± 22.99%/74.05% ± 20.31% in the TPPA-positive and RPR-negative group, and 75.66% ± 21.72%/70.90% ± 16.11% in the TPPA-positive and RPR-positive group. The clinical pregnancy rate was 39.79% in the TPPA-negative and RPR-negative group, 46.30% in the TPPA-positive and RPR-negative group, and 36.59% in the TPPA-positive and RPR-positive group. No significant differences were found between the groups. The neonatal gestational age and mean birth weight were not significantly different between the TPPA-negative and TPPA-positive groups. Multiple linear regression analysis also showed no association between TPPA serostatus and newborn birth weight and gestational age. The present retrospective study showed that TPPA and RPR serostatus did not affect the outcomes of IVF and embryo transfer. Syphilis-infected individuals can undergo IVF and embryo transfer cycles after penicillin treatment.

Current perspectives on in vitro maturation and its effects on oocyte genetic and epigenetic profiles

In vitro maturation (IVM), the maturation in culture of immature oocytes, has been used in clinic for more than 20 years. Although IVM has the specific advantages of low cost and minor side effects over controlled ovarian stimulation, the prevalence of IVM is less than 1% of routine in vitro fertilization and embryo transfer techniques in many reproductive centers. In this review, we searched the MEDLINE database for all full texts and/or abstract articles published in English with content related to oocyte IVM mainly between 2000 and 2016. Many different aspects of the IVM method may influence oocyte potential, including priming, gonadotrophin, growth factors, and culture times. The culture conditions of IVM result in alterations in the oocyte or cumulus cell transcriptome that are not observed under in vivo culture conditions. Additionally, epigenetic modifications, such as DNA methylation or acetylation, are also different between in vitro and in vivo cultured oocytes. In sum, current IVM technique is still not popular and requires more systematic and intensive research to improve its effects and applications. This review will help point our problems, supply evidence or clues for future improving IVM technique, thus assist patients for fertility treatment or preservation as an additional option.