STUDY QUESTION: Is there an efficient and cost-effective detection platform for different genetic conditions about embryos? SUMMARY ANSWER: A multifunctional haplotyping-based preimplantation genetic testing platform was provided for detecting different genetic conditions. WHAT IS KNOWN ALREADY: Genetic disease and chromosomal rearrangement have been known to significantly impact fertility and development. Therefore, preimplantation genetic testing for aneuploidy (PGT-A), monogenic disorders (PGT-M) and structural rearrangements (PGT-SR), a part of ART, has been presented together to minimize the fetal genetic risk and increase pregnancy rate. For patients or their families who are suffering from chromosome abnormality, monogenic disease, unexplained repeated spontaneous abortion or implantation failure, after accepting genetic counseling, they may be suggested to accept detection from more than one PGT platforms about the embryos to avoid some genetic diseases. However, PGT platforms work through different workflows. The high costliness, lack of material and long-time operation of combined PGT platforms limit their application. STUDY DESIGN, SIZE, DURATION: All 188 embryonic samples from 43 families were tested with HaploPGT platform, and most of their genetic abnormalities had been determined by different conventional PGT methods beforehand. Among them, there were 12 families only carrying structural rearrangements (115 embryos) in which 9 families accepted implantation and 5 families had normal labor ART outcomes, 7 families only carrying monogenic diseases (26 embryos) and 3 families carrying both structural rearrangements and monogenic diseases (26 embryos). Twelve monopronucleated zygotes (1PN) samples and 9 suspected triploid samples were collected from 21 families. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Here, we raised a comprehensive PGT method called HaploPGT, combining reduced representation genome sequencing, read-count analysis, B allele frequency and haplotyping analysis, to simultaneously detect different genetic disorders in one single test. MAIN RESULTS AND THE ROLE OF CHANCE: With 80 million reads (80M) genomic data, the proportion of windows (1 million base pairs (Mb)) containing two or more informative single nucleotide polymorphism (SNP) sites was 97.81%, meanwhile the genotyping error rate stabilized at a low level (2.19%). Furthermore, the informative SNPs were equally distributed across the genome, and whole-genomic haplotyping was established. Therefore, 80M was chosen to balance the cost and accuracy in HaploPGT. HaploPGT was able to identify abnormal embryos with triploid, global and partial loss of heterozygosity, and even to distinguish parental origin of copy number variation in mosaic and non-mosaic embryos. Besides, by retrospectively analyzing 188 embryonic samples from 43 families, HaploPGT revealed 100% concordance with the available results obtained from reference methods, including PGT-A, PGT-M, PGT-SR and PGT-HLA. LIMITATIONS, REASON FOR CAUTION: Despite the numerous benefits HaploPGT could bring, it still required additional family members to deduce the parental haplotype for identifying balanced translocation and monogenic mutation in tested embryos. In terms of PGT-SR, the additional family member could be a reference embryo with unbalanced translocation. For PGT-M, a proband was normally required. In both cases, genomic information from grandparents or parental siblings might help for haplotyping theoretically. Another restriction was that haploid, and diploid resulting from the duplication of a haploid, could not be told apart by HaploPGT, but it was able to recognize partial loss of heterozygosity in the embryonic genome. In addition, it should be noted that the location of rearrangement breakpoints and the situation of mutation sites were complicated, which meant that partial genetic disorders might not be completely detected. WIDER IMPLICATIONS OF THE FINDINGS: HaploPGT is an efficient and cost-effective detection platform with high clinical value for detecting genetic status. This platform could promote the application of PGT in ART, to increase pregnancy rate and decrease the birth of children with genetic diseases. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from the National Natural Science Foundation of China (81873478, to L.H.), National Key R&D Program of China (2018YFC1003100, to L.H.), the Natural Science Foundation of Hunan Province (Grant 2022JJ30414, to P.X.), Hunan Provincial Grant for Innovative Province Construction (2019SK4012) and the Scientific Research Foundation of Reproductive and Genetic Hospital of China International Trust & Investment Corporation (CITIC)-Xiangya (YNXM-201910). Haplotyping analysis has been licensed to Basecare Co., Ltd. L.K., Y.M., K.K., D.Z., N.L., J.Z. and R.D. are Basecare Co., Ltd employees. The other authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Background & Objective: To analyze whether there is an association between pre-pregnancy lipid parameters and gestational diabetes mellitus (GDM) in women undergoing assisted reproductive technologies (ART), a group especially at risk for GDM, and if so, which parameter is associated the strongest. Methods: Data was collected at the Reproductive and Genetic Hospital CITIC-Xiangya in Changsha, China from January 2017 to December 2018. The measured lipid parameters include LDL (low-density lipoprotein), HDL (high-density lipoprotein), TC (total cholesterol), and TG (triglycerides). Results: 119 (15.5%) of the 767 patients developed GDM. On average, women who developed GDM were older, had a higher BMI, LDL, TC, and TG, and lower HDL. After adjusting for confounders, LDL and HDL showed a significant association with GDM (p < 0.05), but TC and TG did not. Binary LDL/HDL and TC/HDL ratios showed the strongest association with GDM incidence (OR 1.957 [95%CI 1.258–3.044] and 1.942 [1.243–3.034] respectively). Subgroup analysis showed that an elevated LDL/HDL ratio also increased GDM risk in subgroups with a typically lower prevalence of GDM, such as young women with a low BMI and low blood pressure. Both lipid ratios (LDL/HDL and TC/HD) show strong interactions with baseline age, fasting plasma glucose, and LH. Conclusions: In this cohort of Chinese women undergoing ART, pre-pregnancy LDL/HDL and TC/HDL were associated with GDM the strongest from the lipid parameters and could be useful to estimate GDM risk even before ART treatments and pregnancy. Clinical trial number: NCT03503006 registered on the 21st of March 2018 (on clinicaltrials.gov). https://clinicaltrials.gov/study/NCT03503006?locStr=Changsha,%20Hunan,%20China&country=China&state=Hunan&city=Changsha&cond=ivf&rank=2.

Background: It was suggested that vaccination in general might affect reproductive health. Safety of COVID-19 vaccination in women undergoing assisted reproductive techniques (ART) treatment is not well established.Methods: We performed a retrospective study including 536 women undergoing fresh embryo transfer after IVF/ICSI treatment in a huge IVF center in southern China to investigate the effect of COVID-19 vaccination on oocyte maturation, fertilization rate, blastulation rate, implantation rate, clinical pregnancy rate and miscarriage rate. In addition, we performed a systematic review of existing studies on the safety of COVID-19 vaccination in women undergoing ART treatment.Results: In our study, 268 women received inactivated or recombinant COVID-19 vaccination and 268 controls were enrolled based on propensity score matching. We observed a decreased fertilization rate and signs for impaired oocyte maturation in vaccinated women. Besides our study, there were 15 studies analyzing the safety of COVID-19 vaccination in women undergoing ART treatment. For the mRNA vaccines, no adverse signals were reported concerning oocyte maturation, fertilization rate, blastulation rate, implantation rate, clinical pregnancy rate and miscarriage rate. In women being vaccinated with an inactivated vaccine, implantation rate, clinical pregnancy rate and miscarriage rate were not affected, whereas oocyte maturation and fertilization rate were impaired.Conclusions: Vaccination against COVID-19 in women undergoing ART treatment seems to be safe especially for women getting mRNA vaccines. The effects on oocyte maturation and fertilization rate of inactivated and recombinant COVID-19 vaccinations might be a safety signal and need further investigation and independent confirmation.

Do differences in blood pressure within the normal range have any impacts on the live birth rate (primary outcome) or biochemical pregnancy rate (beta-hCG positivity), clinical pregnancy rate (heart beating in ultrasound), abortion rate and ectopic pregnancy rate (secondary outcomes) of fresh embryo transfer in women undergoing their IVF/ICSI treatment? Even rather small differences in baseline blood pressure in women with normal blood pressure according to current guidelines undergoing fresh embryo transfer after IVF/ICSI affects substantially the live birth rate. Pre-pregnancy hypertension is a well-known risk factor for adverse pregnancy events such as preeclampsia, fetal growth restriction, placental abruption and adverse neonatal events. It is likewise well known that hypertension during pregnancy in women undergoing ART is associated with adverse pregnancy outcomes. However, whether blood pressure at the high end of the normal range has an impact on ART is unknown. It is a prospective observational cohort study based on a single IVF center between January 2017 and December 2018. Two thousand four hundred and eighteen women with normal blood pressure undergoing fresh embryo transfer after IVF/ICSI at the Reproductive and Genetic Hospital of CITIC-Xiangya were enrolled in this study. Blood pressure was measured at the first visit when women consulted the IVF center due to infertility. In women with a successful pregnancy outcome (1487 live births out of 2418 women undergoing fresh embryo transfer after IVF/ICSI), systolic blood pressure (SBP) (114.1 ± 9.48 mmHg versus 115.4 ± 9.8 mmHg, P = 0.001) and diastolic blood pressure (DBP) (74.5 ± 7.5 mmHg versus 75.3 ± 7.34 mmHg, P = 0.006) were lower than in those who did not achieve live births. Multivariate logistic regression analysis revealed that SBP (OR: 0.987, 95% CI: 0.979–0.996, P = 0.004) and DBP (OR: 0.986, 95% CI: 0.975–0.998, P = 0.016) were negatively associated with live birth. Similarly, SBP was significantly negatively related to clinical pregnancy rate (OR: 0.990, 95% CI: 0.981–0.999, P = 0.033), while for DBP the association was not statistically significant (OR: 0.994, 95% CI: 0.982–1.006, P = 0.343). However, both SBP and DBP were positively associated with miscarriage OR: 1.021 (95% CI: 1.004–1.037, P = 0.013) and OR: 1.027 (95% CI: 1.005–1.049, P = 0.014), respectively. Both SBP and DBP were unrelated to biochemical pregnancy (hCG positivity), implantation and ectopic pregnancy rate. Whether lowering blood pressure before initiating ART treatment in women with SBP or DBP higher than the thresholds defined in our study will confer a benefit is unknown. Also, we cannot exclude bias due to different ethnicities. Moreover, participants in our study only received fresh embryo transfer, whether the results could apply to frozen embryo transfer is unclear. Our study challenges the current blood pressure goals in women undergoing fresh embryo transfer after IVF/ICSI. Further studies are needed to figure out the mechanism and effective approach to increase IVF/ICSI pregnancy outcomes. Hunan Provincial Grant for Innovative Province Construction (2019SK4012). The authors declare that there were no conflicts of interest in this study. N/A.

Background The risk of developing gestational diabetes mellitus (GDM) is higher in women undergoing assisted reproductive treatment than in women conceiving spontaneously. Objectives To determine whether the GDM risk after day-3 embryo transfer differs from the GDM risk after day-5 blastocyst transfer. Methods Prospective observational study in women becoming pregnant after first fresh embryo or blastocyst transfer. Results 1579 women got pregnant and had life birth. 1300 women got day three embryo transfer only, whereas 279 women received at least one blastocyst. 252 out of the 1579 women developed GDM. Age, body mass index, baseline estradiol, baseline high-density lipoprotein, and progesterone on the day of hCG injection were not different in women receiving day three embryos only versus women receiving at least one blastocyst. The number and quality of retrieved oocytes were not different in women receiving day 3 embryo transfer (ET) from those receiving blastocysts. Our study confirmed already established GDM risk factors such as age and body mass index, baseline estradiol and high-density lipoprotein, as well as progesterone after ovarian stimulation. We could furthermore demonstrate that the GDM incidence in women receiving day five blastocyst transfer was significantly higher than those who received day three embryo transfer (21.15% vs. 14.85%, P=.009). Considering confounding factors, we likewise saw that blastocyst transfer was an independent procedure-related GDM risk factor (P = 0.009, Exp (B): 1.56, 95% CI: 1.12-2.18). Conclusion Blastocyst transfer after IVF/ICSI increases the risk of developing GDM.