[Profile of China National Birth Cohort].

With the rapid changes in lifestyle, natural and social environment, the reproductive health status of couples in childbearing age continues to decline, and long-term outcomes of the rapidly increasing offspring conceived by assisted reproductive technology (ART) needs to be evaluated urgently. Therefore, the focus of research now needs to be extended from death and severe diseases to full life cycle and full disease spectrum. In order to meet the demand for such research, we launched the China National Birth Cohort (CNBC) study, an ongoing prospective and longitudinal study aiming to recruit 30 000 families underwent ART and 30 000 families with spontaneous pregnancies. Long-term follow-up programs will be conducted for both spouses and their offspring. Data of couples and their offspring, such as environmental exposure, reproductive history, psychological and behavioral status, will be collected during follow-up. Peripheral blood, urine, umbilical blood, follicular fluid, semen were also collected at different follow-up nodes. Based on high-quality data and biological samples, CNBC will play an extremely important supporting role and have a far-reaching impact on maternal and children's health care and reproductive health in China. This paper is exactly a brief introduction to the construction and basic design of CNBC.

[Baseline characteristics of the participants of China National Birth Cohort].

Objective: To explore the effects of environmental, genetic factors as well as the interactions in early life on the short-term and long-term health of offspring and to systematically evaluate the pregnancy outcomes and health of offspring after birth between families with assisted reproductive technology (ART) conception and families with spontaneous conception. Methods: The China National Birth Cohort (CNBC), a multicenter prospective birth cohort study, includes both families with ART conception and families with spontaneous conception. Since 2016, CNBC has recruited families from 24 hospitals located in 12 provinces, municipalities and autonomous regions throughout China. Information and biospecimens were collected before ART treatment, embryo transfer, at early, second, third trimester and delivery, and at 42 days, 6, 12 and 36 months after birth. Results: By June 2020, CNBC had included 27 044 families with ART conception and 29 589 families with spontaneous conception. The majority of the participants are urban residents. Among the families with ART conception, 65.5% of the men and 63.7% of the women had college degrees or higher. The mean age distribution of men and women was (33.83±5.52) and (32.38±4.67) years. 83.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.8% and 2.1% in women. Among the families with spontaneous conception, 81.5% of the men and 86.5% of the women had college degrees or higher. The mean age distribution of men and women was (32.06±5.09) and (30.40±4.27) years. 67.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.1% and 2.2% in women. The baseline characteristics were different between the families with ART conception and spontaneous conception in different regions. Conclusion: CNBC provides a powerful and rich resource in studying the impact of genetic, environmental factors and interactions in early life and ART treatment on the health of offspring after birth.

[Comparison of the etiological constitution of two and three or more recurrent miscarriage].

Objective: To compare the etiological constitution of recurrent miscarriage (RM) between patients with consecutive two and three or more miscarriages through combining the routine examination results and embryonic karyotype. Methods: Patients with a history of two or more consecutive clinical miscarriages (≤12 weeks of gestation) consulting in the RM clinic of the First Affiliated Hospital of Sun Yat-sen University from March 2011 to January 2016 were collected. Six hundred and ninety-six with detailed history recorded, routine clinical examinations of RM and at least once embryonic karyotype were ultimately enrolled in this study. Their etiological constitution of RM were analyzed in groups of consecutive two and three or more miscarriage. The etiologies of RM in analysis consisted of women age, body mass index (BMI) , chromosome abnormalities of couples, uterine abnormalities, endocrinology abnormalities and antiphospholipid syndrome (APS) . Results: (1) Among 696 patients, the abnormal embryonic karyotypes was 60.6% (422/696) and routine RM etiologies was 32.2% (224/696) , leaving the ratio of unexplained RM was only 29.0% (202/696). (2) A total of 717 embryo karyotype were found in 696 patients, included21 cases with twice embryo karyotype results the percentage of normal embryo was 39.7% (285/717) , while abnormal ones was 60.3% (432/717). Among the types of abnormal karyotype, the most common ones (>10%) were trisomy 16 (19.2%, 83/432) , monosome X (11.3%, 49/432) and trisomy 22 (10.9%, 47/432). (3) Among the 696 RM patients, the number of two and three or more miscarriages were respectively 446 (64.1%, 446/696) and 250 (35.9%, 250/696). Comparing groups of three or more miscarriages with two miscarriages, there were significant differencein older age as well as uterine adhesion (P<0.05). But no difference was found in body mass index (BMI) , the rates of chromosome abnormalities of couples, uterine abnormalities except uterine adhesion, endocrinology abnormalities and APS (all P>0.05) between two groups. Conclusions: The abnormal embryonic karyotype is the most common cause of first-trimester RM. The etiological constitution of two and three or more recurrent miscarriages is accordant, suggesting that routine clinical examination and the embryonic karyotype should be started following two consecutive clinical early miscarriages.

Epigenetic changes of histone deacetylation in murine oocytes matured in vitro versus in vivo.

OBJECTIVE: In this study, we studied changes in histone acetylation during mouse oocytes meiosis. The aim was to investigate HDAC1 expression patterns in the mouse oocytes and effects of in-vitro maturation on epigenetic modifications during meiosis. MATERIALS AND METHODS: Immature and mature oocytes were collected from female Kunming white mice of 4-6 weeks in age. Dynamic changes of histone H3K9, H4K12 acetylation were explored. HDAC1 spatial and temporal expression patterns during meiosis and their expression changes in in-vitro maturation were determined. RESULTS: It was found that histone H3K9 and H4K12 acetylations were gradually disappeared during the meiotic maturation of mouse oocytes. HDAC1 proteins were localized mainly throughout the nucleoplasm in GV-intact oocyte, and colocalized with chromosomes at metaphase II (MII). The acetylated H3K9 and H4K12 were absent in oocytes matured in vivo, while the elevated acetylation of H3K9 and H4K12 was detected in oocytes matured in vitro. When cultured in vitro, the decrease of HDAC1 protein level and mRNA level were observed compared with oocytes matured in vivo. CONCLUSIONS: the acetylation of H3K9, H4K12 decreased gradually to undetectable during oocyte meiosis. The histone deacetylation in oocytes was inadequate during in vitro maturation, and the in vitro maturation might lead to reduced HDAC1 expression in oocytes.

[Clinical analysis of preimplantation genetic diagnosis with HLA matching for beta-thalassemia].

OBJECTIVE: To investigate the efficacy and feasibility of preimplantation genetic diagnosis(PGD)with human leukocyte antigen(HLA)matching for beta-thalassemia. METHODS: A total of 43 referred beta-thalassemia couples, with at least on child in need of hematopoietic stem cell transplantation(HSCT), underwent PGD for HLA matching at the First Affiliated Hospital of Sun Yat-sen University from 2010 to 2015. PGD cycles of these couples were retrospectively analyzed, and 15 infants born from PGD-HLA were followed up. RESULTS: A total of 84 oocyte retrieval cycles were performed, providing 14±7 oocytes per cycle. Fifty nine embryos biopsied cycles were done, including 24 cleavage stage and 35 blastocyst stage biopsy cycles. In cleavage stage, 259 embryos were biopsied, 93.4%(242/259)of them with conclusive molecular diagnosis, and the percentage of unaffected embryos(normo-homozygote and heterozygote)was 71.4%(185/259). The percentage of HLA matched unaffected embryos was 9.3%(24/259). In blastocyst stage, 306 embryos were biopsied, while 93.8%(287/306)of them were conclusive, and the percentage of unaffected embryos was 70.6%(216/306). The percentage of HLA matched unaffected embryos in blastocyst stage biopsy was 14.4%(44/306), which was higher than in cleavage stage biopsy(P< 0.05). Forty three female carriers underwent 48 embryo transfer cycles including 3 fresh and 45 frozen-thawed embryo transfer cycles. Three fresh embryo transfer cycles were done after cleavage stage biopsy, resulted in a birth of healthy twins born at 36 weeks' gestation. All the embryos were frozen after blastocyst biopsied. Totally, 54 frozen-thawed embryos that were transferred in 45 frozen-thawed embryo transfer cycles included 25 embryo from cleavage stage biopsy and 29 embryo from blastocyst stage biopsy, and 42 of them were HLA matched. Clinical pregnancy rate and implantation rate per cycle in frozen-thawed embryo transfer were 38%(17/45)and 37%(20/54)respectively. A total of 15 infants were born, 2 were from a fresh embryo transfer cycle, and 13 were from frozen-thawed embryo transfer cycles. RESULTS of prenatal diagnosis from delivered cases were matched to that of PGD. Four sick children have been cured by HSCT from these HLA matched born siblings. CONCLUSION: PGD with HLA matching is an established method for conceiving a child who may donate hematopoietic stem cells to save an ill sibling.

[Spontaneous ovulation in in vitro fertilization-embryo transfer cycles using gonadotropin-releasing hormone antagonist: a large-sample retrospective study].

OBJECTIVE: To investigate the premature spontaneous ovulation rates in in vitro fertilization-embryo transfer (IVF-ET) cycles using gonadotropin-releasing hormone antagonist (GnRH-ant) and gonadotropin-releasing hormone agonist (GnRH-a), as well as the risk factors for premature spontaneous ovulation. METHODS: The rates of premature spontaneous ovulation in a total of 10 612 cycles using GnRH-ant or GnRH-a were compared. Matched case-controlled study and binary logistic regression model were conducted to analyze the risk factors for premature spontaneous ovulation. RESULTS: The spontaneous ovulation rate in the whole for GnRH-a cycles was 0.15% (13/8 514), compared with a 1.62% (34/2 098) in GnRH-ant cycles (P<0.01). Further matched controlled study and regression analyze found out that higher basal FSH level was a predominant risk and prediction factor for spontaneous ovulation (OR=1.20, P=0.009). CONCLUSIONS: In GnRH-ant cycles, spontaneous ovulation rate is about 10 times than which in GnRH-a cycles. Diminished ovarian function is a predominate risk factor for premature spontaneous ovulation.

Comparison of the survival of human biopsied embryos after cryopreservation with four different methods using non-transferable embryos.

BACKGROUND: The standard embryo cryopreservation method is still less than optimal for biopsied embryos. The aim of this study was to compare the survival of biopsied embryos cryopreserved with four different methods using non-transferable embryos. METHODS: Abnormal embryos from one or three pronuclei and spare embryos of grade 3 and 4 were used for this study. Non-biopsied embryos were cryopreserved using the standard method as control. Biopsied embryos were cryopreserved using four methods as follows: standard method, modified freezing method, modified thawing method and vitrification. Blastomere survival and blastulation of frozen-thawed embryos were compared between the different methods. RESULTS: The proportion of embryos with > or = 50% blastomere survival and total blastomere survival rate of biopsied embryos were significantly higher with vitrification than the other three methods. Both the modified freezing and modified thawing methods had significantly higher embryo survival and total blastomere survival rates than standard methods. However, there was no significant difference in blastulation of surviving embryos in all the five groups. CONCLUSIONS: Non-transferable embryos derived from clinical IVF/ICSI are useful for evaluation of the optimal freezing procedures for biopsied embryos. Vitrification increases the survival rate of human biopsied embryos above standard and modified cryopreservation methods.

A biochemical study on combined treatment of experimental silicosis with tetradrine-PVNO and tetradrine-QOHP in rats.

A better understanding is needed to explain the mechanism of therapeutic effect of combined use of tetradrine-PVNO and tetradrine-QOHP which play very important roles in treatment of silicosis. Blood prolidase (PLD), monamine oxidase (MAO) and plasminogen (PLG) in silicotic rats after treatment with tetradrine-PVNO or tetradrine-QOHP were measured. The values obtained were compared with the untreated silicotic rats. It was found that the silicotic rats that received tetradrine-PVNO showed significant increase in PLD and decrease in PLG, but no significant change in MAO. The PLD in plasma of silicotic rats that received tetradrine-QOHP were elevated significantly, but PLG and MAO did not change appreciably. These findings suggest that the combined use of tetradrine-PVNO and tetradrine-QOHP can accelerate the degradation of collagen in silicotic rats.

[The effect of co-administration of low dosage growth hormone and gonadotropin for ovarian hyperstimulation in vitro fertilization and embryo transfer].

The co-administration of low dosage growth hormone (GH) and gonadotropin (Gn) to women with suboptimal response to GnRH-a/hMG/hCG hyperstimulation regimen during previous cycles in in vitro fertilization-embryo transfer (IVF-ET) might be beneficial by promoting the maturation of oocytes, improving the fertilization rate and increasing the number of embryos replaced. Our results showed the pregnancy rate increased significantly. However, this protocol neither enhanced ovarian response to Gn, nor reduced Gn dosage required for follicular recruitment. The levels of insulin-like growth factor I (IGF-I) in the co-treatment group increased from 150 +/- 44 micrograms/L to 222 +/- 46 micrograms/L (P < 0.01) during the administration of GH. These increased significantly as compared with the control group. The present study showed that the administration of GH in low doses is effective.