【作者】 刘丰；

【导师】 胡志斌；

【作者基本信息】 南京医科大学 ， 流行病与卫生统计学， 2019， 硕士

【摘要】 多胎妊娠是指在一次妊娠中,宫腔内同时有两个或两个以上的胎儿。而多胎活产是指一次分娩两个或两个以上的婴儿,其中至少有一个活产。近年来不孕不育呈现快速增长和年轻化趋势,辅助生殖治疗是主要的行之有效的措施。目前人类辅助生殖技术(assisted reproductive technology,ART)主要包括人工授精(artificial insemination,AI)和体外受精-胚胎移植(in vitro fertilization-embryo transfer,IVF-ET)及其衍生技术,IVF-ET的衍生技术主要包括单精子卵胞浆内注射(intra cytoplasmic sperm injection,ICSI)、冻融胚胎移植(frozen-thawed embryo transfer,FET)、胚胎植入前遗传学诊断(preimplantation genetic disgnosis,PGD)等。自1978年世界首例试管婴儿诞生以来,目前世界范围内每年约进行150万个IVF-ET周期,诞生35万个婴儿。为了提高妊娠率,IVF-ET治疗经常移植两个或更多胚胎,以期增加成功妊娠概率,也正因为如此,辅助生殖治疗大大增加了多胎妊娠的机会。多胎妊娠是ART最常见的并发症,多胎妊娠率的上升与ART的广泛应用是同步的。目前多胎活产儿约占活产儿总数的3%,ART受孕多胎妊娠率约为30%。人类自然妊娠状态下多胎妊娠的发生率与遗传背景、母亲生育年龄、产次等因素有关,除上述因素对多胎妊娠的生物学影响外,卵巢刺激疗法是多胎增加的重要原因。ART治疗过程中的移植胚胎数、获卵数、移植胚胎质量,辅助孵化(assisted hatching,AH)、单精子卵胞浆内注射(intra cytoplasmic sperm injection,ICSI)等胚胎操作、延长胚胎培养时间、囊胚移植等均可能影响多胎妊娠的发生。在多胎妊娠过程中,可能会出现早期胚胎未能继续发育,最终分娩出胎儿数量小于妊娠早期胚胎数量的现象,这种现象称为自然减胎。早期多胎妊娠经历自然减胎后可表现为单胎或多胎活产。ART治疗的自然减胎发生率在5%-52.6%不等,约为30%左右。既往有发现在IVF多胎妊娠中,子宫内膜厚度和移植胚胎数是自然减胎的独立预测因素,但其研究样本量较小,结果存在一定局限性,还应进一步研究以深入了解辅助生殖自然减胎的影响因素。综上所述,辅助生殖过程增大了多胎妊娠的发生率,患者个人因素和治疗因素均可能对多胎妊娠和自然减胎造成影响,但具体哪些因素有影响,如何影响,尚不完全明确。鉴于辅助生殖过程中多胎妊娠及自然减胎对母儿健康的潜在不良影响,本研究拟基于多中心辅助生殖诊疗数据,采用大样本病例-对照研究设计,在第一部分中探讨患者个人因素和辅助生殖治疗因素对多胎妊娠的影响,在第二部分中研究自然减胎的影响因素。通过上述两部分的研究,探索影响辅助生殖多胎活产的因素。第一部分:辅助生殖多胎妊娠的影响因素背景:随着人类辅助生殖技术的广泛应用,随之而来的医源性多胎妊娠问题日益严重。2016年中国生殖医学中心多胎妊娠率仍超过30%。既往已有研究对影响辅助生殖多胎妊娠的因素进行了探索,Groeneveld等人基于6 598名荷兰女性IVF/ICSI治疗周期数据的研究显示,促排卵治疗获得的卵母细胞数量较多与双胚胎移植后异卵双胞胎风险增加有关。Kim和Abdollahi也报道了年龄和胚胎质量与多胎妊娠之间的关联。对于单胚胎移植中的同卵双胎,ICSI、AH均可能增加其风险,而Liu等人的研究仅发现延长胚胎培养时间与同卵双胎风险增加有关。因此,目前对于辅助生殖多胎妊娠的影响因素仍不十分清楚。方法:研究纳入2013年1月至2016年12月期间在南京医科大学第一附属医院、南京医科大学附属妇产医院、郑州大学第三附属医院,和中国医科大学附属盛京医院四个医院生殖中心接受辅助生殖治疗并临床妊娠的患者为研究对象,共计19 434例,其中单胎妊娠14 765例,多胎妊娠4 669例,采用Logistic回归模型的比值比(Odds ratio,OR)及其95%置信区间(confidence interval,CI)评估患者个体因素和临床因素与多胎妊娠的关联。采用R软件进行统计分析(3.3.3版)。所有统计学检验均为双侧检验,检验水准α=0.05。结果:本研究中多胎妊娠的总体发生率为24.0%(4 669/19 434)。与单胎妊娠相比,多胎妊娠的孕妇年龄明显较小,不孕年限较短,促性腺激素剂量和hCG日子宫内膜厚度较大,hCG日孕酮水平、获卵数和累计胚胎评分较高。在多胎妊娠周期中,更倾向于采用新鲜胚胎移植,不孕类型为原发不孕,移植两个胚胎和卵裂期胚胎。在单因素Logistic回归分析中,除不孕年限、hCG日雌二醇、受精方式外,其余因素均与多胎妊娠的概率相关。在多因素Logistic回归分析中,移植两个胚胎是多胎妊娠最主要的影响因素,与单胎妊娠相比比值比(OR):36.54,95%置信区间(95%CI):27.89-47.86。年龄、周期类型、hCG日孕酮水平、获卵数、移植胚胎阶段、累计胚胎评分与双胚胎移植后多胎妊娠相关,OR(95%CI)分别为:0.62(0.55-0.70)、0.84(0.77-0.92)、0.86(0.80-0.92)、1.21(1.12-1.31)、1.28(1.13-1.46)、1.19(1.15-1.23)。单胚胎移植后,仅高累计胚胎评分与多胎妊娠风险降低有关(OR:0.68;95%CI:0.47-0.99)。结论:移植胚胎数、年龄、周期类型、hCG日孕酮水平、获卵数、移植胚胎阶段、累计胚胎评分是辅助生殖治疗后多胎妊娠的影响因素。第二部分:辅助生殖多胎妊娠自然减胎的影响因素背景:辅助生殖技术的快速普及使得在该治疗中出现的异常事件受到广泛关注。多胎妊娠是辅助生殖的最常见合并症。减少多胎妊娠的胎儿数可降低母体孕产期并发症发生率,改善围产儿结局。因此,多胎妊娠减胎术(multifetal pregnancy reduction,MFPR)成为处理一级预防多胎妊娠失败的主要手段。但即使没有行MFPR的多胎妊娠也可能出现自然减胎现象。自然减胎可能增加新生儿脑瘫、早产和极低出生体重的风险。虽然在考虑进行MFPR时,必须正确看待自然减胎发生的相对频率,但目前对造成其发生风险的因素了解得相对较少,且研究样本量较小,结果存在一定局限性。方法:选取2013年1月至2016年12月在南京医科大学第一附属医院、南京医科大学附属南京市妇产医院和中国医科大学附属盛京医院辅助生殖中心接受IVF-ET和ICSI治疗的患者为研究对象,研究纳入经辅助生殖治疗后确定临床妊娠、且孕囊数为2个的双胎妊娠,并最终活产的患者。本研究共纳入2 851个双胎妊娠辅助生殖周期,其中发生自然减胎的686个周期作为病例组,成功分娩双胞胎的2 165个经过年龄频数匹配的周期作为对照组。采用Logistic回归模型分析自然减胎的相关因素。结果:本研究中自然减胎的总体发生率为18.8%(686/3 648)。自然减胎组和正常妊娠组的年龄分别为(30.55±4.31)和(30.25±4.02)岁,差异无统计学意义(P=0.217)。在单因素Logistic回归分析中,上述两组间存在统计学差异的变量:男方不育因素、促性腺激素剂量、h CG日雌二醇和促黄体生成素水平、移植胚胎数、移植胚胎阶段以及h CG日子宫内膜类型均与自然减胎相关。多因素Logistic回归结果显示:在调整男方不育因素、促性腺激素剂量、h CG日雌二醇、移植胚胎数、移植胚胎类型、h CG日子宫内膜类型之后,与h CG日促黄体生成素水平小于2.76 IU/L相比,其水平高于2.76 IU/L的孕妇发生自然减胎事件的风险增加了33%(OR=1.33,95%CI=1.01-1.75,P=0.043)。与移植1个胚胎相比,当移植3个胚胎时,孕妇发生自然减胎事件的OR(95%CI)为0.24(0.08-0.74)。在囊胚期进行胚胎移植相比卵裂期胚胎移植发生自然减胎事件的风险降低了57%(OR=0.43,95%CI=0.28-0.68,P<0.001)。结论:hCG日促黄体生成素水平、移植胚胎数和移植胚胎阶段是辅助生殖双胎妊娠自然减胎的相关因素。更多还原

【Abstract】 Multiple pregnancy refers to a pregnancy in which there are two or more fetuses in the uterus at the same time.And a multiple birth was defined as the birth of two or more infants,at least one of whom was live-born.Infertility has shown rapid growth and younger trend in recent years,and assisted reproductive treatment is the main effective measure.At present,the assisted reproductive technology(ART)mainly includes artificial insemination(AI)and in vitro fertilization-embryo transfer(IVF-ET)and its derivative technology.The derivative technology of IVF-ET mainly includes intra cytoplasmic sperm injection(ICSI),frozen-thawed embryo transfer(FET),and preimplantation genetic disgnosis(PGD).Currently,approximately 1.5 million cycles of IVF are performed annually,resulting in the birth of 350,000 babies in worldwide since first ART-conceived infant was born in 1978.In order to improve clinical pregnancy rates,IVF-ET treatment usually transplants two or more embryos,and as such,assisted reproductive treatment greatly increases the chances of multiple pregnancies.Multiple pregnancies are the most common complication of ART,and the rise in multiple pregnancies is synchronous with the widespread use of ART.At present,multiple live births account for about 3% of the total number of live births,and the rate of multiple pregnancies with ART is about 30%.The incidence of multiple pregnancies in human natural pregnancy is related to genetic background,maternal reproductive age,and parity.In addition to the biological effects of these factors,ovarian stimulation therapy is an important cause of multiple births.The number of transplanted embryos,the number of eggs obtained,the quality of transplanted embryos,assisted hatching(AH),intracytoplasmic sperm injection(ICSI)and other embryo manipulations,prolonged embryo culture time,blastocyst transplantation etc.may affect the occurrence of multiple pregnancies during ART treatment.In the process of multiple pregnancies,there may be a phenomenon that the early embryo fails to continue to develop,and the number of the final delivered fetus is less than the number of early pregnancy embryo,which is called spontaneous reduction.The incidence of spontaneous reduction with ART ranged from 5% to 52.6%,about 30%.It has been found in previous studies that endometrial thickness and the number of transferred embryos were independent predictors of spontaneous reduction in IVF conceived multiple pregnancies.However,due to the small sample size,the results had some limitations.Further studies were conducted to further understand the influencing factors of spontaneous reduction following assisted reproductive technology.In summary,the assisted reproductive process increases the incidence of multiple pregnancies.Individual factors and clinical treatment factors may affect multiple pregnancies and spontaneous reduction.However,which factors have an impact and how it affected remains unclear.In view of the potential adverse effects of multiple pregnancies and spontaneous reduction on maternal and child health during assisted reproduction,our study was based on multi-center assisted reproductive diagnosis data,using a large sample case-control study design,in the first part to explore patients’ personal factors and assisted reproductive treatment factors on multiple pregnancies,in the second part to explore the influencing factors of spontaneous reduction.Through the above two parts of research,explore the factors affecting the multiple births of assisted reproductive.Part Ⅰ: Study on the influencing factors of multiple pregnancies after assisted reproduction technologyBackground: With the widespread use of human assisted reproductive technology,the consequent iatrogenic multiple pregnancy problems have become increasingly serious.In 2016,the rate of multiple pregnancies in China’s reproductive medicine center still exceeded 30%.Previous studies have explored factors affecting multiple pregnancies following ART treatment.Groeneveld et al.showed that the higher number of oocytes obtained from ovulation induction therapy was associated with an increased risk of dizygotic twins after double embryo transfer based on data from 6 598 Dutch women with IVF/ICSI treatment.Kim and Abdollahi also reported the association between age and embryo quality and multiple pregnancies.With regard to monozygotic twins in single embryo transfer,ICSI and AH may increase the risk,while Liu et al.only found that prolonging embryo culture time was associated with increased risk of monozygotic twins.Therefore,the current influencing factors for assisted reproductive multiple pregnancies are still unclear.Methods: The study included 19 434 embryo transferred cycles(14 765 singleton pregnancy cycles,4 669 multiple pregnancy cycles)resulted in clinical pregnancy from four reproductive centers in China(the First Affiliated Hospital of Nanjing Medical University,the Obstetrics and gynecology Hospital Affiliated to Nanjing Medical University,the Third Affiliated Hospital of Zhengzhou University,and the Shengjing Hospital of China Medical University),during January 2013 and December 2016.The odds ratio(OR)of the logistic regression model and its 95% confidence interval(CI)were used to assess the association of individual and clinical factors with multiple pregnancies.Statistical analysis was performed using R software(version 3.3.3).All statistical tests are two-sided test,test level α=0.05Result: In this study,the overall incidence of multiple pregnancies was 24.0% of all clinical pregnancies.Compared with singleton pregnancies,the age of women with multiple pregnancies is significantly younger,the duration of infertility is shorter,the dose of gonadotropin and the endometrial thickness on h CG trigger day are larger,and the progesterone level on h CG trigger day,the number of oocycts obtained and the cumulative embryo score are higher.In the multiple pregnancies cycles,fresh embryo transfer is preferred,and the infertility type is primary infertility,and two embryos and cleavage stage embryos are transplanted.In the univariate analysis,except for duration of infertility,estradiol level on h CG trigger day,and fertilization methods,the other factors were related to the probability of multiple pregnancies.In multivariable logistic regression analysis,transplanting two embryos was the major factor in multiple pregnancies,and the OR compared with single embryo transfer was 36.54,95% CI: 27.89-47.86.Age,cycle type,progesterone level on h CG trigger day,number of oocytes retrieved,stage of embryo transferred and cumulative embryo score were associated with multiple pregnancies from double embryo transfer(OR(95% CI)were: 0.62(0.55-0.70),0.84(0.77-0.92),0.86(0.80-0.92),1.21(1.12-1.31),1.28(1.13-1.46),1.19(1.15-1.23),respectively).High cumulative embryo score was the only factor associated with decreased risk of multiple pregnancies from single embryo transfer(OR: 0.68;95% CI: 0.47-0.99).Conclusion: Number of embryos transferred,age,cycle type,progesterone level on h CG trigger day,number of oocytes retrieved,stage of embryo transferred and cumulative embryo score were identified as related factors of multiple pregnancies following assisted reproductive technology.Part Ⅱ: Analysis on factors related to spontaneous reduction in twin pregnancy following assisted reproductive technologyBackground: The rapid spread of assisted reproductive technology has led to widespread attention in the anomalous event that occurred in this treatment.Multiple pregnancies are the most common complication of assisted reproduction.Reducing the number of fetuses in multiple pregnancies can reduce the incidence of maternal complications during pregnancy and improve perinatal outcomes.Therefore,multifetal pregnancy reduction(MFPR)has become the primary means to treat failure of primary prevention of multiple pregnancies.However,even if there are multiple pregnancies without MFPR,spontaneous fetal reduction may occur.Spontaneous reduction may increase the risk of neonatal cerebral palsy,premature birth and very low birth weight.Although the relative frequency of spontaneous reduction must be correctly considered when considering the MFPR,the factors causing the risk are relatively poorly understood,and the research sample size is small with certain limitations.Methods: 2 851 twin pregnant women after treatment of IVF-ET or ICSI cycles were enrolled at Assisted Reproductive Centre of the First Affiliated Hospital of Nanjing edical University,Nanjing Maternity Hospital and Shengjing Hospital of China Medical University from January 2013 to December 2016 respectively.According to the pregnancy outcome,the patients with spontaneous reduction were classified as case group(n=686),and those with normal twin birth after age frequency matching were classified as control group(n=2 165).Logistic regression model was used to analyze the related factors of the occurrence of spontaneous reduction.Result: The overall incidence of spontaneous reduction in this study was 18.8%(686/3648).The age of case group and control group were(30.55 ± 4.31)and(30.25 ± 4.02)years old respectively.In the univariate analysis,these statistically significant variables between the two groups: male infertility factor,gonadotropin dose,estradiol and luteinizing hormone level on h CG trigger day,number of embryo transferred,stage of embryo transferred,and endometrial type on h CG trigger day are associated with spontaneous reduction.After adjustment of male infertility factor,gonadotropin dose,estradiol level on h CG trigger day,number of embryo transferred,stage of embryo transferred,and endometrial type on h CG trigger day,multivariate logistic regression showed that compared with women with luteinizing hormone level less than 2.76 IU/L,the risk of spontaneous reduction increased by 33% of those with luteinizing hormone level higher than 2.76 IU/L(OR=1.33,95% CI=1.01-1.75,P=0.043).When transplanting 3 embryos,the OR(95% CI)of spontaneous reduction in pregnant women was 0.24(0.08-0.74).Embryo transfer at the blastocyst stage was 57% lower risk than that at the cleavage stage(OR=0.43,95% CI=0.28-0.68,P<0.001).Conclusion: Luteinizing hormone level on h CG trigger day,number and stage of embryo transfer were related factors to spontaneous reduction in twin pregnancy following assisted reproductive technology.更多还原