Abstract
目的
分析囊胚移植相关因素对体外受精-胚胎移植妊娠结局的影响。
方法
回顾性分析2015年7月−2020年7月期间在我院接受体外受精-胚胎移植的790例患者的临床资料，比较第5天胚胎囊胚（D5）组（n=705）和第6天胚胎囊胚（D6）组（n=85）囊胚移植的妊娠结局；依据妊娠结局分为活产组（n=322）和非活产组（n=468），多因素logistic分析体外受精-胚胎移植后活产结局的囊胚移植相关影响因素。
结果
D5组囊胚移植的生化妊娠率、临床妊娠率和活产率（分别为69.93%、64.96%、41.84%）均高于D6组（50.59%、45.88%、30.59%）囊胚移植，差异有统计学意义（P<0.05）；D5组和D6组囊胚移植的流产率比较差异无统计学意义。多因素logistic分析显示，年龄>35岁、不孕年限>5年、移植日内膜厚度<9 mm、滋养层细胞评级为C级、囊胚移植日为D6、多产均为体外受精-胚胎移植非活产的危险因素（P<0.05）。
结论
年龄、不孕年限、移植日内膜厚度、滋养层细胞评级、囊胚移植日、多产均与体外受精-胚胎移植的不良妊娠结局相关，应积极监测，采取有效措施预防不良妊娠结局。
Keywords: 体外受精, 胚胎移植, 妊娠结局, 影响因素
Abstract
Objective
To analyze the effect of factors relevant to blastocyst transfer on the pregnancy outcome of in vitro fertilization-embryo transfer (IVF-ET).
Methods
The clinical data of 790 pregnant women who underwent IVF-ET in our hospital from July 2015 to July 2020 were retrospectively analyzed. The pregnancy outcome of blastocysts transferred on day 5 (D5, n=705) and those transferred on day 6 (D6, n=85) were compared. According to the pregnancy outcome, the cases were divided into a live birth group (n=322) and a non-live birth group (n=468), and multivariate logistic regression was conducted to study the effect of factors relevant to blastocyst transfer on the live birth outcome of IVF-ET.
Results
In the D5 group, the biochemical pregnancy rate, clinical pregnancy rate and live birth rate of blastocyst transfer were 69.93%, 64.96%, and 41.84%, respectively, which were significantly higher than those of the D6 group at 50.59%, 45.88%, and 30.59%, respectively. The difference was statistically significant (P<0.05). There was no statistically significant difference in the miscarriage rate between the D5 group and the D6 group (P>0.05). Multivariate logistic analysis revealed that age>35 years, years of infertility>5 years, endometrium thickness<9 mm on the day of blastocyst transfer, trophoblast cell rating of C, blastocyst transfer performed on D6, and multiparity were all risk factors for non-live birth outcome of IVF-ET (P<0.05).
Conclusion
The adverse pregnancy outcomes of IVF-ET were found to be associated with age, duration of infertility, endometrial thickness on the day of to blastocyst transfer, trophoblast cell rating, and blastocyst transfer performed after how many days of embryo development, and multiparity, which should be closely monitored, and effective measures should be adopted accordingly to prevent adverse outcomes of pregnancy.
Keywords: In vitro fertilization , Embryo transfer, Pregnancy outcome, Influencing factors
目前对于辅助生殖技术的治疗研究主要集中于子宫内膜容受性、年龄、卵巢功能等方面，但对于妊娠结局相关因素的研究还相对较少[1-2]，而明确体外受精-胚胎移植过程中与妊娠结局相关的危险因素，对于改善提高临床妊娠结局有重要意义[3-4]。已有研究指出[5-6]，胎儿活产率与孕妇的年龄相关，随着孕妇年龄的加大胎儿活产率不断降低，胎儿活产率不仅与孕妇年龄相关，与囊胚移植日、囊胚移植时子宫内膜厚度和滋养层细胞等情况也密切相关[7-8]。但临床中并无较多囊胚移植相关因素对体外受精-胚胎移植妊娠结局影响的相关研究，对于该领域的认识尚浅，因此本研究通过回顾性病例分析，探讨了囊胚移植相关因素对体外受精-胚胎移植妊娠结局的影响，以期通过有效预防措施改善妊娠结局。现分析报道如下。
1. 资料与方法
1.1. 一般资料
回顾性分析2015年7月−2020年7月期间在我院接受体外受精-胚胎移植的共790例患者的临床资料，其中移植2个胚胎囊胚339例，移植3个胚胎囊胚451例。孕妇年龄29～43岁，平均（33.94±4.20）岁，平均体质量指数（BMI）为（21.32±1.43）kg/m2，平均不孕年限为（5.83±1.32）年。本研究已通过郑州大学第二附属医院医学部伦理委员会批准（批准号20150601）。
纳入标准：①夫妻双方染色体检测报告均正常者；②待孕妇女宫腔形态无异常者；③首个新鲜移植周期者；④获卵个数为5个以上者；⑤病历资料完整且随访结果正常者。
排除标准：①因女性子宫异常（子宫肌瘤、子宫腺肌症、子宫瘢痕、子宫内膜息肉、子宫内膜异位症）而不孕者；②子宫畸形者；③严重内分泌疾病（甲状腺、肾上腺等功能异常）者；④凝血功能异常者；⑤中途退出研究、资料不完整或失访者等。
1.2. 观察指标
①囊胚移植与妊娠结局：比较第5天胚胎囊胚（D5）组和第6天胚胎囊胚（D6）组囊胚移植的妊娠结局，包括生化妊娠率、临床妊娠率、流产率和活产率（活产即出生后存在生命体征）。②单因素分析：回顾性分析并比较活产组和非活产组患者的临床资料和随访资料，包括年龄（≤35岁、>35岁）、BMI、女性不孕年限（≤5年、>5年）、促卵泡素（FSH）、移植日内膜厚度、移植日子宫内膜形态、优质囊胚率、内细胞团评级、滋养层细胞评级、囊胚腔扩张阶段、多产率（多产指一胎生产两个及以上新生儿）。③多因素logistic分析体外受精-胚胎移植活产结局的影响因素。
1.3. 统计学方法
计量资料组间比较为t检验，计数资料组间比较为卡方检验，并将P<0.05的因素纳入多因素logistic回归分析。P<0.05为差异有统计学意义。
2. 结果
2.1. 妊娠结局比较
D5组囊胚移植的生化妊娠率、临床妊娠率和活产率均高于D6组囊胚移植，差异有统计学意义（P<0.05）；但两组间囊胚移植的流产率比较差异无统计学意义。见表1。
表 1. Comparison of pregnancy outcome of blastocyst transfer between group D5 and group D6.
D5组和D6组囊胚移植的妊娠结局比较
| Group | n | Biochemical pregnancy rate/case (%) | Clinical pregnancy rate/case (%) | Miscarriage rate/case (%) | Live birth rate/case (%) |
| D5 | 705 | 493 (69.93) | 458 (64.96) | 62 (8.79) | 295 (41.84) |
| D6 | 85 | 43 (50.59) | 39 (45.88) | 9 (10.59) | 27 (31.76) |
| χ 2 | 6.883 | 4.739 | 2.654 | 12.115 | |
| P | 0.022 | 0.042 | 0.062 | 0.002 |
2.2. 影响囊胚移植妊娠结局的单因素分析
活产组孕妇年龄、不孕年限、移植日子宫内膜厚度、优质囊胚率、内细胞团评级、滋养层细胞评级、多产率、囊胚移植日与非活产组相比差异均有统计学意义（P<0.05）。活产组的BMI、FSH、移植日子宫内膜形态与非活产组相比差异均无统计学意义。见表2。
表 2. Analysis of single factors affecting pregnancy outcome of blastocyst transfer.
影响囊胚移植妊娠结局的单因素分析
| Variable | Live birth group (n=322) | Non-live birth group (n=468) | χ2/t | P |
| Age≤35 yr., case (%) | 228 (70.81) | 257 (54.91) | 4.612 | 0.043 |
BMI/(kg/m2),
±s
|
21.06±1.30 | 21.52±1.56 | 1.671 | 0.094 |
| Female infertility≤5 years, case (%) | 218 (67.70) | 239 (51.07) | 7.921 | 0.012 |
FSH/(U/L),
±s
|
7.12±0.65 | 7.20±0.74 | 1.597 | 0.201 |
Endometrial thickness on transplantation day/mm,
±s
|
9.37±0.71 | 8.40±0.88 | 2.253 | 0.038 |
| Endometrial morphology on the day of transplantation/case (%) | 2.317 | 0.065 | ||
| Grade A | 5 (1.55) | 9 (1.92) | ||
| Grade B | 45 (13.98) | 65 (13.89) | ||
| Grade C | 272 (84.47) | 394 (84.19) | ||
| High-quality blastocyst rate/case (%) | 234 (72.67) | 293 (62.61) | 8.036 | 0.011 |
| Inner cell cluster rating/case (%) | 5.629 | 0.034 | ||
| Grade A | 132 (40.99) | 166 (35.47) | ||
| Grade B | 131 (40.69) | 163 (34.83) | ||
| Grade C | 59 (18.32) | 139 (29.70) | ||
| Trophoblast cell rating/case (%) | 6.389 | 0.027 | ||
| Grade A | 130 (40.37) | 153 (32.70) | ||
| Grade B | 130 (40.37) | 145 (30.98) | ||
| Grade C | 62 (19.26) | 170 (36.32) | ||
| Blastocyst expansion stage/case (%) | 1.596 | 0.085 | ||
| Phase 3 | 11 (3.42) | 18 (3.84) | ||
| Phase 4 | 282 (87.58) | 410 (87.61) | ||
| Phase 5 | 24 (7.45) | 32 (6.84) | ||
| Phase 6 | 5 (1.55) | 8 (1.71) | ||
| Blastocyst transfer day/case (%) | 8.158 | 0.010 | ||
| D5 | 295 (91.6) | 410 (87.61) | ||
| D6 | 27 (8.39) | 58 (12.39) | ||
| Fertility rate/case (%) | 16 (4.97) | 35 (7.48) | 8.676 | 0.005 |
2.3. 影响囊胚移植妊娠结局的多因素分析
将年龄、不孕年限、移植日内膜厚度、优质囊胚率、内细胞团评级、滋养层细胞评级、多产、囊胚移植日纳入多因素logistic回归分析，设Y：非活产=1，活产=0。结果显示，年龄>35岁、不孕年限>5年、移植日内膜厚度<9 mm、滋养层细胞评级为C级、囊胚移植日为D6、多产均为体外受精-胚胎移植非活产的危险因素（P<0.05）。见表3。
表 3. Multivariate analysis of factors affecting pregnancy outcome of blastocyst transfer.
影响囊胚移植妊娠结局的多因素分析
| Factor | Partial regression coefficient | Standard error | Wald | Odds ratio | P | 95% confidence interval |
| Age (≤35 yr.) | ||||||
| >35 yr. | 1.079 | 0.501 | 4.630 | 2.942 | 0.031 | 2.492-4.095 |
| Years of infertility (≤5 years) | ||||||
| >5 years | 0.583 | 0.435 | 1.799 | 3.793 | 0.017 | 2.846-3.965 |
| Endometrial thickness on transplantation day (≥9 mm) | ||||||
| <9 mm | 1.102 | 0.468 | 5.544 | 3.012 | 0.018 | 2.684-4.348 |
| High-quality blastocyst rate (≥65%) | ||||||
| <65% | 0.669 | 0.360 | 3.453 | 1.254 | 0.063 | 0.499-1.739 |
| Inner cell cluster rating (Grade A+Grade B) | ||||||
| Grade C | 0.606 | 0.457 | 1.756 | 1.034 | 0.185 | 0.593-1.485 |
| Trophoblast cell rating (Grade A+Grade B) | ||||||
| Grade C | 0.577 | 0.204 | 7.996 | 3.782 | 0.004 | 3.283-4.174 |
| Blastocyst transfer day (D6) | ||||||
| D5 | 0.699 | 0.307 | 5.165 | 3.012 | 0.023 | 2.783-3.573 |
| Fertility (no) | ||||||
| Yes | 0.689 | 0.340 | 4.096 | 2.993 | 0.042 | 2.593-3.717 |
3. 讨论
本研究多因素分析结果显示，年龄>35岁、不孕年限>5年、移植日内膜厚度<9 mm、滋养层细胞评级为C级、囊胚移植日为D6、多产均为体外受精-胚胎移植非活产的危险因素（P<0.05）。①年龄>35岁的女性群体卵泡内环境及卵子质量明显衰退，随着年龄的增长胚胎着床和宫内继续妊娠能力也逐渐降低[9-10]。有学者也指出女性排卵日的子宫内膜也随着年龄的增长而变薄，子宫内膜间质细胞中雌激素受体水平降低，内膜及膜下血管血流量等减少，降低了子宫内膜容受性，进而降低了临床妊娠率、活产率等[11]。②不孕年限>5年的孕妇，一方面可能因年限过长而延误了病情，增大了治疗难度；另一方面随着不孕年限的延长说明孕妇年龄也较高，高龄患者子宫情况和生育能力衰减，降低了临床妊娠率和活产率[12]。③子宫内膜充分增生并向分泌期转化是胚胎着床的必要条件，临床中可通过监测子宫内膜厚度了解其增生程度，判断其是否适合胚胎着床，移植日内膜厚度<9 mm说明子宫内膜增生程度较低，子宫容受性降低，进而影响了临床妊娠率[13]。但也有学者指出移植日的子宫内膜厚度过厚也会对胚胎着床产生不良影响[14]，进而降低妊娠率，目前尚存争议，因此今后需进一步探究。④滋养层细胞评级为C级对囊胚的质量产生了影响，进而影响了囊胚发育速度，降低了临床妊娠率[15]。⑤既往有学者指出D5囊胚移植和D6囊胚移植的妊娠结局并无明显差异[16]，但本研究结果显示D5囊胚移植的临床妊娠率和活产率明显优于D6囊胚移植，D6囊胚的发育速度较D5囊胚发育速度延迟，且发育潜能较低，随着体外培养时间的延长，DNA受损加重，易出现囊胚后续发育潜能低下，进而影响临床种植率，造成不良妊娠结局[17-18]。⑥已知多产患者的多种妊娠并发症的发生率明显高于单胎妊娠，且进行体外受精-胚胎移植的患者年龄均相对较大，因此其身体的各项机能均受到影响，易出现不良妊娠结局，而降低活胎率。
综上所述，年龄、不孕年限、移植日内膜厚度、滋养层细胞评级、囊胚移植日、多产均与体外受精-胚胎移植不良妊娠结局相关，应积极监测，采取有效措施预防不良妊娠结局。但本研究中所纳入的研究对象仅为我院所收治，所获得的研究结果可能受到地域限制，因此今后研究也应逐步扩大范围，以提高结果准确性。
* * *
利益冲突 所有作者均声明不存在利益冲突
Funding Statement
河南省医学科技攻关计划项目（No. LHGJ20200421）资助
References
- 1.DONGARWAR D, SALIHU H M Risk of stillbirth after infertility treatment in the United States: 2014−2017. Int J Mch Aids. 2020;9(1):149–152. doi: 10.21106/ijma.345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.MARIA K H, NATALIE C E, BROOKE H C, et al. Live birth rates, infertility diagnosis, and infertility treatment in women with and without multiple sclerosis: Data from an administrative claims database. Mult Scler Relat Disord, 2020, 46(11): 102541[2021-05-021]. https://doi.org/10.1016/j.msard.2020.102541.
- 3.LIU C, SU K, TIAN M, et al Effects of three abnormal conditions of fallopian tube on outcomes of thein vitro fertilization and embryo transfer technique . J Obstet Gynaecol Res. 2020;46(8):1412–1418. doi: 10.1111/jog.14306. [DOI] [PubMed] [Google Scholar]
- 4.NINA O, ANDREA D, ANASTASIA I N, et al Incidence of pulmonary and venous thromboembolism in pregnancies after in vitro fertilization with fresh respectively frozen‐thawed embryo transfer: Nationwide cohort study . J Thromb Haemost. 2020;18(8):1965–1973. doi: 10.1111/jth.14840. [DOI] [PubMed] [Google Scholar]
- 5.许月明, 张杰, 尹力, 等 低体质量对体外受精-胚胎移植妊娠结局的影响. 国际生殖健康/计划生育杂志. 2020;39(2):101–103. doi: 10.3969/j.issn.1674-1889.2020.02.003. [DOI] [Google Scholar]
- 6.谷保霞, 王璐, 尚小改, 等 赠受卵双方体外受精-胚胎移植助孕结局的临床分析. 中华生殖与避孕杂志. 2020;40(4):309–313. [Google Scholar]
- 7.SHIRAZI M, POORANSARI P, HAJIHA N, et al Effect of single-dose methotrexate treatment on ovarian reserve in women with ectopic pregnancy undergoing infertility treatment: A single-center experience. Int J Fertil Steril. 2020;14(1):23–26. doi: 10.22074/ijfs.2020.5938. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.ALIBEIGI Z, JAFARI DE, KHEIRI S, et al The impact of traditional medicine-based lifestyle and diet on infertility treatment in women undergoing assisted reproduction: A randomized controlled trial. Complement Med Res. 2020;27(4):230–241. doi: 10.1159/000505016. [DOI] [PubMed] [Google Scholar]
- 9.张斌, 焦熙堯, 李华, 等 小鼠4倍体胚胎诱导蜕膜化反应. 解剖学报. 2021;52(1):124–129. [Google Scholar]
- 10.王楠, 茅彩萍, 吕金星, 等 体外受精鲜胚移植患者妊娠结局的预测因素研究. 中国血液流变学杂志. 2020;30(3):358–362. doi: 10.3969/j.issn.1009-881X.2020.03.024. [DOI] [Google Scholar]
- 11.黄莹, 覃爱平 两种授精方式在高龄低获卵患者体外受精-胚胎移植中的应用效果比较. 广西医学. 2020;42(15):1981–1984. [Google Scholar]
- 12.CAITLIN R S, AMY L H, KAITLYN J, et al. Placental pathology in live births conceived with in vitro fertilization after fresh and frozen embryo transfer. Am J Obstet Gynecol, 2020, 222(4): 360[2021-05-21]. https://doi.org/10.1016/j.ajog.2019.09.047.
- 13.陈华, 鲁南, 杨岳州, 等 剖宫产切口瘢痕以及憩室对体外受精-胚胎移植后妊娠结局的影响. 中华生殖与避孕杂志. 2020;40(6):447–453. doi: 10.3760/cma.j.cn101441-20200421-00231. [DOI] [Google Scholar]
- 14.XUE X, SHI W H, ZHOU H Y, et al. Cumulative Live Birth Rates According to Maternal Body Mass Index After First Ovarian Stimulation for in vitro Fertilization: A Single Center Analysis of 14, 782 Patients. Front Endocrinol, 2020, 11(9): 149[2021-04-30]. https://doi.org/10.3389/fendo.2020.00149.
- 15.王超, 姚颖, 郑丹蕾, 等 体外受精-胚胎移植后剖宫产瘢痕妊娠发病与诊治分析. 中华医学杂志. 2020;100(47):3759–3763. doi: 10.3760/cma.j.cn112137-20200518-01573. [DOI] [PubMed] [Google Scholar]
- 16.李国臻, 段新崇, 杨志伟, 等 冻融周期中D 5、D 5加D 6、D 6期囊胚移植妊娠结局比较. 中国计划生育和妇产科. 2019;11(7):24–27. doi: 10.3969/j.issn.1674-4020.2019.07.07. [DOI] [Google Scholar]
- 17.沈金华, 周雅倩, 阳益德, 等 父亲年龄对体外受精-胚胎移植术后妊娠结局影响的Meta分析. 中国男科学杂志. 2020;34(4):13–20. [Google Scholar]
- 18.ALEXANDER V P, TUYET N T N, TOGAS T, et al Impact of intramural non-cavity-distorting leiomyoma on placental histopathology and perinatal outcome in singleton live births resulting from in vitro fertilization treatment . J Assist Reprod Genet. 2020;37(8):1963–1974. doi: 10.1007/s10815-020-01867-7. [DOI] [PMC free article] [PubMed] [Google Scholar]