氧浓度对体外培养胚胎发育的影响

Effect of different concentrations of oxygen on the development of embryos cultured in vitro

目的:探讨体外受精/卵胞质内单精子注射(IVF/ICSI)后移植前胚胎在不同氧浓度培养条件下的发育情况。方法:将接受IVF或ICSI的患者随机分组成常氧组(体积分数20%的氧浓度,包括IVF卵裂期胚胎患者150例,IVF囊胚期胚胎患者51例,ICSI卵裂期胚胎患者81例,ICSI囊胚期胚胎患者39例)和低氧组(体积分数5%的氧浓度,包括IVF卵裂期胚胎患者108例,IVF囊胚期胚胎患者56例,ICSI卵裂期胚胎患者79例,ICSI囊胚期胚胎患者45例),观察各组胚胎在受精后第3日的卵裂胚和第5日的囊胚发育情况以及临床妊娠结局。结果:在患者年龄、不孕年限、基础FSH值、Gn用量、获卵数和MⅡ卵率组间均无统计学差异的基础上,1与常氧组相比,低氧组的胚胎IVF或ICSI后的受精率、卵裂率以及第3日形成的优质胚胎率无统计学差异(P>0.05),临床妊娠率和着床率组间也无统计学差异(P>0.05);2低氧组胚胎IVF或ICSI后形成的Ⅴ级囊胚多于常氧组(P<0.05),总囊胚形成率组间有显著的统计学差异(P<0.01),临床妊娠率和着床率组间无统计学差异(P>0.05)。结论:与常氧培养条件相比,低氧培养条件并不能显著促进IVF/ICSI后卵裂期胚胎的发育,但能够促进囊胚的形成,特别是囊胚的孵出,因此低氧培养可以作为囊胚培养的首选条件,但不是卵裂期胚胎培养的必要条件。

Objective： To investigate the development of pre-implantation embryos under different concentrations of oxygen after in vitro fertilisation/intracytoplasmic sperm injection （IVF/ICSI）. Methods： The embryos of IVF or ICSI were randomly divided into normal oxygen group （20% oxygen, including 150 cases in IVF ongoing cleavage embryo culture, 51 cases in IVF ongoing blastula culture, 81 cases in ICSI ongoing cleavage embryo culture and 39 cases in ICSI ongoing blastula culture） and low oxygen group （5% oxygen, including 108 cases in IVF ongoing cleavage embryo culture, 56 cases in IVF ongoing blastula culture, 79 cases in ICSI ongoing cleavage embryo culture and 45 cases in ICSI ongoing blastula culture） and then the development of cleavage embryos on day 3 and blastula on day 5 were compared between the two groups. Results： On the basis of no statistical difference in age, duration of infertility, basal FSH value, Gn used dosage and M H oocyte rate between normal oxygen group and low oxygen group, 1） there were no statistical difference in the rates of fertilization, cleavage and good-quality embryo cultured on day 3 between the two groups both in IVF and ICSI and no statistical difference existed on the clinical pregnancy rate and the implantation rate; 2） the number of grade V blastula formed in low oxygen group was statistically higher than that in normal oxygen group both after IVF and ICSI （P〈0.05） and the total blastula formation rate in low oxygen group was significantly higher than that in normal oxygen group （P〈 0.001 and P〈0.01, respectively）. Although the clinical pregnancy rate and the implantation rate were higher in low oxygen group than in normal oxygen group, the difference between them was not statistically significant. Conclusion： Compared with normal oxygen culture, low oxygen culture can＇t significantly improve the development of cleavage embryos, but can enhance the formation of blastula, especially the hatching of blastocysts. All these findings indicate that low oxygen culture is prior in blastula culture but not in cleavage embryo culture.