Influencing Factors of Pregnancy Outcome of in vitro Fertilization-Embryo Transfer

  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.