Reproductive history does not compromise subsequent live birth and perinatal outcome following in‐vitro fertilization: analysis of 25 329 first frozen–thawed embryo transfer cycles without preimplantation genetic testing for aneuploidy

ABSTRACT Objective To investigate the effect of women's reproductive history on live‐birth rate and perinatal outcome after first frozen–thawed embryo transfer (FET) without preimplantation genetic testing for aneuploidy. Methods This was a retrospective cohort study of women who had undergone their first FET cycle between January 2014 and December 2020 at a university‐affiliated fertility center. No transferred embryo underwent preimplantation genetic testing for aneuploidy. The women were categorized into five groups based on their reproductive history: no previous pregnancy; previous termination of pregnancy (TOP); previous pregnancy loss; previous ectopic pregnancy (EP); and previous live birth. The women with no previous pregnancy were considered as the reference group. The primary outcome was the live‐birth rate and secondary endpoints included rates of positive pregnancy test, clinical pregnancy, pregnancy loss and EP as well as perinatal outcomes such as birth weight and preterm birth. Multivariable logistic regression analyses were used to control for a number of potential confounders, including age, body mass index, education level, duration and cause of infertility, insemination method, type of endometrial preparation, number of embryos transferred, embryo developmental stage, quality of the embryos transferred, year of treatment and endometrial thickness. Additionally, propensity score matching (PSM) was used to check the robustness of the main findings. Results In total, 25 329 women were included in the final analysis. On univariate analysis, each reproductive‐history type except for previous EP was significantly associated with worse pregnancy outcome following in‐vitro fertilization (IVF), including rates of positive pregnancy test, clinical pregnancy, pregnancy loss and live birth, when compared with the group of women with no previous pregnancy. However, after correcting for several potential confounders, the differences in rates of live birth, pregnancy loss, positive pregnancy test and clinical pregnancy were no longer significant between the study and control groups on multivariable regression models, while the risk of EP after embryo transfer was elevated among women with a previous TOP or EP. There was no increased risk of adverse perinatal outcome associated with reproductive history compared with the control group. Notably, similar results were obtained from the PSM models, confirming the robustness of the main findings. Conclusion Relative to women without a previous pregnancy, those with a prior TOP, pregnancy loss, EP or live birth did not have compromised live‐birth rate or perinatal outcomes following FET without preimplantation genetic testing for aneuploidy, with the exception of an increased risk of EP in those with prior TOP or EP. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.