A comparison of pregnancy rate between natural cycle and hormone replacement cycle in patients who underwent frozen embryo transfer using 2 consecutive hormone replacement regiments

Abstract

For frozen embryo transplantation patients who failed to use hormone replacement cycle (HRC) transplantation for 2 consecutive times, the third time of transplantation was divided into 2 groups: HRC and natural cycle (NC), and the pregnancy rate of the 2 groups, especially the clinical pregnancy rate, was compared. Retrospective study of 174 patients in the reproductive medicine center of an affiliated hospital of Shandong University of Traditional Chinese Medicine between January 2015 and September 2018. The 174 patients were all infertile with regular menstruation. They had undergone 2 consecutive failed cycles of endometrial preparation with hormone replacement therapy and prepare for the third frozen embryo transplantation. A third cycle of treatment was planned using either NC or HRC for endometrial preparation. All the embryos were obtained during the same oocyte retrieval cycle. Patients were divided into groups based on the method of endometrial preparation: 98 were classified as NC and 76 as HRC. The pregnancy outcomes for the 2 groups were compared. Confounding factors that may affect clinical pregnancy rates were analyzed. We found that on the day of endometrial transformation, estrogen levels and endometrial thickness in the NC group were significantly higher than those in the HRC group. There were no significant differences in the rates of biochemical pregnancy, clinical pregnancy, cumulative pregnancy, miscarriage, multiple pregnancy, ectopic pregnancy, or live birth between the 2 groups. It is concluded by binary regression analysis that the different endometrial preparation protocol have no significant effect on the CPR. NC is as effective as HRC after 2 previous cycles of HRC. Because this was a retrospective study design, selection bias is possible, although the baseline characteristics of the 2 groups of patients were matched.

Placenta Accreta Spectrum Disorder Complicated with Endometriosis: Systematic Review and Meta-Analysis

“…A previous retrospective study that determined an association between endometrial thickness and placenta previa found that women with endometrial thickness more than 12 mm were more likely to have placenta previa (adjusted OR 3.74, 95%CI, 1.90–7.34) than women with endometrial thickness less than 9 mm [ 76 ]. Previous studies have reported that the endometrial thickness was thinner in women who conceived with frozen ET than in women who conceived with fresh ET [ 76 , 107 , 108 ]. Therefore, a possible mechanism for the decreased rate of placenta previa for women who conceived using frozen ET is the thinner endometrial thickness.…”

Effect of different endometrial preparation protocols on pregnancy outcomes in frozen- embryo transfer cycles: a retrospective cohort study

“…Compared to the other three groups, the HRT group having the lowest endometrial thickness at one day before transplantation. Two retrospective cohort studies also showed that the endometrial thickness was less in the HRT group than in the NC group (29,30).However, there was no statistical difference in the incidence of biochemical pregnancy, clinical pregnancy, miscarriage or live birth between the two groups(30), probably because endometrial thickness is not a decisive parameter for successful pregnancy (31). However, a study by Shaodi et al (2020) showed that to obtain optimal live birth rate, the endometrial thickness must remain within the range of 8.7-14.5mm as too thin or too thick endometrium would reduce the live birth live (32) .More studies are needed to address the effect of endometrial thickness on pregnancy outcome.…”