The outcomes of sequential embryo transfer in patients undergoing in vitro fertilization with frozen–thawed embryos: A retrospective study

Abstract

Aim: To explore whether sequential embryo transfer benefits patients with repeated implantation failure (RIF) undergoing frozen-thawed embryo transfer (FET) cycles. Methods: We included 311 patients with a history of RIF in this retrospective study. We did sequential transfers with a cleavage embryo on day 3 and a blastocyst on day 5 in 77 patients; blastocyst transfers with two blastocysts on day 5 in 80 patients; and cleavage embryo transfers with two cleavage embryos on day 3 in 154 patients. We compared clinical outcomes between the three groups.Results: The clinical pregnancy rate was comparable between the blastocyst transfer group (48.8%), the sequential transfer group(48.1%) and the cleavage embryo transfer group (48.1%). There was no statistically significant difference found (p > 0.05). The ongoing pregnancy and multipregnancy rates were also comparable between the three groups (p > 0.05). The early miscarriage rate was significantly higher in the sequential transfer group (32.4%) compared with the blastocyst group (12.8%) and the cleavage embryo group (12.2%) (p < 0.05). However, after adjusting for confounders, there was no significant difference in early miscarriage rates in the sequential transfer group compared with the blastocyst group (odds ratio [OR], 2.97; 95% confidence interval [CI], 0.85-9.24; p = 0.07) and the cleavage embryo group (OR, 3.03; 95% CI, 0.94-8.06; p = 0.08). Conclusions: Sequential embryo transfer failed to improve clinical outcomes for patients with RIF.

Effects of sequential and fixed-dose estradiol valerate administration on premature progesterone rise in frozen-thawed embryo transfer cycles

“…In the cycles following IVF, more mature follicles are formed due to the use of ovarian stimulating drugs, so the level of these hormones can be higher than the physiological state. This increase in level can cause concern about luteal phase disorders and uterine tissue changes (7). E2 first causes hyperplasia and hypertrophy of endometrial epithelial cells (9), but its role in the luteal phase is unclear (8).…”

“…In the conducted studies, the harmful effect of high E2 on the receptivity of the endometrium has been proposed (4,5); however, in some studies, this negative effect has not been reported (6,7). The role of E2 in the follicular phase, including the proliferation of stroma and glandular epithelial vessels in the endometrial tissue, has been discussed (5,6).…”

“…The changes in endometrial vessels occurs following the coordination between the actions of E and P4, which causes the adequate blood supply to the endometrium to accept the pregnancy (8). Subendometrial and endometrial vascularity has significantly decreased in women with unexplained infertility (6,7). The junction of the endometrium and myometrium is rich in blood vessels and plays a significant role in embryo implantation (9).…”

“…Both P4 and E2 are necessary to prepare the endometrium for blastocyst implantation and successful pregnancy (6,7). In the cycles following IVF, more mature follicles are formed due to the use of ovarian stimulating drugs, so the level of these hormones can be higher than the physiological state.…”

The Embryological Characteristics and Clinical Outcomes of Oocytes with Indented Zona Pellucida

“…The cryopreserved embryos are used for subsequent frozen embryo transfer (FET). The transfer protocol included sequential transfer, embryo transfer and blastocytes transfer [21]. It referred that patients were transferred 1-2 frozen embryos and/or blastocytes after ovulation 3 and/or 5 days, respectively.…”