Study finds blastocyst quality has little impact on perinatal outcomes in single frozen-thawed transfers
image: Single frozen-thawed high-quality blastocyst transfer singleton pregnancies were associated with significantly higher rates of biochemical pregnancies (66.6% vs. 49.0%; P <0.001), clinical pregnancies (62.4% vs. 44.1%; P <0.001), ongoing pregnancies (50.8% vs. 33.3%; P <0.001), and live births (49.9% vs. 32.4%; P <0.001) compared to single frozen-thawed poor-quality blastocyst transfer pregnancies.
Credit: Wu, Jing; Yang, Chen; Zheng, Wei; Cao, Meng-Yi; Li, Meng-Na; Kuang, Yi-Hui; Ren, Bing-Nan; Zu, Ruo-Wen; Shen, Ran; Han, Jing-Yi; Li, Pei-Xin; Guan, Yi-Chun.
A new study from the Third Affiliated Hospital of Zhengzhou University suggests that the quality of blastocysts used in single frozen-thawed blastocyst transfer (SFBT) cycles may not influence perinatal outcomes, offering reassurance to patients who may not have access to high-quality embryos.
The retrospective cohort study compared outcomes from high-quality and poor-quality blastocyst transfers. Researchers examined maternal obstetric outcomes, including gestational hypertension, diabetes, premature rupture of membranes, placenta previa, and cesarean delivery rates, as well as neonatal outcomes such as birth weight, preterm birth, and birth defects.
“Our results show no significant differences in maternal or neonatal outcomes between high-quality and poor-quality blastocyst transfers,” said Dr. Yi-Chun Guan, the study’s corresponding author. “This is encouraging for patients who might only have lower-quality embryos available for transfer.”
Once a blastocyst successfully implants, the development of trophoblast cells and the formation of the placenta are largely unaffected by the initial morphological quality of the embryo. Researchers also note that factors such as maternal health, hormone balance, and genetic influences may have a more decisive role in determining perinatal outcomes than embryo morphology.
While previous research linked embryo quality to pregnancy success, this study emphasizes that poor-quality blastocysts can still lead to healthy pregnancies and births when transferred individually in SFBT cycles. The authors highlight that this is one of the largest cohort studies to focus solely on blastocyst quality and perinatal outcomes, with data drawn directly from electronic medical records to enhance accuracy.
The study provides valuable guidance for reproductive medicine, potentially reducing anxiety for patients undergoing assisted reproductive technology and supporting more flexible embryo transfer strategies in clinical practice. The research findings are published in Reproductive and Developmental Medicine.