Abstract
BACKGROUND AND AIMS: It is demonstrated that lipid metabolism disorders are associated with the reproductive performances of assisted reproductive technology. However, it is little known whether hyperlipidemia is associated with the endometrial receptivity and pregnancy outcomes of patients undergoing frozen-thawed embryo transfer (FET). METHODS: This was a retrospective analysis involving 554 infertile women undergoing FET. The patients were divided into the hyperlipidemia group (n = 224) and control group (n = 320) based on the levels of serum lipids. The clinical and laboratory indexes between the two groups were compared. Meanwhile, the stratified analysis based on body mass index (BMI) and endometrial preparation protocols was performed. The independent samples t-test, Mann-Whitney U test, χ2 test and multiple logistic regression analysis were used to compare and analyze the data. RESULTS: The patients with hyperlipidemia had significantly higher serum lipids levels and BMI and lower clinical pregnancy and implantation rates than those with normal blood lipids (p < 0.05). The impact of hyperlipidemia on pregnancy outcomes was independent of BMI. The multiple logistic regression analysis showed that higher cholesterol was associated with lower pregnancy rate and implantation rate (p < 0.05). Regardless of blood lipid levels, the patients undergoing the hormone replacement therapy (HRT) protocol had higher estradiol levels and lower progesterone levels compared with the stimulated cycles (STC) (p < 0.05). Moreover, the clinical pregnancy rate and implantation rate of the HRT protocol were higher than those of the STC, although there was no significant difference between the two. CONCLUSION: Hyperlipidemia especially higher cholesterol has a negative effect on the pregnancy outcomes of the patients undergoing FET. Actively implementing lipid-lowering treatment and the HRT protocol seem more friendly for these patients.